Saturday, October 31, 2009

Spooky Speleothems for a Saturday Scarefest

To be perfectly honest, I really detest the part of a cave tour when some teenaged guide who knows nothing of the geology goes on and on about how a particular cave decoration (speleothem) looks like a dragon or a elephant or whatever. On the other hand, the human mind has a great capacity for constructing forms and patterns out of totally random scenes. So, in honor of All Hallow's Eve I offer a picture I snapped in Lewis and Clark Caverns in Montana. I don't know about you, but I see at least one scary looking ghost and a cackling witch. What do y'all see?

Watch out for that candy coma tonight, and don't run over any trick or treaters!

Thursday, October 29, 2009

Hosing Down the Mother Lode: Hydraulic Mining

Continuing our journey through the Sierra Nevada Mother Lode on our field studies trip last weekend, we arrived at Chili Gulch south of the town of Mokelumne Hill to talk about another way of wresting gold from the earth. We were gathering at a rather poor roadcut when a local rancher drove up and offered to let us onto his property where the walls of an old hydraulic mine could be seen. I was thrilled (ranchers don't always like geologists, as many of you know). The picture above shows some of the Tertiary "Auriferous" Gravels exposed in the old quarry wall. These gravels were obviously carried and deposited by a vigorous river, but at this point we were several thousand feet above the present-day Mokelumne River. How did river gravels end up near the top of a mountain??

The trick is to realize how much the topography of the Sierra Nevada has changed in 50 million years. If one were able to travel back to that era, a flight over the Mother Lode would have revealed a shoreline where the Central Valley is today. The shoreline would merge into swampy estuaries and lagoons, and every so few miles along the coast a large river would be flowing into the sea. Looking eastward would reveal a surprise: where the present Sierra Nevada Crest pierces the skyline there would be...no mountains! They had not yet risen (I hereby acknowledge that there is some fierce debate about the uplift history of the Sierra). Instead, the rivers would be flowing from sourcelands in central Nevada, or maybe even farther north and east (one has to wonder where the diamonds came from). The path of the rivers through the Sierra is fairly well established, and becomes more speculative as one travels farther east (see the map below).

Ash eruptions and lava flows covered parts of the Sierra Nevada while the mountains were rising, and rivers were diverted to their present-day channels. The rivers carved deep canyons as the mountains rose, isolating the patches of older stream gravels on the adjacent ridge tops.

It didn't take the forty-niners long to dig up and process all the gold-bearing gravels in the present-day rivers of the Mother Lode: they were pretty well played out by 1853. Some enterprising (i.e. hungry) miners started exploring the slopes and mountains above and soon found the Tertiary River Gravels, but there was a problem: they needed water to sift through the gold-bearing sediment, and water was not abundant on the mountain ridges.

It did not take the miners very long to come up with an ingenious and devastating solution to their problem. They built reservoirs in the high country near the Sierra Crest, and diverted the water before it flowed into the deep canyons. Using literally thousands of miles of flumes, canals and penstocks, they delivered water to the mines on the mountain tops, and using giant nozzles (called monitors) they blasted the cliff with stream of high pressure water (photo below). They had (re)invented hydraulic mining, one of the most destructive human activities to ever affect the Sierra Nevada and adjacent Central Valley.

To capture the gold, large riffles were carved in the rock where the water left the mine quarry. Hundreds of pounds of mercury sat in the riffles to amalgamate the gold, although the sheer quantity of water swept much of the mercury (and plenty of gold) downstream. Of course, ALL of the loosened debris was sent downstream as well, and there was a LOT of it. What was left behind was widespread devastation.

The hydraulic pits were cleared of all topsoil, and many square miles of forest were washed away, sometimes to a depth of several hundred feet (the original surface of the mine shown above coincided with the gray ledge on the far ridge). In a few places, like Malakoff Diggings State Park, the old quarries have taken on a vaguely Bryce Canyon-type beauty, but that is the exception.

Downstream, sediment choked river channels many tens of feet deep. In the picture below, the full thickness of the tailings can be seen in the terrace at the top of the photo. The stumps in the channel are actually the fifty foot level of mature trees that were buried in the gravel. The mud and silt continued downstream to fill the shallow channels of rivers in the Central Valley. Flooding became a yearly problem in towns like Yuba City and Marysville. About 40% of San Francisco Bay filled with mud from the mining operations. The total amount of sediment (1.5 billion cubic yards) was eight times what was moved to dig the Panama Canal.

The devastation of the mining finally drove the victims to court, and in 1884 the Sawyer Decision declared that the hydraulic mines had to confine the waste sediments to the mine property. The ruling effectively ended large-scale hydraulic operations in the Sierra, but the not pollution problems. Mercury continues to contaminate the mine properties, the sediments downstream, and San Francisco Bay. At some of the worst mine sites, an ounce of mercury could be panned out of two pounds of sediment.

As an aside, a few years I was watching the movie "Pale Rider", the Clint Eastwood western. It was set in the Gold Rush era Sierra, and the good guys were the gentle placer miners, who with their gentle and beautiful wives and children gently pulled gold from the little streams near their village. The bad guys of course were hydraulic miners who wanted to destroy the bucolic little town. The pictures of the hydraulic mines were well done, and there was, as I recall, a mention of the Sawyer Decision that ended the mining. They solved all the problems at the end of the movie by shooting at each other, of course.

Wednesday, October 28, 2009

Cave Bacon and Stalactites on Drugs: The Mother Lode Underground


During our field trip outdoors last weekend, we spent a lot of time underground. One of our stops included a tour of Black Chasm Cavern near the town of Volcano in the Mother Lode of the Sierra Nevada. It is a strikingly beautiful cave in a region that is not really known for its cave systems, but they are there and they are a truly unique place to learn about geological processes in the Sierra Nevada.

Most people, if they ever think of it all, will associate the Sierra Nevada with granite, an igneous rock that forms from the slow cooling of magma miles beneath the surface. As a point of fact, only about three-quarters of the Sierra is composed of granitic rocks, and only a small percentage of that is technically granite (mostly it is granodiorite). The remainder of the range is covered by volcanic rocks, or is composed of older metamorphic rocks, including a significant amount of marble. Marble is derived from the heating and deformation of limestone, which formed on the floors of Mesozoic and Paleozoic tropical seas, possibly as coral reefs or carbonate shelf deposits. The rocks were lifted from the ocean floor and added to the edge of the North American continent when the terranes collided with the Cordilleran subduction zone in Mesozoic time.

Marble, like the limestone from which it was derived, is composed of the mineral calcite. Weak acids in the soil and groundwater react with the calcite, carrying it away in solution, forming the openings that eventually become the caverns. As the Sierra Nevada rose and deep canyons were eroded across the range, the groundwater table dropped, exposing the caverns to the atmosphere. Water dripping or seeping into the cavern evaporates, leaving behind the mineral deposits that hang from the ceiling of the cave or rise from the floor (dripstone deposits), or which cover the walls of the cave (flowstone deposits). Collectively these cave decorations are called speleothems.

More than 1,000 caverns grace the Sierra Nevada foothills. Some of the caves are world-class in their intricacy and decoration. One cave in Kings Canyon National Park has more than 2o miles of passageways. Many of the caves are also extremely dangerous: most are developed in vertical passageways with deep unexpected dropoffs, and these serve as sinks for "bad" air (carbon dioxide is a heavier gas). On the other hand, some of the very nice caves are open for guided tours: Crystal Cave in Sequoia National Park, Boyden Cave near Kings Canyon, Moaning Cave north of Columbia, Mercer Cavern at Murphys, California Cavern up the hill from San Andreas, and Black Chasm, site of our exploration last week. A trail near New Melones Reservoir leads to the Natural Bridges, where Coyote Creek flows through a cavern.

Black Chasm is named for the deep cleft not far from the cavern entrance that drops 90 feet or so into a small lake. The lake extends at least another 60 feet downwards into the mountain. The chasm prevented the miners and other early explorers from exploring (and vandalizing) the more remote passages of the cave. As a consequence, the owners were able to develop the cave with a mind towards preserving the most pristine parts of the cave. They constructed stairwells and pathways across the chasm, with handrails preventing visitors from accessing and breaking the most fragile speleothems. The cave was opened for tours about 2001, and it quickly became my favorite choice for our geology field trips.

Besides the well-placed lighting system that highlights some beautiful draperies (cave bacon) and stalactites (see the second picture), the cavern offers some of the best developed helictites to be found anywhere (top picture). Helictites are essentially stalactites that have forgotten to follow the law of gravity. The precise details of the their origin are enigmatic, but water pressure clearly plays a greater role than gravity does. They are exceedingly fragile and are usually the first things to be vandalized in unprotected caves. Black Chasm has a spectacular wall covered with them (my photo is of a small corner of the entire panel).

The operators of Black Chasm offer a group discount, and the guides enjoy speaking to geology groups when they get the opportunity. It is well worth a visit!

If you are interested in exploring wild caves, preservation and protection is the highest priority. As such, you should get in touch with the local grotto of the National Speleological Society if you want to be involved in protecting this special resource. If you have followed my blog for any period of time, you will know that I think that cave vandals are one of the lowest and most moronic forms of humanity in existence.

Tuesday, October 27, 2009

A Geology Professor Passes: Donald B. McIntyre


I've received word from Dr. Eric Grosfils at Pomona College that one of the professors from my days at Pomona has passed away. Dr. McIntyre was a truly unique teacher, challenging, sometimes frustrating, but an excellent professor. I look back and I realize I was not as ready for college as I thought I was when I arrived at Pomona in 1977. I had transferred from the local community college, and though I had done well enough, I was now entering one of the most highly regarded and challenging geology programs in the state. I felt like a fish out of water!

Dr. McIntyre taught a class on Global Tectonics. I thought was going to be told about divergent and convergent boundaries and evidence for continental drift and other basic "stuff". Instead, we were given the keys to the library, and a list of the original classic papers in plate tectonics to study so we could learn for ourselves not the basic facts, but what the original evidence was, what the detractors and opponents had to say, as a preparation to analyze the arguments in class. As a student in Dr. McIntyre's class, I had become, in essence, one of the researchers fighting the academic battles of the late sixties and early seventies. It was uncomfortable for me at the time, and yet a valuable life-changing lesson. Science isn't facts. Science is a process, a sometimes difficult process for gaining knowledge.

Dr. McIntyre could be almost imperious at times, and calling him "Donald" could earn a person a cold stare and silence. Yet most times, he was a warm and friendly person. He and his wife hosted a Christmas party for the students in the department every year I was there. It was a nice gesture for students who were sometimes several states or entire oceans away from their homes. I can remember him pulling a volume off the wall of his personal library to show me a passage on the history of mountain climbing in Scotland. The author had said that his climbing partner, one Donald McIntyre, if he ever fell off a cliff, would be licking the rocks on the way down to better identify them!

I worked in the department at Pomona for a couple of years while I decided the next step in my own educational journey. Serving as a laboratory and field assistant to Dr. McIntyre and the other professors at the school was as good an education as anything I ever learned in a classroom. I moved on in 1982. Dr. McIntyre retired and moved home to Scotland in 1989, and I occasionally heard of his activities through the school alumni announcements.

I finally was able to journey to Scotland in 2001, and my students and I were able to share a meal with Dr. McIntyre in Inverness. It was a wonderful evening. He was, as always, a gracious and polite conversationalist. It was good to see him again.

These are some of my personal remembrances of working with Dr. McIntyre. I invite you to see a bit more of his lifetime accomplishments at his website. He will be missed. The announcement from Pomona College follows:
Donald B. McIntyre, Professor Emeritus of Geology, died on October 21st in Scotland, where he had lived since retiring from the College in 1989. He was 86 years old.

A memorial service will be held on Friday, October 30, at 11:00 a.m. in St. John's Kirk, Perth, Scotland.

A native of Edinburgh, Professor McIntyre received B.Sc., Ph.D., and D.Sc. degrees from the University of Edinburgh and taught there before joining the Pomona faculty as an associate professor in 1954. The following year he succeeded A. O. Woodford as Department of Geology chair, a position he held for almost three decades. Professor McIntyre's research interests were diverse, and his achievements earned him numerous honors, among them Fulbright and Guggenheim fellowships. He was, his colleague Donald Zenger once wrote, "a scholar of the highest order."

Professor McIntyre was also a gifted teacher, winning two Wig awards here on campus and, in 1985, being named California Professor of the Year by the Council for the Advancement and Support of Education. In nominating him for the latter award, R. Stanton Hales noted: "It is known that one good question asked of McIntyre will earn at least two hours of personal instruction."

In lieu of flowers, members of the family have requested that donations in Professor McIntyre's honor be directed to one of two funds:

-- the Ewen McIntyre Upper Springland Fund; checks should be made out to the fund and sent to it c/o Ann McIntyre (17 Beaumont House, 15 N. St John's Place, Perth PH1 5SZ, Scotland UK). My understanding is that this fund helps support the home for the disabled where Donald and Ann's son, Ewen, currently resides.

-- the McIntyre Geology Fund at Pomona College (also called the Donald B. McIntyre-H. Stanton Hill Geology Fund), established in Donald's honor by H. Stanton Hill ('33) and Mary C. Hill in 1987; gifts/contributions intended for this fund can be sent to Pomona College, c/o Don Pattison, Office of Donor Relations, 550 North College Avenue, Claremont, CA 91711. In his remarks Stanton Hill directs that "this fund will be for the benefit of the students taught by Donald's colleagues and successors."

In addition, if anyone would like to share personal recollections of Professor McIntyre with his family and does not wish to send them to Ann directly, we would be pleased to receive, collate, and forward them along (please send such comments via email by December 1st, subject "Donald McIntyre", to https://webmail.yosemite.edu/owa/redir.aspx?C=4f27de7267174b68955d4b5890d81da5&URL=mailto%3aegrosfils%40pomona.edu). In a future communication, the department will also discuss developing plans for honoring Professor McIntyre at our annual alumni dinner, scheduled this year for the evening of February 17th, 2010.

The loss of such a highly regarded and cherished member of our community is never easy, and our thoughts are with Professor McIntyre's family in these difficult times.

Monday, October 26, 2009

So, What's Wrong With a Bit of Arsenic, Mercury and Sulfuric Acid in Your Drinking Water?


Top photo by Garry Hayes, bottom photo from the Kennedy Mine Foundation

The mining history of California's Mother Lode is fascinating, and in many ways downright scary. It is astounding to realize the length mine owners went to wrest those little flakes of metal from the ground, without regard to the Native Americans who inhabited the region for thousands of years, without regard to the communities of people both near by, and far downstream, and with a shocking disregard for their own workers, the men who risked their lives daily deep in the earth. And of course, the environment was an unknown concept. The gold was there; it therefore had to be pulled out. It was all about money, of course.

On our field trip this last weekend, we had a chance to explore some of the mine complexes in and around Jackson, on Highway 49 in the Sierra Nevada Mother Lode. Yesterday's post was about our tour underground at the Sutter Creek Mine. Another of our stops was at a fascinating city park, the Kennedy Mine Tailings Wheels.

The Kennedy Mine was one of giants of the hard rock mines of the Sierra Mother Lode. From 1860 to 1942, the mine produced around 1.7 million ounces of gold, worth about $17 billion at today's prices. At the time of the mine's closure (because of World War II), the workings had reached a depth of 5,912 feet, making it one of the deepest mines in the world (there are mines in South Africa that are more than 12,000 feet today). According to different sources, the length of the underground workings totaled at least 50 miles (and maybe over 100).

The earliest miners would have worked with candles (i.e. open flames), hand operated drills, and black powder for explosives (i.e. not so good in presence of open flames). Innovations in the late 1860's and 1870's included carbide lamps, steam powered drills, and dynamite (courtesy of Nobel, of the Nobel Prize). Still, not the best of work environments. No one wore hardhats. Miners operating the drills (called "widow-makers") got paid a lot more than everyone else, but developed silicosis within a few years, and died. Cave-ins and rockbursts were not uncommon events. One of the saddest episodes was in 1922 when a fire trapped 47 miners at the 4,600 foot level of the adjacent Argonaut Mine. Miners at the Kennedy worked feverishly to drill a tunnel to the Argonaut passage, but they were too late and the miners were lost.

The gold ore was brought to the surface and crushed using huge stamp mills. The tailings were treated with arsenic and mercury to remove the gold, and then stacked in huge piles around the mine property. Upon exposure to the atmosphere, many of the sulfide minerals were transformed into strong acids. Being upstream from the town of Jackson, the poisons were seeping into the domestic water supply. By 1914, the mine was "encouraged" by lawsuits and court actions to build a tailings reservoir a half mile away, and over two ridges from the mine property. The wheels were a unique invention used to transport the tailings slurry from the mine to the reservoir. The wheels had dozens of buckets that picked up the mush from the base of the wheel, and dropped them forty feet higher onto a flume that carried the debris to the next wheel. Four wheels were needed in total.

Jackson is a quiet tourist town today, and the wheels provide a photogenic stop on a tour of the Mother Lode. It certainly wasn't always picturesque, or quiet. The 100-stamp mill, and the wheels would have run 24 hours a day. The older photo (from the Kennedy Mine Foundation) shows the barren slopes and the spartan buildings that housed the wheels. The buildings were removed during World War II, and two of the wheels collapsed, in 1963 and 1971 (history of the wheels here).

The last owner of the Kennedy Mine had purchased the abandoned site in 1961, and her will stipulated that the property be preserved as a wildlife area and that the mine be protected as a historical site. The Kennedy Mine Foundation was established to do this in 1996, and they offer above ground tours of the mine site for a modest fee (especially for school groups).

Sunday, October 25, 2009

Powder Monkeys and Dead Canaries: The Underground History of California's Mother Lode

It's late October, so it was time to introduce some of my students to the history of the Sierra Nevada Mother Lode, the site of the California's 1848 Gold Rush that brought hundreds of thousands of people to the west coast of the United States, and forever changed life in the Sierra Nevada and the rest of the state (and not for the better if you happened to be Mexican or Native American). Interest in gold has expanded as the price these days has reached $1,050 per ounce.

We explored Highway 49 from Sutter Creek to Columbia, one of the richest sections of the Mother Lode. Part of the trip was an exploration of the Sutter Creek Mine (the Lincoln Project), which offers tours of part of the underground workings of this off and on gold prospect.

The picture above is the entrance to the mine shaft. The white cylinder on top of the opening is the ventilation system that keeps fresh air flowing through the mine.


We were taken by modified jeeps about a quarter of a mile into the mine. Unlike most of the Mother Lode mines, the Sutter Creek operation is fairly horizontal. It is just a bit eerie to leave the daylight behind and to go plunging into the darkness. The ventilation system is quite noisy. One of the people on the tour (not one of my students, I'm glad to say) pretty much lost it and had to be taken back out (she was not aware that the tour was an underground tour).


We were taken to the safety room, a sort of refuge in a time of crisis for the miners. The room has strongly reinforced walls, air and water lines, first aid equipment, and communication lines to the surface. It also makes a nice little auditorium for talking about the early history of mining for gold. The demonstration of working by candlelight, as the earliest miners did, was especially effective. If you were wondering about the title, the canary refers to the actual practice of carrying canaries in the mine to monitor oxygen levels, and powder monkeys were the young men and children who were responsible for carrying dynamite around in the mine.


We walked through a section of tunnel that followed the gold bearing quartz veins, and looked at "gold" exposed in the quartz above our heads (I don't want to sound skeptical, but the "gold" is in a different place every time I tour, and it is always three or four feet above our heads where we can't see it well...). The equipment they used in the old days was downright, even insanely dangerous. Not just the explosives; the drills kicked up large amounts of silica the miners inhaled. Many died after just a few years from silicosis. But the pay was good...

The operators of the tour do a pretty good job of describing historic and modern methods of mining for gold, although it may stretch your budget if you are there on your own. They offer a decent discount for student groups such as the group we had yesterday. If you are interested in checking it out, their website can be found here.

After our tour, we headed up the mountain towards the town of Volcano for our second underground adventure, at Black Chasm Cavern. That will have to wait until the next post!

Saturday, October 24, 2009

Light a Candle in the Darkness: Volunteering for Science in Your Community

Photo Source: Modesto Bee


I noticed some of my comic strips were running a theme of volunteerism this week. Well, now my blog is too (and this would also by my contribution to this month's Accretionary Wedge)...

Here in California, K-12 education is in pretty much a chaotic mess, and our children are being shortchanged in the worst way. Class size is growing, budgets are getting slashed, and some of our best teachers are being fired. These are bleak times, and our community college system is no better off. But I am proud of what my colleagues at Modesto Junior College are doing. You can read the story here, but in short we are bringing fifth graders onto our campus every other Friday to give them an experience in science and to introduce them to our college campus. Most of our division (biology, chemistry, physics and earth sciences) is volunteering to make the program a success. From the article:

About 60 students watched and performed experiments as part of MJC's Science Educational Encounters for Kids. Every second and fourth Friday of the month, fifth-graders converge on campus for a science lecture and then two 45-minute labs.

"We are drawing members of the community into the college. Some of these students maybe don't think college is a possibility, and we want to show them this is their community college," said Brian Sanders, dean of MJC's science, math and engineering division.

"Activities are a blend of fun and interest with real science," Sanders said. "We're not just playing with bubbles. We're matching the labs with the state's fifth-grade science standards."

And...these kids are a lot of fun, too. Full of energy and enthusiasm! Contact me if you would like more info on how we set up the program (hayesg at mjc dot edu).

Thursday, October 22, 2009

The Airliner Chronicles: Epicenter of a Geological Education

I had forgotten how much I enjoyed going through my aerial shots when I first started blogging, so I am reviving my Airliner Chronicles, just for the heck of it. I was on a flight to Williamsburg a few years ago when I realized with a start that I was flying right over my thesis area. Though I was never really thrilled with the final product, I did in fact complete the thesis and they let me graduate, to the heartache of 20 years worth of community college students who have taken my classes.

For my thesis, I was looking for evidence of Holocene faulting in the Sierra Nevada/Great Basin Boundary Zone in the area around the Sweetwater Mountains and Antelope Valley. The West Walker River flows through the area, on its way to evaporate in the sump of Walker Lake, a remnant of Pleistocene Lake Lahontan.

Some of my relatives had a house in Walker, California, that served as my base camp for the summers that I spent exploring the region (Walker is the village in the lower half of the photo; the house is one of those on the river just left of center). As can be seen in the photo above, the West Walker emerges from a deep canyon carved in typical Sierra Nevada granites, and forms a modified alluvial fan at the south end of Antelope Valley, a deep fault graben marking the edge of the Basin and Range Province. The bank of the West Walker River served as a wonderful outdoor lab on hydrological processes. Over a 15 year period I was able to monitor drought conditions, floods, bank erosion, and riparian vegetation changes. I learned a great deal, but there was nothing in my experience on the river to compare with the events of New Years Day, 1997.

For those of you who lived in California or western Nevada at the time, the floods of 1997 will be remembered for a long time. A record snowpack coated the Sierra Nevada, but a Pineapple Express, a warm tropical storm out of the Pacific, took aim at Central California. Precipitation amounts in a two day period reached as much of three feet, mostly falling as warm rain on the snowpack. Record flows were recorded on numerous rivers, but I don't think any of floods smashed the old records the way the West Walker did...until 1997, no flood had ever exceeded 6,800 cubic feet per second. On January 2, 1997, the river hit 12,500 cfs. This is an estimated 500 year flood (a one in 500 chance of occurring in any one year).

The effects on the little village and surrounding region were profound, to say the least. Highway 395, the primary north-south artery between Reno and the Los Angeles region, was simply erased in the ten miles upstream of Walker. The ripped up road fragments, granite boulders, and uprooted trees became battering rams that pounded the unprotected hamlet of 500 or so people. Numerous houses, cabins and businesses were washed away. Much of the floodplain adjacent to the river channel was buried under several feet of gravel and cobbles, and the original river course had been split into two or three separate channels. Flooding in Reno and Carson City tied up emergency personnel, so the people of Walker were left to their own devices, and the hard work of the handful of highway patrol officers and county sheriffs in the area. Eventually a helicopter was brought in to rescue some stranded motorists. There weren't any television cameras recording the drama; they were too busy elsewhere.

I was not there to see the worst of it. I knew from the news reports that terrible things must be happening up there. It was about two days before we found a route into town, and the property was a mess. Against all odds, the house on the river survived the onslaught. Knowing the odds of a flood, my relatives had built an earthen berm around the house, almost like a fortress wall. The river had flowed full force into the berm, and was in the process of undercutting the foundation when a large pine got wedged into the opening, diverting the flow to the south (and eventually burying their truck in the mud). Their doors even held back the mud, and they might have been ok...except for the cat-door. Mud and silt flooded into the house to a depth of a foot or two. There would be a lot of cleaning up to do in coming months. Thankfully the relatives had flood insurance.

The following month had only one cold storm, and that February was one of the driest on record. No one minded. Clean up went on, and eventually the Army Corps of Engineers decided they wanted to put the river back where it used to be. This was an impressive process to watch. They had really big bulldozers to clear the old channel of debris, and I was sitting on the riverbank the day they made the cut that diverted the prodigal river back where it was supposed to be. We cheered as the river came back home...

After that flood, my relatives decided they had other priorities for their lives and sold the house. The new buyer found out that the legal floodplain level was now two feet higher than it had once been, and the house was now out of compliance. He solved the problem by taking the entire house and lifting it up eight feet and inserting a garage and basement underneath. I didn't recognize it the next time I came through town.

Do you have a good flood story?

Wednesday, October 21, 2009

Senator McCain joins Governor Jindal in Geologic Ignorance

Senator (and would-have-been president) John McCain twitters today that the #1 most egregious example of government waste is the expenditure of $325,000 "to study seismic activity in Memphis, TN". This statement echoes Louisiana Governor Bobby Jindal's statement last fall that the government was wasting $140 million on something called volcano monitoring.

Maybe McCain doesn't like that the money is spent under the auspices of the Department of Homeland Security, but the statement does reveal some appalling ignorance. The region around Memphis (and New Madrid, MO) was shaken by three massive earthquakes in 1811-12. It is one of the more dangerous seismic zones in the country that isn't named California, Alaska or Washington. Unfortunately, it is also one of the most enigmatic, being in the interior of a lithospheric plate, meaning there are no obvious reasons for earthquakes to be happening there. What is also not well-understood is the recurrence interval; when will the next large earthquakes strike? We don't know, hence the justification for studying "seismic activity".

I dunno. It seems to me that "homeland security" means something along the lines of keeping the populace safe from harm, whether the cause is "terrorism", or from natural disasters. I don't usually blog politics, but this is not smart politics.

Tuesday, October 20, 2009

The Airliner Chronicles: Crater Lake

In honor of my friends and colleagues who are gathered together in Portland for GSA this week, I'm sending out a new Airliner Chronicle photo of an Oregon volcano (wish I was there with you all!).

Crater Lake is one of America's crown jewels, a feature so unique that it was one of the earliest National Parks to be established, in 1902. Despite the beauty and unique nature that led to the protection of the lake, the actual origin of the "crater" was not completely understood. Early assumptions were that the volcano had blown out the summit in a titanic explosion (though the local native Americans knew better; their ancestors saw it happen). It wasn't, exactly.

Crater Lake began as a composite volcano, an edifice of several overlapping cones that reached an elevation of between 10,000-11,000 feet, perhaps similar to the Three Sisters a bit farther to the north. The magma chamber was evolving in late Pleistocene time to a more silicic (and more explosive) condition. About 7,900 years ago, a large plug dome, Llao Rock erupted on the northeast flank of the volcano, heralding trouble. Two hundred years later, a massive single vent ash eruption shook the mountain. The ash cloud reached tens of miles into the sky and the entire summit region of the volcano destabilized and began to collapse inward. Vast amounts of hot ash burst out of the flanks of the mountain, burying local valleys 300 feet deep. By the time the eruption subsided, the entire summit region of the volcano, an area five to six miles across, had collapsed thousands of feet into the depleted magma chamber, forming a caldera. It had been the largest eruption in the Cascades within the last million years, releasing some 12 cubic miles of ash into the atmosphere, which covered a vast area of the western United States, even into British Columbia.

In the decades and centuries that followed, water began to accumulate in the basin, eventually filling it to a depth of 1,945 feet, the deepest lake in the United States, and the seventh deepest in the world. Post-collapse volcanism built several cones within the caldera, including Wizard Island, an andesite cinder cone that peeks about the water surface on the west side of the lake.

My picture was taken in the last moments of a miserable nine hour flight from Germany to San Francisco in 2007. My choice of black and white may seem...antiquated, but the forest was almost as blue as the lake in the original picture, so I took out the color and upped the contrast to bring out the lake a bit more.

Saturday, October 17, 2009

The Airliner Chronicles: My First Blog Series

I've decided to tabulate one more series that I produced in my first year of blogging: the Airliner Chronicles. As I noted in the first blog of the series:

"What a perfect situation for photographic excellence: small dirty scratched windows, absolutely no control over the route, inclement weather conditions, and jetwash distortions. Taking pictures from a commercial airliner is an exercise in futility. And yet, who of the geologists among you has been able to resist the impulse to try to take decent pictures of the geologic phenomena below you on those long, boring flights?"
Air routes take you over terrain that you, and practically no one else in the world, can ever visit and the view is unique. The first picture of the series was one of the massive glaciers along the coast of Greenland, a place I would dearly love to see up close, but I just don't see it happening in the present circumstances of my life. So here they are, in the order that they originally appeared:

Picture of the Day - The Airliner Chronicles: A two minute break in the clouds on my first international flight allowed me a very brief glance at Greenland's glaciers

Picture of the Day - The Airliner Chronicles Part 2: A twilight flight out of Seattle yields a ghostly look at Mt. Rainier (click on the photo to enlarge it; I love the details revealed on the glaciers)

Picture of the Day: The Airliner Chronicles, Part 3: A look at Mt. St. Helens and the Toutle River Valley, site of the devastating 1980 debris avalanche and ash eruption.

Picture of the Day - The Airliner Chronicles Part 4 : Mt. Hood, one of the Cascades volcanoes and the tallest mountain in the state of Oregon

Picture of the Day - The Airliner Chronicles Part 5 : Mima Mounds in Washington. A marvelous geological mystery!

Picture of the Day - The Airliner Chronicles Part 6 : The Three Sisters, Cascade Volcanoes in Oregon

Picture of the Day - The Airliner Chronicles Part 7 : Revisiting Mt. Rainier, but in the daytime on a wonderfully clear summer day (again, the best view is to enlarge the photo by clicking on it)

Picture of the Day - The Airliner Chronicles Part 8 : The theme changed to glacial landscapes in Canada and Greenland. This photo may have been near Baffin Island, but good luck finding it on GoogleEarth

Picture of the Day - The Airliner Chronicles Part 9 : Breaking pack ice in the vicinity of Baffin Island, Canada

Picture of the Day - The Airliner Chronicles Part 10 : Kettles and deranged streams in northern Canada

Picture of the Day - The Airliner Chronicles Part 11 : A mystery picture!

Airliner Chronicles Follow-Up : A ground-level clue to the previous photo

We have a Winner! An explanation of the mystery shot: the photo shows a massive debris avalanche that destroyed a previous incarnation of the Mt. Shasta composite cone in northern California (kind of a nice view of Mt. Shasta, too)

Picture of the Day - The Airliner Chronicles Part 12 : A picture of one one of the more mysterious corners of Washington state, and one of the great detective stories of geological research, the Channeled Scablands

Picture of the Day - The Airliner Chronicles Another view of the remnants of one of the great floods of earth history: the Channeled Scablands

Picture of the Day - The Airliner Chronicles A flight over the Overthrust Belt near Banff National Park in Alberta, Canada

Picture of the Day - The Airliner Chronicles Back to Greenland, where a crevasse field generated a nice web discussion

Picture of the Day - The Airliner Chronicles : Some beautiful valley glaciers and a fjord in Greenland

The Return of the Airliner Chronicles: the Biggest Mountains on the Planet After a long hiatus I came back to the chronicles with a series of Hawaii shots. This one included the giant shields of the Big Island, and Diamond Head on Oahu

The Return of the Airliner Chronicles: the Biggest Mountains on the Planet, part 2 : A pair of photos showing some details of Mauna Kea on the Big Island of Hawaii

The Return of the Airliner Chronicles: When the Giants Begin to Die : A look at the summit of Haleakala on the Hawaiian island of Maui. It is a giant shield approaching the final stages of activity, miles from the hot spot on which it originated

I've got more in the photo files, so the Chronicles may make some future appearances. I'll update this post if it happens. Hope you enjoyed the journey!

Today's aerial is a close shot of Lassen Peak in northern California. Lassen was the most recent California volcano to erupt, with activity from 1914 to 1917 (the region is still a "hotbed" of geothermal activity). This extraordinarily large dacite plug dome is protected within the boundaries of Lassen Volcanic National Park. The main park highway can be seen snaking along the lower left hand side of the picture.

New Additions:

The Airliner Chronicles: Crater Lake : in honor of my colleagues at GSA this week.

The Return of the Airliner Chronicles: The San Andreas Fault in San Francisco. I finally get a good perspective on the fault zone!

The San Andreas fault in Southern California and the San Gabriel Mountains

Friday, October 16, 2009

Has it Been That Long Already? Loma Prieta Earthquake 20 Years Ago Today

It's been quite a week, this year's Earth Science Week, starting with a record-breaking storm in California, suffering cuts in the geology field studies program at our school, and the 20-year anniversary of the Loma Prieta Earthquake on October 17. I hate to be missing the GSA meeting starting this week in Portland; many members of the geoblogosphere will be there.

Andrew Alden at About.com: Geology and the Berkeley Seismological Laboratory are asking for our stories about the quake. In 1989 I was a brand-new instructor at Modesto Junior College, in my third semester. I taught classes in the old 1950's-era Science Building on our east campus, up on the second floor. I had all the modern teaching technology; there was a chalkboard, and two television monitors hung from the ceiling for showing those newfangled "videotape cassettes". The monitors also served as my decidedly low-tech seismometers. They shook noticeably during the smallest of earthquakes (most memorably during a class test on earthquakes; no one but me even noticed).

On October 17th at 5:04 PM, my physical geology laboratory had just finished and almost everyone had gone home to watch the World Series. A couple of students were helping me (it was Maureen and Sonny; funny how I remember the names of the first students I had better than the ones I had last semester). We were 100 kilometers from the epicenter, so when the seismic waves started to shake our building, the movement was a strong rolling motion instead of sharp vibrations. We looked at swaying TV monitors, and commented that it was an earthquake. It was a most scholarly discussion, actually. We realized the shaking was not stopping, and we thought we could sense the direction of the quake as well. We started to guess where it might be happening, but when the shaking reached the 40 second mark (the energy was spreading out, it lasted only 10 seconds or so near the epicenter), we realized it was a major event, and that fatalities were probably occurring (and unfortunately we were right). The deodar trees out the window were whipping back and forth as if they were in a high wind. The strangest part for me was the unconscious decision I was making as the shaking progressed. Despite having a quiet scholarly discussion, my body was moving from the front of the podium to the back, where there was a nice solid space to hide under. I would have dived under if the quake had lasted any longer.

In hindsight, I should have been a bit more aggressive about taking shelter under the desk. An analysis of our building a year or two later revealed an architectural weakness that suggested the building could collapse if the seismic waves hit it from a particular direction. A seismic retrofit a decade later included some massive shear walls in the lab I taught in.

Meanwhile, at the city library, my children were making me proud. At the time of the quake, there were huge sailing ship models on display, in some cases right on top of the book stacks. The stacks were not reinforced or braced, so there was a real potential for injuries if the quake was strong enough to knock those stacks over. I was told that most people were just standing there watching the bookstacks swaying, but my kids, my well-trained and intelligent kids were the only people in the room to take shelter under the sturdy study tables. Luckily, as I said before, we were on the fringes of the effects of the earthquake and no one was hurt.

The Loma Prieta earthquake, a magnitude 6.9 event at a depth of 11 miles, was a tragedy: 63 people died, and 3,700 were injured. The Bay Area was in chaos for days and months passed before life got back to normal. We were on the fringes, so instead of pain and suffering, we had a profound learning experience that was remembered by my students for the next decade and a half. But it has been 20 years now, and many of my students weren't born when the quake happened. Few of them have felt a quake at all. The large quakes like Loma Prieta and Northridge are ancient history, and there is less of that innate knowledge of what they should do when one hits. Few admit to having any kind of emergency kits at home, and they have no plan for what to do when the next big one hits.

Fault studies across California make it clear that more big tremors are coming, almost surely within the next decade or two. We educators must keep these past events alive in the minds of our students so they will be ready for these events when they come.

Losing Field Studies: Budget Crisis Continues in California

The continuing recession (and here in the Central Valley of California it is a depression) and the California state budget crisis is hitting our school hard. Got word today that our summer field studies program, a two-week field studies program that takes our students all over the American west and to international destinations, has been eliminated for 2010 and probably for 2011 as well. It is a truly unfortunate development, because aside from the instructor's salary, the program was funded by the students. It didn't really cost the school much, but the college has decided to focus on the core classes for each discipline, and running the field studies would mean one less math or English class on the schedule.

I'm not complaining exactly, because I still have a job, and a great many people have it far, far worse (although I did lose one teaching job this year already). I am simply saddened that our program is losing one of the best tools we have for training geology and teaching majors the core principles of the geosciences. It's one thing to describle rock types on a chalk board or in a box in the lab, and quite another to pick up rocks and minerals in the context of where they are found in nature. Teachers who have seen the things they talk about, whether volcanoes, faults, fossils, glaciers or whatever, will be better teachers. Geologists without field experiences are at a severe disadvantage in academic and employment settings.

For the time being, some of our more local field studies will go on in the fall and spring semesters, but I fear what is coming in the next year. Even if the economy improves it may be years before the state budget improves to an extent that will help the community college system. That somehow seems wrong, because it is the community colleges that are at the forefront of retraining workers during times of economic upheaval. But we are closing our doors to new students these days.

Wednesday, October 14, 2009

Storm's Aftermath

My program of allowing my trees to "self-prune" worked like a charm in yesterday's Pacific storm, which combined a typhoon with the jet stream. Rainfall records were set all over California, including 21.22 inches in 24 hours at a recording station south of Big Sur. Winds in my neighborhood hit 45-50 mph, and branches and trees came down (newspaper reports are calling it the worst windstorm in 10 years). If I was grouching at all about having to get up and cut up fallen branches in my yard (above), I was immediately cured when I walked around my corner and saw what happened to my neighbor...


Tuesday, October 13, 2009

What a Way to Introduce Earth Science Week!


Well, we've kicked off Earth Science Week, and the theme of "Understanding Climate" in California with a whopper of a storm, the result of of the remnants of a super-typhoon in the Pacific meeting up with the strong jet stream. It slammed us pretty hard. In my own corner of the world in the Central Valley we had record rainfall for this date in October, breaking a fifty-year-old record (1.57 inches in Modesto, old record 0.97 inches) with wind gusts reaching 47 mph. My backyard rain gauge recorded even more, 1.90 inches, the second highest one-day rainfall total I have recorded in eighteen years. Trees and large branches are down all over town (including in my front yard), and the power has gone out several times over the course of the day. We are the arid spot of northern California; other places got a lot more: San Francisco Airport, 2.64 inches; Sacramento, 3.04 inches; Yosemite 3.43 inches. The big numbers are coming out of the Coast Ranges, which rise out of the surf along Big Sur and Santa Cruz to elevations of more than 4,000 feet: Venado 5.68 inches, Ben Lomond 10.58 inches, Three Peaks 14.30 inches, and at a recording station called Mining Ridge, just south of Big Sur, 19.45 inches (real-time data from the California Department of Water Resources Rainfall Maps)! I can barely imagine this kind of water coming from the sky.

It's probably a good moment to mention that a single day of incredible storminess is not "climate", it's "weather". Climate refers to the long-term pattern of precipitation and temperature that defines a region. A single storm does not have a direct bearing on our understanding of the nature and pace of climate change, but a pattern of increasing intensity or frequency over a period of years will shed some light on the issue. Especially if it has been predicted by climate modeling.

Sunday, October 11, 2009

The World is Going to End in 2012! Uh...Random Thoughts for Earth Science Week


"But most archaeologists, astronomers and Maya say the only thing likely to hit Earth is a meteor shower of New Age philosophy, pop astronomy, Internet doomsday rumors and TV specials..."

This was my second favorite quote from this story on the Mayan calendar ending in 2012. My favorite is that of a Mayan Indian elder, Apolinario Chile Pixtun: "I came back from England last year and, man, they had me fed up with this stuff."

The problem, of course is that someone gets it in their head that a Nostrodamus prediction, or some scriptural prophecy is about to come true, and there are always armies of gullible people anxious to lap it up. There is a web site, the Rapture Index, that rates world events in reference to the end of days. You can find it yourself, but if you are curious, today's rating is 164, which in their terms, means "fasten your seatbelt". I watch this kind of thinking, and shake my head.

It is a lot easier to think "I am one of the elected few" and that I won't have to deal with hard problems because I'm going to be taken away, and those "left behind" can just suffer. Or that it will be over with quickly, whatever the disaster is to be, whether it is California falling into the sea in one massive earthquake (and NBC, you didn't help things at all with that execrable movie "10 1/2"), or massive asteroid impacts that destroy all life on the planet (unless Bruce Willis can blow up an atomic bomb "exactly 100 meters" down or something like that). Unfortunately a recent climate change movie (Day After Tomorrow) had to take a granule of truth and speed it up by a factor of thousands so they could destroy New York in a massive immediate ice age (although I liked the irony in the movie of having millions of Americans trying to get into Mexico).

The sad truth is that there are really big problems we face as a species, and they are not getting the attention they must have. The problems are interrelated: the end of the oil economy, climate change, soil erosion and drought, rising sea level. The people who have the real power in the world are invested in the status quo, and in most cases have little or no understanding of the science involved in the dire predictions for the next few decades. In fact, they can see no farther than the next election, so they are invested in making sure we don't think about these things. Nobody wants to elect a "downer" politician who calls for national sacrifice. Just ask Jimmy Carter, who made one of the finest speeches on what was needed to face the energy future in 1977, and who was repudiated at the polls in 1979. The men who beat him set us back decades in energy independence. We ended up fighting a war over oil in 1990-91, and oil factored in the war we are mired in now. And we import more than ever. And the seas rise, the droughts intensify, and we choose to worry more about Michael Jackson, and toilet flushing internet cats. Because our problems are hard.

And we have the embarrassment of having a sitting U.S. senator, James Inhofe, who has in all likelihood never sat through a science course in his life, heading to the Climate Change Conference in Copenhagen in December to tell several thousand climatologists that they are all wrong about climate change. Scientific debate is critically important; putting ideological values above science is appalling.

And so I begin Earth Science Week with a certain feeling of despair. But it is only temporary. What can a few thousand teachers and educators do in the face of intractable and difficult problems? We can do a lot, actually. Education is a powerful weapon! Education drove the movement that resulted in the National Park System. Education drove the environmental movement in the 1970's that cleaned our air and water. Education resulted in the effort to reduce freon in the atmosphere. Education is making Californians safer in the face of future large earthquakes. So go for it! With all the knowledge you can share. We need it.

And if I am wrong, and the world ends in 2012, wherever we end up, I invite you to say "I told you so".

Prius and Honda, Ichthyosaurs and Dolphins, and Mary Anning

What do the Toyota and Honda gas-electric hybrids have to do with Ichthyosaurs and Dolphins? Devilstower offers up a nice discussion of convergent evolution this week over at DailyKos. The post explores why Australia has an ecosystem of marsupials who bear a striking resemblance to placental animals in other places, why bats and pterosaurs are so similar, and why sharks, dolphins and Jurassic sea-going reptiles called ichthyosaurs look like closely related animals when they are not. It also provides a decent explanation about why Charles Darwin and Alfred Wallace both hit upon the idea of natural selection as a driving force behind evolution, and how the idea was facilitated by an early 1800's fossil collecter named Mary Anning. It's worth checking out! The ichthyosaur display in the picture is at the London Natural History Museum. It was an impressive wall of fossils, of which this is only a small part.

It's Earth Science week, by the way! What will you be doing this week to promote an understanding of climate change?


Friday, October 9, 2009

Under the Volcano and Into the Abyss: Yosemite National Park



Yosemite National Park is the oldest "national" park in the United States, having been established by Congress and Abraham Lincoln in the midst of the Civil War as a protected reserve deeded to California. It became an official national park in 1890, third after Yellowstone and Sequoia. I did a short blog series (boog? bleeries?) on some of the less familiar sights that one-time visitors might miss if they spend all their time looking at Yosemite Falls or Half Dome. I recalled the series while discussing America's relationship to the national park system in the aftermath of the wonderful Ken Burns documentary "The National Parks: America's Greatest Idea". I have them (semi) organized below in the order that they appeared. I've also included a flurry of posts on some of the rock falls in the last year. If you are ever headed out to Yosemite, check out the NAGT geologic road guide to Yosemite Valley and the western Sierra foothills (the extended wood-pulp version can be ordered here).

Photo of the Day - Feeling Crushed? : this series started far from Yosemite, but rocks in the Coast Ranges are very much part of the story. Sierra granites originate from subduction of crust and subsequent melting of these rocks to form magma. We take a drive into the crust that would make Ms. Frizzle jealous

Journey to the Center of the Earth (well, the mantle at least) A brief look at chrome and mercury mining in the Coast Ranges, in the subduction zone rocks

Continuing Journey in the Earth - Taking the Time Machine When granites were forming under the future Sierra Nevada, dinosaurs and sea-going reptiles prowled the ancient land surfaces

Standing Underneath Volcanoes We arrive at Yosemite Valley and I describe the familiar scene from the Tunnel View, and explain the odd title

Touring the Underside of the Volcanoes, Part 2 How easy is it to visit the underside of a volcano? We find out, and what enclaves are in this post

Under the Volcano: Changing the Emphasis Taking a closer look at the Cathedral Rocks and the El Capitan granite that forms the impressive cliffs

Under the Volcano: Changing the Emphasis -Part 2 Another less familiar cliff is Sentinel Rock (see the second picture above), and the Sentinel granodiorite of which it is composed

Under the Volcano: Changing the Emphasis -Part 3 One of the unknown waterfalls in Yosemite is the rarely seen Sentinel Falls, on the south side of the valley across from Yosemite Falls

Exploring Yosemite, continued and the Rock of the Day A brief foray west of the park on a beautiful spring day, and a look at some of the older metamorphic rocks

Under the Volcano: Changing the Emphasis -Part 4 Who's heard of Lehamite Falls? Many park visitors ignore them, for they are overshadowed by nearby Yosemite Falls

Yosemite Falls: The Spectacle that Almost Wasn't Yosemite Falls are actually an aberration! They were once far more like Lehamite Falls in the previous post...I explain why

Under the Volcano: Changing the Emphasis -Part 5 A look at the Lost Arrow

Under the Volcano: Changing the Emphasis -Part 6 The highest unbroken waterfall in Yosemite is not named Yosemite! I describe it in this post

Under the Volcano: Changing the Emphasis -Part 7 Another little-known fall, the Royal Arch Cascades, behind the Ahwahnee Lodge

Under the Volcano: Changing the Emphasis -Part 8 Silver Strand Falls, another unknown waterfall

Under the Volcano: Changing the Emphasis -Part 9 Sometimes the familiar sights become transformed by different timing. Yosemite Falls at night, one of the few times we ever had the valley to ourselves

Staring into the Abyss - Yosemite as you (maybe) have never seen it We leave the valley floor and take in the view from the edge of the abyss at Taft Point

Staring into the Abyss #2 - Yosemite as you (maybe) have never seen it The Three Brothers from the rim, and Yosemite's largest historically recorded rockfall

Staring into the Abyss #3 - Yosemite as you (maybe) have never seen it Looking west from Taft Point towards the Cathedral Rocks, and what happened to Yosemite's meadows?

Staring into the Abyss #4 - Yosemite as you (maybe) have never seen it (and my 100th Post!) There are many domes in the vicinity of Yosemite Valley, and most did not form because of glaciation. A discussion of North Dome and Basket Dome, from Glacier Point

Staring up out of the Abyss: Check out this fire in Yosemite I link to one of the most extraordinary pictures I've ever seen of Yosemite. A fire was burning on the north rim, dropping embers into the valley. Spectacular!

Staring into the Abyss #5 - Yosemite as you (maybe) have never seen it Nevada and Vernal Falls from the Glacier Point area

Taking the High Ground: Yosemite as you (maybe) haven't seen it Climbing Sentinel Dome. A bit shorter than Half Dome, and a lot easier to climb!

Revisiting Yosemite Several weeks passed, and I made a few last posts before embarking on my journey through the Colorado Plateau. Yosemite Falls on a very windy day

An Alternate View of Upper Yosemite Falls My photo of Upper Yosemite Falls from an odd angle.

Is This the Most Beautiful Tree in the World? Several months passed, and several posts continued the tour of the valley floor; my favorite oak tree started a mini-meme

More Beautiful Trees... The tree meme grows...

Even More Beautiful Trees, and a Sequoia Story ...and grows some more!

How It Was: Yosemite Valley Yesterday... I visit the valley on a rainy November day, and watch Yosemite Falls go from dry to booming in a few short hours

Rocks fall in Yosemite? I had no idea that could happen! A discussion of rock falls in the valley; there was a lot going on in the valley in 2008-09!

Rocks fall in Yosemite: Park Service closes 1/3 of Curry Village More rock falls

During a Drought, What Do You Think About? In the midst of one of the worst drought years in decades, I ruminate on the incredible 1997 floods in Yosemite Valley and downstream

An Extraordinary Picture (at least for us Central Valley denizens) We find that Half Dome is visible from the Central Valley (on those rare clear days, anyway)

How it was: Yosemite Valley on a Saturday in April A springtime trip to the valley in the aftermath of a major rockfall. Several posts followed...

First Look: Ahwiyah Rock Fall in Yosemite A first look at the Ahwiyah Rock Fall from near Half Dome. The view of Yosemite changes forever!

Another Look: The Ahwiyah Slide in Yosemite Got as close as I could to the new rock fall (don't people usually run the other way?)

A Final Look (for now): The Ahwiyah Point Slide in Yosemite The dust settles...

The Ahwiyah Point Rockfall: the View I Wish I Had The National Park Service checks in with some great photos of the rockfall

Ahwiyah Point Rock Fall Update: Before and After Photos Doug Nelson provides a great view of the rockfall from Glacier Point

Geologic Change in Yosemite: Remembering the Happy Isles Slide of 1996 A look at the big slide behind Happy Isles...

Another Rock Fall in Yosemite ...and the next day, another fall takes place!

Ollie Hopnoodle's Haven of Bliss and America's Greatest Idea And we arrive at the most recent post on my favorite park.

I intend to continue some photo-essays on Yosemite National Park. I'll update this post as they appear. If you take the time to check them out, I thank you and hope you enjoy the series!

Thursday, October 8, 2009

Ollie Hopnoodle's Haven of Bliss and America's Greatest Idea



A favorite seasonal tradition for many people is a viewing of the movie "A Christmas Story", the adventure of Ralphie and his quest for a Red Ryder BB gun. Most people are unaware of a second film in the adventures of Ralphie that came out as a 1988 Disney TV movie: "Ollie Hopnoodle's Haven of Bliss". Jean Shepherd once again narrated the adventures based on his childhood in 1940's Indiana, with Ralphie's first summer job, and the family's traditional yearly vacation to a lake in Michigan, the Haven of Bliss resort. It has yet to be released on DVD, but if you get a chance, check it out. It's hilarious, and even touching at times.

Ollie Hopnoodle came to mind last week when I was watching Ken Burn's wonderful documentary "The National Parks: America's Greatest Idea". As America's relationship to the national park system evolved, families who hit the road in the summertime began to "collect" parks in a sense, visiting as many as they could over the years. It could be a tremendous undertaking, given that most Americans lived in the east, and most of the parks were in far-flung locations in the west. Others come back to parks they love the most, year after year, in much the same way that Ralphie's family returned to Haven of Bliss. In another wonderful park movie, "Yosemite: Fate of Heaven", a family is interviewed about their yearly sojourn to the tent cabins of Curry Village. They have been there so many times that they can describe the relative merits of the view from one cabin over another.

This was on my mind last weekend as I made my estimated 75th trip to Yosemite National Park. I was thinking of the relative merits of learning a place in depth, or of seeing as many of the wonderful places of the world as one can with the limited time we all have for such ventures (the idea of seeing as many places as possible resulted in a fairly wild geoblogosphere meme and accretionary wedge last year). I tend towards the "collector of many places" school; I want to see as much of the world as I can before I'm done. Yet I also feel a certain frustration when I am on a once-in-a-lifetime tour: trying to take the pictures of things I may see only once, without the chance to linger and get to know them well.

In contrast, I live only a two hour drive from Yosemite National Park, and believe me, I never take it for granted. It is a true gift to be able to suddenly decide to run up to the park for a day or a weekend. We enjoy the sights everyone else seeks out, but we spend part of every trip trying to find something new, something we have never seen before. Sometimes that takes the form of pulling out the camera at a place that I would guess has been photographed 100 million times or more, and finding some new angle, some new feature that doesn't show up in the travel magazines. Other times it means hiking a new trail, or following a new road. It's not on the park map, and not widely known, but there is a perfectly accessible old fire lookout in the west part of the park that commands an incredible view from the Central Valley to the crest of the Sierra Nevada.

It boils down to the idea that one life just isn't enough. Every trip not taken is a loss and a waste, whether it is to a famous park half-way around the world, or a familiar non-descript lake in the midwest, hidden deep in a beautiful forest. Get out and enjoy your world, and take your kids with you! Electronic games can wait until you are sitting in the back row at school or stuck in another department meeting.

What do you think?

Today's pictures seem familiar enough, but I had never seen Half Dome in such stormy weather conditions, and the valley looks different from Tunnel View if you climb the hill and use some vegetation for framing.

Update: fellow geoblogger Callan Bentley was in Yosemite the same weekend as I was, but we ended passing each other on the highway! His photojournal can be found here.

Wednesday, October 7, 2009

Of Vooks and Blooks

I offer my apologies in advance for what follows...

I thought I heard a discussion of some weird new kind of "vook" on public radio the other day, and finally ran across a written account of video-book hybrids in this article in Salon.com. I can see the usefulness in such a monster if some kind of complicated process is being taught, but I am less enamoured of the idea if it is going to be a low-cost drama production. I get lots of that on the cable channels.

It reminded me of a discussion I had the other day with someone who doesn't want to be associated with the writing disaster that follows. We were talking about the nomenclature for the project I just finished on the Colorado Plateau. Over a year's time, the series of blogs had grown into a narrative with the length (if not the style) of a small book. What should such a thing be called?

We immediately thought of "blook" and congratulated ourselves on our creativity and originality but a quick google search confirmed the that term has existed since at least 2002. Oh well. Just the same we realized that people who write blooks would have to be called "blookers", and if the authors are German women, they would be "Frau Blookers" (frenzied neighing of horses breaks out*).

Our second choice for the name of a blog-book hybrid would be a "boog". I liked it, but a google search revealed that a boog had all kinds of dark and gross meanings related to nostrils and drugs. So that won't work so well, but so many things could have been right about the word. When we said we needed to "boogie", folks would think we were really cool and all, and not going home to chew on Cheetos and stare at a computer screen. The problem with "boogs", books written as a series of blog posts, is the lack of continuity and style. Such projects need the help of an editor or even an editorial board, a "boogie-board" as it were.

Maybe an interesting idea. It ultimately can't work though, because the authors of boogs would of course have to be called..."boogers".

Ok, back to geology...

*If you don't know this movie reference, you have to go study Mel Brooks and satires of old monster movies

Sunday, October 4, 2009

Do Big Earthquakes Cause Tremors Elsewhere?



With the spate of large earthquakes worldwide, some people have asked if large earthquakes can set off smaller earthquakes elsewhere. In short, the answer is yes, but the big earthquakes don't make other earthquakes; they may help trigger earthquakes in places where stresses are close to the breaking point anyway. These smaller quakes usually occur within a few hours of a major tremor. But there are some odd complications that are now being recognized.

Some new research, reported in NatureNews, suggests that large distant quakes can weaken other fault zones and cause activity months later. This assertion is supported by the fact that the period of 2005-2007 following the devastating magnitude 9 Sumatra-Andaman quake (the tsunami killed nearly a quarter of a million people) had the largest number of large earthquakes than any comparable period since the early 1900's.

The abstract for the research article can be found here (the entire article requires a fee). The full article: Taira, T., Silver, P. G., Niu, F. & Nadeau, R. M. (2009). Remote triggering of fault-strength changes on the San Andreas fault at Parkfield, Nature 461, 636-639.

The photos today show the San Andreas fault on the Carrizo Plains south of Parkfield, and the Landers fault in the Mojave Desert. The 1992 quake on the Landers fault (mag. 7.3) set off tremors at Parkfield months later.

Saturday, October 3, 2009

The Keeler Earthquake Swarm




The U.S. Geological Survey (and my department seismometer) is reporting a vigorous swarm of small and moderate quakes about seven miles south of Keeler, California. The swarm has included two 5+ magnitude shocks, and at least 22 events between magnitude 3 and 5. Smaller events number in the hundreds.

Keeler is a small village along the former shoreline of Owens Lake at the south end of the Owens Valley. The pictures provide some context: the Owens Valley is the first of the Basin and Range Province grabens east of the Sierra Nevada, with the White/Inyo Mountains forming the east side. The top picture shows the Sierra crest, including the peaks in the vicinity of Mt. Whitney, the tallest mountain in the lower 48 states. The bouldery Alabama Hills and the town of Lone Pine are in the bottom of the valley, center-left, and the Inyo Mountains form the right-side skyline. With the valley floor at 4,000 feet and the surrounding mountains ranging up to 14,000 feet, the valley is twice as deep as the Grand Canyon. Although the Owens River flows through the valley (sort of), it is a faulted graben, not a river-cut valley.

The second photo (from the same vantage point on the Cottonwood Lakes road) shows Owens Lake, the south end of the Inyo Mountains, and the domes and craters of the Coso Mountains Volcanic Field on the right. Owens Lake is one of the pluvial ice age lakes that formed when glacial meltwater from Sierra glaciers drained into the desert. Unlike most of the dry lakes across the Basin and Range, Owens Lake actually had water until the 1920's. Los Angeles diverted the streams that flowed into the lake and sent the water south through a massive aqueduct to the growing city. Keeler was a depot for silver and lead being mined high in the Inyo Mountains at the Cerro Gordo Mine in the late 1800's. Ores were carried down to the town by aerial tramway, and then loaded on a steamship to cross the lake to railroad station.

The epicenters of the swarm would be in about the center of the second photo. Why are there quakes here? As noted before, the entire valley is a fault graben, so quakes are not at all unusual. One of California's largest historical earthquakes, the 1872 Lone Pine earthquake (mag. 7.8 or so) happened just north of here. Swarms have happened in the local region in the past, including some magnitude 5 events in the 1990's.

The Coso Volcanic Field lies just to the south. A collection of basalt flows and rhyolite domes, it was last active around 40,000 years ago, though a few cones may be younger.

UPDATE: not of the earthquake, but of the Coso Volcanic Field. It might be an actively forming metamorphic core complex! In 2 to 4 million years, the detachment surface may be exposed. I always enjoy learning something I didn't know before...

UPDATE #2: Loads of info on the quake swarm on the SCSN Pages here. The largest quakes are showing right lateral focal plane solutions, which is in keeping with the regional structural trends on the Owens Valley floor. This strongly suggests to me that the quakes are tectonic and not related to any kind of volcanic activity (but I'm not claiming expertise in the matter).

UPDATE #3: Reports of sand boils on the Owens Lakebed (see the comments) have been confirmed by the SCSN and USGS office in Pasadena (personal communications, no link).

UPDATE #4: See down in the comments for a correction on the history of Keeler from Roger Vargo, who is the sometimes caretaker at Cerro Gordo. Thanks for the correction, I was operating off the memory of a field trip from 25 years ago.