Wednesday, February 29, 2012

Strangers in a Strange Land: Discerning the Story in the Rocks at Red Rocks

In the last post, we were introduced to the basic rules of stratigraphy as they stood exposed in the spectacular cliff faces of Red Rock Canyon State Park in California's Mojave Desert. A classroom chalk board can only provide a cartoon of these concepts, so there is nothing quite like being there and laying your hands on these records of the Earth's past. We were on the road with 30 community college students, most of whom were seeing this landscape for the first time. After an introduction to the stratigraphic principles of superposition, original horizontality, lateral continuity, and cross-cutting relationships, I sent the students forth to test their newly acquired knowledge against the cliffs above. We weren't quite to the point where we could do geologic mapping, but I provided them with an outlined photo of the scene (below) and asked them to describe the rocks, and identify any structures.
This is one of the finest moments a teacher gets to have. I wasn't teaching at all; my students were teaching themselves. They were crawling up and down the slopes, taking notes, and discussing what they were seeing. OK, it's true there was no cell phone service, so what else were they gonna do?
The layers were readily labeled on the basis of color alone, and most of the students developed some version of the picture below (click to enlarge):
I climbed up the slopes to have a closer look at some the exposures. What happened here 8-12 million years ago? The red and brown layers (A, C, and D) proved to be arkosic sandstones, the kind of thing one might find in river channels and alluvial fans in a region of relatively high relief (lots of rapid erosion). Some of the finer-grained brown sediments formed in river floodplains. These rocks had clearly formed on land.
The white layers (B) with puffy deposits that kind of looked like ground hamburger were ash deposits, evidence of regional volcanic activity. The ancient environment here was beginning to look a little bit dangerous!
The upper cliffs and slopes (layer F), proved to be evidence of the greatest geological violence possible, a rhyolitic tuff breccia. The rock formed when hot ash rolled over the landscape, picking up gravel and debris and incorporating the material in the nearly molten tuff deposit. This was no place to be hanging about...but plenty of animals did. The layers of the Dove Springs Formation are a treasure trove of Miocene fossils, one of richest beds found in California (or pretty much anywhere, really).
The animals found in the sedimentary sequences here include include extinct elephants, rhinos, three-toed horses, giraffe-like camels, saber-toothed cats, and bone-crushing dogs as well as smaller animals like ancestral skunks, martens, alligator lizards, rodents, and shrews. (follow the links to descriptions of each type of animal on the Los Angeles Natural History Museum website).

Faults in a cartoon drawing on a chalkboard are a lot easier to see than most faults in the real world. A number of the students noticed how the layers ended and identified the fault that caused them to be offset (see the arrows in the diagram above). I headed up to take a closer look at the fault surface...because I think everyone should know their faults...
We only had a few precious days to see as much as possible on this trip, so we couldn't spend as much time at Red Rock Canyon as we would have liked. A fair number of geology programs do mapping exercises here, spending several days on site. It sounds like fun...if it isn't too hot. It was time for us to move on, so we loaded up the vans and drove north on Highway 14 towards our next destination at the south end of the Owens Valley. That will be part of the next post.

If postings seem sparse in the coming week, it would be because we are about to embark on part two of our Strangers in a Strange Land journey: an exploration of the Mojave Scenic Preserve in the desert south of Death Valley. We're attending the spring meeting of the Far Western Section of the National Association of Geoscience Teachers at the Desert Research Center at Zzyzx. Hope to see a few of you there!

Sunday, February 26, 2012

Strangers in a Strange Land: What stories can the stones tell?

What does a cartoon tell us? I remember a time when at least certain cartoons had the purpose of communicating an important moral or story at a level that could be understood by anyone (and then there were the other 99% that represented empty brain calories...what have we done to our kids?). I spend a lot of time and effort (with varying success) drawing cartoons on a chalkboard to illustrate basic geologic principles. Part of what is missing is the context. I often draw the above picture to illustrate a fault (and some important principles), but the lines are often meaningless, because students are not yet associating lines on a board with rocks in the real world. So I try to give the picture some "realism" (below). I suppose this is a little bit like the difference between stick figures, and the more complex drawings by comic artists (Superman and Batman!). Or not...
I ask the students to imagine they are walking through a canyon, and that they see rocks in the canyon walls that are aligned like those above. Since many of them have not done such a thing, or they were not looking at the rocks at the time, this can still be a meaningless exercise. As Mrs. Geotripper has led me down the road into art history, I have become aware that artists throughout history have had a similar problem.
Source: http://en.wikipedia.org/wiki/File:Masaccio7.jpg
Understandably, art throughout history has mostly been about gods, people, and to a lesser extent, animals (I'm thinking of cave paintings and petroglyphs, for instance). If rocks were ever included in a scene, they lacked structure, at least through the Renaissance. Note, for example the mountains in the scene above by Masaccio ("Tribute Money", c. 1426). Despite the vibrant colors and the life-like rendering of the humans, the mountains in the background are little more than gray blobs, lacking any kind of detail. The mountains in the image are mere cartoons.
Source
Leonardo da Vinci is often given credit for introducing real geological details in some of his works such as the meandering river in the "Mona Lisa", and the clearly layered aspect of the stones on the water in the "Virgin of the Rocks" seen above. This had a lot to do with the fact that he had observed and studied rocks in the course of his life. He saw, comprehended, and thus recorded the structure of the rocks in his works.

So...what do Leonardo da Vinci paintings and cartoons have to do with our journey to Death Valley last week? It has to do with the intrinsic and tangible value of the field trip in geoscience education. You can show draw cartoons on a chalkboard, you can show digital images on a screen, but nothing can ever substitute for the value of students standing on a mountainside, laying their hands on the rocks and making their own observations and judgements about the story told by the rocks.

For my students, and for the first pioneers of geology, telling the story of the rocks was a huge step. The mere recognition that rocks have a story was one of the great advances in the science, because in the European worldview of the middle ages, rocks were simply created as is, and changes since their origin have been minor. They barely deserved attention unless they contained valuable ores. Nicolas Steno (1638-1686), a Danish physician who spent much of his life in Florence, changed that.

St. Nick (yes, he was beatified in 1988!) first annunciated three of the four founding principles of stratigraphy, and each of them can be connected to the cartoons I used above. Take a look again, only now with labels:
If we recognize that each layer formed uniquely from the others, then we can start to talk about the order in which things happened. Which layer formed first? If you said "A", then you understand the principle of superposition: if sedimentary layers have not been overturned, the oldest layers will be found beneath the others.

Did these sedimentary layers form originally as sloping layers? If you think layers form horizontally, in the bottom of lakes, on the bottom of the sea, or on a floodplain, then you understand the Principle of Original Horizontality: most sediments originate in horizontal layers. If the layers are tilted, some outside force put them that way.

Did layer E or F originally end in a cliff? If you think not, you are on the verge of understanding the Principle of Lateral Continuity: sediments are continuous unless they abut against the edge of the original sedimentary basin, or they thin out. We understand that one can expect to find more of layer E or F in the general vicinity, because although erosion has removed the intervening rock, the original layers continued across a larger area than just this outcrop.

When did the faulting occur? If you think it came after the sediments were deposited, than you would be right, and you begin to understand the Principle of Crosscutting Relationships: faults and intrusive rocks are younger than the rocks they cut across. Steno may have written something about this, but the principle is associated more often with James Hutton in the latest 1700's and Charles Lyell in the early 1800's.

With this basic background (oh my, this post reads like a classroom lecture, doesn't it?), you can begin to understand the enthusiasm with which I presented these topics on our Death Valley trip. I was standing in front of the cliff in the picture below:
It's all there, including a sweet looking little fault cutting diagonally across the cliff face. We had reached Red Rock Canyon State Park on Highway 14 along the Garlock Fault and the El Paso Mountains in the Mojave Desert. The park is a showcase of geological principles, and it doesn't stop with the basic ones; those sedimentary layers are chock-full of fossils, and there are lava flows nearby too.

After presenting the basic principles we walked around the corner and encountered another outcrop, as seen below:
The students set out to identify the kinds of rocks, the order of the layers, and to define any structural complications. After only a few hours on the road, they were already deciphering the story of the Earth, as exposed in this corner of the Mojave Desert. What can you discern from this photograph? Can you do as well as they did?

Thursday, February 23, 2012

We're Going to be Shooting Blanks Soon...

There are times when I start feeling really discouraged. I'm trying to imagine a country that is trying to fight a war, but the soldiers are stymied by the fact that their country doesn't want to provide them the supplies and ammunition they need to fight the war. I imagine what it's like to be down in the trenches, firing at the enemy (while they fire back). We call for more bullets and reinforcements, but are told that our citizens (especially the richest ones) don't want to foot the bill for the battle. So we fight on, with dwindling supplies, fewer and fewer bullets, until all of the ammunition is exhausted. Disaster, of course, follows. I have a feeling that some regard this as not being a metaphor (like sending unarmored vehicles into Iraq), but it is one. The enemy in this war metaphor is ignorance.

Welcome to public education in the United States (and especially California) in the 21st century. At the very time that an educated, well-trained work force is critically needed to compete in the world, our society is turning its back on the teachers and institutions that can provide that education. Sure, we are in a recession (I know it is "officially" over, but not here in California and the Central Valley), but it is at times like these that we need to push all the harder for a better education system for all our citizens. An educated workforce is our ticket to beating the recession. But instead we are now rationing education, limiting it to those who can pay, and locking out those who cannot. It's just like rationing bullets in a war. If we want to compete in the world, we need to be sacrificing to give our children and our college students the best possible preparation for the workforce. And those who are best off in this economy should at the forefront of providing assistance.

Like I said, I'm discouraged. I read things like the GSA position paper below (cross-posted from Teaching the Earth Sciences), and at the same time I read an e-mail from my college president and division dean explaining that for the fourth year in a row we have to cut to the bone. We laid off tenured professors last year, and eliminated entire programs, including engineering. We aren't cutting to the bone anymore, we are cutting off arms and legs. And we are told once more to do more with less.

I suppose at this point I am supposed to say "I'm mad as hell and I'm not going to take it anymore" (If you missed the movie Network, check it out; the vision of the future was frighteningly spot on). But I'm not going to do that. I love teaching, and I love my students. I worry for them, and I want to give them the best shot I can. It would be nice just once in a great while to not hear politicians say how greedy we are to be asking for the resources to do our job in an adequate manner. We need ammunition to fight the war against ignorance.

This isn't the way things should be. Rant over...
----------------------------------------------

From the Geological Society of America

Acute Demand for U.S. Geoscientists Prompts Call for Higher Ed Action

Boulder, CO, USA – A recent American Geosciences Institute workforce evaluation estimates that by 2021, some 150,000 to 220,000 geoscience jobs will need to be filled. The AGI report notes that at current graduation rates, most of these jobs will not be able to be filled by U.S. citizens.

Citing great concern about the acute need for well-trained, well-educated geoscience graduates to fill the geoscience workforce, Geological Society of America President John Geissman is calling for colleges and universities to recognize the value of strong, adequately supported geoscience departments. High-quality geoscience education, Geissman notes, is essential to understanding and adequately addressing the “very pressing needs of our society,” including sustainability and human-caused climate change, as well as keeping the growing number of geoscience jobs filled by U.S. citizens.

Included in his call for action, Geissman refers to two very recently approved GSA Position Statements that focus on the importance of teaching earth science and expanding and improving geoscience education in institutions of higher learning.

Both position statements are online at www.geosociety.org/positions/. All GSA position statements include suggestions for how to implement and support the call to action.

The Importance of Teaching Earth Science recognizes that basic knowledge of earth science is essential to meeting the environmental challenges and natural resource limitations of the twenty-first century and notes that earth-science education should begin at the K–12 level and include advanced classes led by well-qualified science teachers.

Expanding and Improving Geoscience in Higher Education calls specifically for robust, well-supported geoscience departments not only to ensure an increase in the number of geoscience students available to the workforce but also to provide the training necessary “to address crucial societal issues that have the potential to impact global economic security and the well-being of human populations” across the globe.

John Geissman is a professor at The University of Texas at Dallas, emeritus professor at the University of New Mexico, and Geological Society of America president through 30 June 2012.

Strangers in a Strange Land: Just Getting There is Half the Battle...

And getting back home is the other half....

Death Valley is a heck of a long way from pretty much anywhere. The nearest big city is Las Vegas, 120 miles distant. The small town of Ridgecrest and village of Lone Pine are around 100 miles to the west. From our school, the distance is 400 miles. We only had a holiday weekend to explore the park, so on Thursday evening we packed the vans and drove the first 200 miles in the dark to set up camp near Bakersfield at the south end of the Great Valley. When the sun came up the next day, we would have only 200 miles (with a number of interesting distractions) to get to the park. We would have two full days to explore as much of the park as possible, and then a few stops in the morning on Monday before starting the long road home.

The travelers were community college students, which meant it was a very diverse group of 37 people thrown together into what I like to call a temporary dysfunctional family. There were 'old' people like me, and teenagers, a number of veterans and survivors from last year's trip, and a great many geology neophytes. They were going to learn the basic principles of geology in what I consider the finest way possible: total immersion.

I have to say the nicest thing I can about the quality of these students. If you are a teacher, you know the attitude that students often have, the "teach me, I dare you" look. Enthusiasm is, um, sometimes a rare commodity. It turned out I received a big stack of "Roadside Geology of Northern and Central California" to give away. We were almost packed and ready to go, and I casually mentioned that the books were in the lab, free for the taking. The picture below shows how special these students were...
Luckily, no one was trampled to death.
We arrived at our camp along the Kern River in the southernmost Sierra Nevada near Sharktooth Hill and set up camp in the rapidly dropping temperatures. I know my readers from the northern climes will chuckle, but we Californians really take a beating when we suddenly have to emerge from our homes and cars and start existing at temperatures below freezing. It was cold and damp, too.
But morning came, we packed our gear, and prepared for our geological adventure. This trip was an introduction to how geologists observe the world, so we started at the beginning: we looked at the landscape around us and started asking the basic questions that the first geologists did:

1) What rocks are found here?
2) What processes are acting on these rocks?
3) How did these rocks form, and how did they end up looking the way they do?

What we could see in the low foothills of the Sierra Nevada is that these rocks were not very resistant to erosion. There were no bold cliffs of hard igneous or metamorphic rocks, just gentle soil covered slopes. These rocks were loosely cemented sediments, mostly sand, silt and clay. They were in nearly horizontal layers that allowed us to define the basic unit of geologists: the formation, a distinctive layer of rock that is mappable, and which has definable contacts with the layers above and below. We talked about where these layers might have formed, and how we could tell. The issue of fossils came up, so we were able to talk about how geologists have found some very interesting remains in these hills: some clams and snail shells, and the bones of dolphins, whales, seals, manatee-like species, and many kinds of shark teeth. Clearly, a shallow sea once existed in this place.

The first, and sometimes hardest step in understanding the geological history of a place is to realize how completely a landscape will change over time. 20 million years ago, the Sierra Nevada did not exist as the high mountain range it is today. There were no Coast Ranges off to the west. There was only a shallow sea with a shoreline off to the east. The layers exposed here in the low foothills are called the Temblor Formation and the Round Mountain Silt, and these formations are one of the most famous fossil sources in California.

Not too surprisingly, listening to the talk of fossils caught the attention of the students. It was clear they couldn't wait to see for themselves if there were still fossils to find on the slopes above our campground. We drove a mile down the road, and the great search began.
After a few moments the first bone fragments were found, and then a few shark teeth. Over the next hour, almost everyone had found something of interest. It was a good start to the trip. We climbed back into the vans and headed over the Sierra at Tehachapi Pass, and into the Mojave Desert. Now that we knew what a formation was, we needed to start looking into how we tell the story of a sequence of layers and the various events that happened to them. We were headed to Red Rock State Park to learn the process.
Full disclosure: these are some of the extraordinary teeth that we found last year. I forgot to snap a picture of the fossils we found this year...

Tuesday, February 21, 2012

Strangers in a Strange Land: Stories From the Road in Death Valley

Strangers in a Strange Van....
Death Valley National Park is one of the country's greatest treasures from a geological point of view. Grand Canyon has the scenery and some great Proterozoic and Paleozoic sediments, but Death Valley has those things too, only multiplied: the Paleozoic layers at the Canyon are about 4,000 feet thick, with the Ordovician and Silurian missing. Death Valley's Paleozoic layers are more like 4 miles thick, and include some Ordovician and Silurian rocks. It is a geologic treasure. There are early and late Proterozoic rocks, granitic intrusions, volcanic rocks (both very old and very new), giant salt flats, dunes, and alluvial fans of all kinds. There are unsolved mysteries out here too.

I'm back from leading a five day trip through Death Valley with 36 students and volunteers, our second largest crew ever. It was exhausting, for the sole reason that a lot of experiences have to occur within a short time. I'll be posting about our adventures in coming days; I hope you will enjoy joining us on this journey!

Thursday, February 16, 2012

Strangers in a Strange Land: Hitting the Road in Death Valley

I was beginning a short web series about the volcanoes of San Francisco, but life briefly intrudes. I haven't been on the open highway for a while, but tomorrow we hit the road, me and a bunch of eager (I think) students. We are headed to the hottest driest place on the continent: Death Valley National Park. Hopefully the dieties will be merciful...

Of course, February is a delightful time to experience the Valley of Death, as temperatures are expected to be in the middle 70s, and night-time lows in the 40s. There were some windstorms earlier this week, but the weather is settling down. We will be camping and net access is...well, what do you expect in the most isolated corner of California? I will post a few updates if possible.

Death Valley National Park preserves one of the most complete geologic histories of any park on the North American continent. The oldest rocks developed possibly in late Archean time, and there is a three mile thick section of Proterozoic sediments, including some of the diamictites that provide possible evidence for the "Snowball Earth" hypothesis. The Paleozoic record includes thousands of feet of sediment representing nearly every period. There are Mesozoic granitic intrusions and sedimentary layers as well. There are Cenozoic sediments and extensive volcanic ash deposits. There are incredibly young volcanic features, including the Ubehebe Craters which made the news in the last few weeks. And the geologic structures! The park is a showplace of well exposed faults and folds, including numerous metamorphic core complexes and the famous turtlebacks. And there are even four species of fish, which evolved from one species in less than 20,000 years. The Devils Hole pupfish is the rarest and most threatened fish species in the country (they all live in a single submerged cavern opening).

And best of all, all of these fascinating features are collected into one of the most strangely scenic deserts to be found anywhere. It's so otherworldly that some areas of the park were used to represent other worlds in the Star Wars movies.

I'm looking forward to the next five days!

Monday, February 13, 2012

Magnitude 5.6 Earthquake in Northern California

There was a magnitude 5.6 earthquake in Northern California at 1:07 PM, at a depth of 20 miles. It took place in a lightly populated area, but I assume it was felt in Eureka and other north coast towns. It occurred on land between Eureka and Crescent City, roughly between Redwood Creek and the Klamath River, very close to the Hoopa Reservation.
As can be seen in the map above, earthquakes are not unusual in this area. It lies north of the triple junction where three tectonic plates come together (the Gorda, Pacific and North American). A subduction zone is forcing the Gorda Plate beneath the North American continent, and earthquakes are to be expected. There have been a series of magnitude 7 quakes in the region over the years, including the Petrolia earthquake of 1992. Ultimately the descending plate starts to melt, producing the magmas responsible for California volcanoes like Lassen Peak and Mt. Shasta.
As can be seen from the seismicity map of California above, there have been plenty of earthquakes within the last week, but there is nothing happening that is out of the ordinary. California averages several hundred earthquakes a week, although most are not felt.

Get the official details at this site: http://earthquake.usgs.gov/earthquakes/recenteqsus/Quakes/nc71734741.php#details
Keep track of all the quakes in California here:
http://earthquake.usgs.gov/earthquakes/recenteqscanv/

Sunday, February 12, 2012

The Other California: The Volcanoes of San Francisco...

After spending several posts talking about the "volcanoes" of Los Angeles, let's turn our attention to the other famous metropolis of our fair state: San Francisco and the Bay Area. Most people know of the famous association of earthquakes with the city by the bay, including the 1906 event, and the Loma Prieta quake of 1989. But what are the chances of a volcanic eruption in the Bay Area (note: I am using the term "bay area" loosely)? Are there any volcanoes looming about? And really, wouldn't lava in a Hollywood movie look a lot cooler if it were streaming down Lombard Street?
If you want to look ahead at some possible answers, might I suggest the work of Andrew Alden at Quest, Oakland Geology, and About Geology. The Bay Area is his geological beat, and I only pay the occasional visit. Also, don't forget the Interactive Geological Map of California!

Wednesday, February 8, 2012

The Other California: A "River" Runs Through It...And So Do Movie Crews

The term "river" and Southern California are rarely used in the same sentence. There are some things in the south part of the state called rivers, but anyone not from SoCal could ever mistake these miserable trickles of water for a real river. And yet...there are canyons in southern California that rival the Grand Canyon in depth. There are any number of impressive gorges that cause one to wonder how they ever came to be in this dry climate.

We discovered one of these canyons during our brief exploration of the Santa Monica Mountains last summer. We first crossed the mountains the previous day over a steep, narrow winding road over a high pass.  But the next morning we crossed the mountains by simply following a canyon all the way across. How did the little stream in Malibu Canyon manage to carve its way across the mountains?

The Santa Monicas are geologically a very young mountain range, having been pushed up only in the last few million years. One would not expect that rivers would be able to effectively carve deep canyons in such a short period of time, but that doesn't take into account several other factors: the increased precipitation during the ice ages, almost yearly flash floods, and the effect of rare but astonishing "atmospheric river" storms.
Malibu Creek, which has carved the deep canyon in the photos above, was in its present path before the Santa Monica Mountains began rising. As the mountains were pushed up, erosion by the river was able to keep pace, and Malibu Canyon was the result. Such rivers are called superposed or antecedent streams. It is an impressive (if not overly busy) way to cross the mountain range. Malibu Canyon is particularly deep because it has a much larger watershed than other creeks that don't cross the range.

In the heart of the mountains we encountered Malibu Creek State Park, a strikingly beautiful area of high sandstone cliffs. As we drove through, I had a sense of déjà vu, even though I was sure I had never been here before...
We took a side road above the park to check out some exposures of the Monterey shale. The Monterey is composed of diatomite, shale and chert that was deposited in deep marine basins along the California Borderland during the Miocene epoch. It is a source of much of California's oil reserves.
Along this stretch of the Mulholland Highway, the Monterey Shale is severely folded.
Looking down into the heart of Malibu Creek, I again had that sense of déjà vu. Korea looks like this doesn't it? Or is it the foothills of the Rocky Mountains? Or was it the high prairies? Well, actually those places don't look like this at all, but we think they do because Hollywood has made use of this landscape as a geographical substitute in numerous movies and television shows. The MASH set was in the canyon below the exposures of the Monterey (below). I could almost hear the helicopters...
A short distance down the road we found the Paramount Ranch, a former studio property that is now a part of the federally administered Santa Monica Mountains National Recreation Area. Dr. Quinn, Medicine Women was filmed here, as were a great many movies including Paleface" (1948) and "Son of Paleface" (1952), "Gunfight at the OK Corral" (1957), "Fancy Pants" (1950), "The Virginian" (1946), "Whispering Smith" (1948), "The Forest Rangers" (1942), "Miracle of Morgan's Creek" (1944), "The Perils of Pauline" (1947), "Geronimo" (1939), "The Streets of Laredo" (1949), "Buck Benny Rides Again" (1040), "Ruggles of Red Gap" (1935)," "Gunsmoke" (1931), "The Plainsman" (1936), "Hopalong Cassidy Returns" (1936), "Wells Fargo" (1937), "Union Pacific" (1938), "The Adventures of Marco Polo" (1938), "The Adventures of Tom Sawyer" (1938) and "Reds" (1981).
A western-style movie set is still maintained, and the park is still used for film productions. The day we came through, someone was preparing to shoot what the ranger described as a hip-hop video as imagined in the wild west.
We were star-struck! Well, ok, maybe not, but it was fun to imagine the history that infused this place, even if the 'history' was all imagined in the first place. I always wondered why Little House on the Prairie was surrounded by hills and mountains covered in brown grass and oak trees instead of prairie flatlands (Little House was filmed outside the Simi Valley a few miles to the north).


The Other California is my continuing series of the lesser-known geological sites in our beautiful state. Thanks to Mrs. Geotripper for the use of some of the pictures above!

Sunday, February 5, 2012

10 Reasons I Love Teaching Geology at a Community College

Oh, I cannot resist a meme involving top ten lists! Eric Klemetti at Eruptions started it on the topic of liking volcanoes. He was followed by Callan at Mountain Beltway on geologic structures, Siim Sepp at Sandatlas on sand,  Silver Fox at Looking for Detachment (on detachment faults, of course), and Hollis at In The Company of Plants and Rocks (on Wyoming). I teach geology at a community college, and I can't imagine a greater career. My list isn't on a specific geologic topic, it's about the joy of teaching about the Earth...

What happens when you teach geology at a community college?

We get to study anything we want
When I was in the master's program at Reno back in a different century, I had trouble settling on a geological discipline. I finally pursued a project in neotectonics, but I was constantly distracted by other stuff that was going on. Being at a community college means I have few opportunities for directed research, seeing as how I teach a large number of classes and labs. If a student asks a question on some area of the earth sciences, I get to track it down. Some years it's dinosaurs and paleontology. Other years it's seismology, or metamorphic rocks of the Sierra Mother Lode. I love learning about all of it.
We get to travel a lot to interesting places
I take my students a great many places around California, the American West, and the world. If you are are regular reader of my blog you already suspected this...
We get to meet interesting people
There seems to me to be no truer melting pot in our society than the campus of a community college. In a classroom you have people from all kinds of backgrounds thrown together: conservative and liberal (and "don't care"), rich and poor, young and old, people of faith and atheists, and people of many different cultures. The college lecture hall and especially the college laboratory is a place where people meet as true equals, and some actual communication can take place between people who would otherwise never interact. And I get to meet and learn from them all! I figure that in my 23 years of teaching, I have met something like 10,000 people. I obviously can't remember every single one of them, but it is kind of neat to be in some public place and have a stranger walk up and say "Hi, Mr. Hayes! You were my teacher years ago!"
We get to achieve goals:
Sometimes I sit in a restaurant or wander slowly through a store and I think about how the business has been there for whatever total of years, and the employees put in their shifts and look forward to their breaks. There is always a lot of hustle and bustle, there is always routine. The faces change, and sometimes the owners change, and at the end of the day, what has changed? A few more people have been fed, some more items have been sold, and for what purpose? Making money, and staying in business for another day. That is all well and good for a capitalist system, but what a mind-killing bore. There is nothing to work towards. There are no goals, at least not for the drones who do all the work (I imagine the owners have a goal of dominating their particular business; I learned that from the game of Monopoly). As a teacher, I and my students have a challenge, one that has a beginning and an ending. It may be that a student's goal is to pass the course somehow and move on, so they can start a career and...make money like a good capitalist. But I have the challenge of guiding students to know something more than they did when they started (what we call student learning outcomes). And the information is something that enriches their lives (and in the odd case, maybe even saving their lives; think earthquake preparedness).
We get to be creative
The art of teaching constantly requires thinking up new ways to enable learning on the part of the student. I have to challenge myself to break out of a mold when something isn't working. And I love drawing; by the end of the day I am usually covered with colored chalk. I've also grown to love photography, too.


Geology is fascinating
I can't speak for others, but I taught business math for a few semesters early in my career. If I had been teaching business math or accounting or economics for the last two decades, I think I would be nuts by now. I just can't imagine making certain subjects interesting. But there isn't a day that goes by when something fascinating isn't going on somewhere in the world. The stories are sometimes tragic, and sometimes awe-inspiring, but never boring. Even the most pedestrian subjects can be made interesting in some way (if you work at it)...even soils. We always have something strange and bizarre to talk about in class.
We help people discover a world outside their own
This isn't the same as the note above about traveling. Not all my students can go on field trips, but we get to open their eyes to the existence of strange and wonderful places beyond the confines of their normal everyday lives and hometowns. Every geological process involves examples from all over the planet; we use multimedia examples from our own lives or those of others to illustrate these incredible earth systems.
We get to contribute to the health of planet Earth
The decisions about how best to keep the planet liveable for 7 billion people are being made for the most part by those with a financial stake in outcomes and the politicians they lobby. Their priorities are not always correlated with everyone else's best interests. Without money, our best hope for just outcomes in environmental issues are the votes of an educated population. The community college system is on the front lines of providing that education.

We get to make a real and lasting difference
I am proud of what many of my former students have accomplished. A decent number of them went into geology, but more satisfying to me is how many of them are teachers now. There is a cascading effect of positive outcomes when students become teachers

Let's see, that's nine. What was the tenth? Oh yeah...

We're gonna get rich
Because teachers are held in the highest regard by society and especially by politicians. The politicians think that the people who are responsible for educating our children and teenagers deserve the highest possible compensation for their many years of academic preparation and daily challenges in the classroom. Now, if you actually believe in the accuracy of this last item, I recommend maybe not going into the field of education for a career. But if you want to look back on your life and say I changed things for the better, give a thought to teaching. And it's not too late to start no matter how old you are, or what career you are in now.

Saturday, February 4, 2012

The Other California: The Volcanic Mountains of the City of Angels

Volcanic mountains in Los Angeles???

Well, sure there are. Of course we need to define what is meant by "volcanic mountains". If you are imagining a chain of active volcanoes spewing out lava flows down Wilshire Boulevard, well, no there aren't any of those, despite what you might have seen in a Tommy Lee Jones movie a few years back.

Extinct volcanoes, maybe? No, I'm not really aware of any of those in the L.A. region either. I've never noticed any suspiciously conical hills in the metropolitan area in my travels that way. If you want to see a city that will probably be the setting for a great disaster movie (but not a very pleasant event if it were to happen for real), you might try a place like Auckland on the North Island of New Zealand. That particular city is built on four dozen volcanoes, including some that erupted only 600 years ago (below).
Yup, if you are a Kiwi, you can latch onto a 'hot' property here.
But there are volcanic mountains adjacent to Los Angeles. They just aren't actual volcanoes, as the original vents have long since been eroded away. The city is practically surrounded by exposures of volcanic rocks. There are some on the Palos Verdes Peninsula, in the mountains above Orange County, and in the hills near Glendora and Pomona. Perhaps the best place to see volcanic rocks near LA though, is the Santa Monica Mountains and their offshore extension, the Channel Islands.

I am guilty of ignoring the Santa Monica Mountains. I grew up in Southern California and never knew of them being much more than those hills up behind Malibu, and a place where I once attended the Renaissance Faire. I spent my available weekends up in the high country of the San Gabriels, the San Bernardinos, or the Sierra Nevada. This last summer I found that I was missing out on an extremely interesting and diverse mountain range. It has a geology professor's dream of intriguing rock exposures: metamorphic, plutonic, sedimentary, and as the post title suggests, volcanic rocks.
The volcanic sequence is not of a familiar origin. The so-called Conejo Volcanics were mostly extruded on the seafloor, only occasionally rising above the waves as islands. Volcanic activity is usually associated with divergent or convergent plate boundaries. The Conejo lavas were not exactly associated with either situation.

At divergent boundaries, the oceanic crust is pulled apart, releasing pressure on the underlying asthenosphere, a hot layer that is close to the melting point of the olivine-rich rocks of the mantle. The decompression allows a small portion of the asthenosphere to melt, producing basaltic lavas. At convergent boundaries oceanic crust is driven into the mantle underneath the adjacent oceanic or continental crust. As the rocks sink into the hotter asthenosphere, the added oceanic water acts as a catalyst or flux, lowering the melting point of the surrounding rocks. Bodies of magma called plutons rise through the crust forming volcanic arcs like the Andes, the Cascades or the Aleutian Islands.
Hey, the Santa Monica Mountains don't look like this at all...
A few other volcanic systems aren't related to plate boundaries. Thermal plumes, or hot spots, are responsible for sequential series of volcanoes on the sea floor (Hawaiian Islands) or on continents (Yellowstone caldera).

For most of the last 30 million years Southern California has been dominated by the lateral motions of the San Andreas fault system, a transform plate boundary. The fault system has not been a simple line, and the position of what we call the San Andreas fault has shifted about a number of times. One of the biggest changes was a shift eastward as the Gulf of California opened up around 4 or 5 million years ago. Transform boundaries are not normally associated with volcanic activity, but there are definite exceptions, and that seems to be the case in the area that is now exposed as the Santa Monica Mountains and Channel Islands.

The Santa Monica Mountains are part of the California province called the Transverse Ranges. They are one of only two mountain ranges in North America that are oriented east-west instead of the usual northerly trend (the High Uintas of Utah are the other). The discovery and acceptance of plate tectonics provided an elegant explanation for the origin of most of the world's mountain ranges like the Alps, the Himalaya and the Andes. The acceptance of the theory seemed to deepen the mystery of the origin of the Transverse Ranges. How could a northwest trending transform boundary produce an east-west trending set of mountains? Or did these mountains have anything to do with the transform faulting at all? Some researchers suggested the structure of the Transverse Ranges predated the onset of transform faulting. The Transverse Ranges are a treasure trove of ongoing and potential future research in structural geology and landscape evolution.

Tanya Atwater and the Educational Multimedia Visualization Center at U.C. Santa Barbara have provided us a marvelous animation that offers an excellent explanation for the onset of volcanism in the ranges around 13-16 million years ago (there are many excellent animations available for free download on the site).

As you watch the video unfold, you will see that the crustal blocks that constitute the Transverse Ranges have been literally rotated 90 degrees or more, having been caught between strands of the fault system. As the blocks rotated, extensional forces caused openings in the crust, forming deep sedimentary basins that collected thousands of feet of sediment, and also allowing magma to rise from the mantle forming volcanoes on the seafloor,  These are the rocks that make up much of the Santa Monica Mountains.
video
This animation is courtesy of the Education Multimedia Visualization Center.
Download this and many others at this site.

These volcanic rocks formed more than ten million years ago. Tectonic conditions have shifted and much of the region is now under the influence of compressional forces that are much less likely to result in volcanic activity. But it makes for a chaotic mess of earthquake activity as events like the 1994 Northridge earthquake can attest.

The Santa Monica Mountains are a confusing patchwork of federal, state, county, and city parklands and include large areas of private property. Land use ranges from densely urbanized areas (the mountains include parts of Hollywood and Beverly Hills ) to untrammeled wilderness. A good place to start planning your exploration is the website for the Santa Monica Mountains National Recreation Area. A look at the park map reveals the logistical headache of trying to administer the parklands.

The Other California is my ongoing exploration of the less-known geological corners of our beautiful state. Tens of millions of people visit the California Coast every year, and on one Labor Day weekend something like 800,000 people may hit the beaches at Malibu. In a year less than 500,000 will visit parks like Malibu Canyon or all of the federal units combined. The interior parks are great places to escape the crowds.

In the next post, we'll take a look at an unexpected canyon in the Santa Monica Mountains, and what does Korea have to do with anything?

Thursday, February 2, 2012

So Much for the Green Flash...But is the Coast Toast?

So much for the green flash...the consensus seems to be that I didn't see one, although I stubbornly hope that I saw it but just didn't happen to photograph it...anyway, courtesy of wikipedia, here is what one type of a real green flash, a mock-mirage flash, looks like.
I'm thinking that seeking a green flash and failing like I did is a bit like those first few times panning for gold. You'll see pyrite (fool's gold) a dozen times and think it might be gold, but when you see a gold flake for the first time you'll never misdiagnose pyrite again. I shall keep searching for the green...

I enjoyed the sunset that night immensely. There were all kinds of things going on, in the sky and over the water. The optical effects of a setting sun are always interesting of course. The distortion almost looked like a bomb blast. Or a light bulb...
It was interesting to see the amount of damage that has been done by wave action. This used to be part of the parking lot at Leo Carrillo beach. This is a look at the future; rising sea level and declining supplies of sand can only mean that coastal erosion will be increasing in extent and intensity.
 The seas were calm on this late summer afternoon. The effect was hypnotic and peaceful.
There were dozens of pelicans flying west along the coast line.  I love how they glide just inches above the waves; they are such graceful fliers. The Brown Pelicans almost disappeared in the 1960s as they absorbed so much DDT in their diet that their eggshells weakened and broke. With the ending of the use of DDT as an insecticide in the 1970s their population rebounded strongly.
What a shame it would have been if they had disappeared entirely. Does anyone besides me and Steven Spielberg think that they look like resurrected pterodactyls?

The sun sank below the horizon and the clouds briefly turned orange and pink. We headed back to camp up in the canyon.
I glanced at one of the rocks on the beach that was being used as rip-rap (wave barriers). The holes made me wonder about something. Fifteen years ago a movie was released to a certain amount of derision among geologists: Volcano. Tommie Lee Jones played a gruff but lovable emergency services director, and Anne Hecht played the geologist with the heart of gold. The volcano sucked (literally it sucked: Anne's friend in the movie got sucked down a hole into the lava). There were earthquakes, there were exploding buildings, there were lost children, and melting people.
Obviously, the idea of a volcano erupting in downtown Los Angeles is preposterous. There must not be a volcano within hundreds of miles of the city. I mean, there aren't any volcanic mountain ranges in southern California...right? The faults are all strike-slip and thrusts. It just doesn't seem likely. So how to find out? Maybe, a look at the interactive geologic map of California from the California Geological Survey (clue: most of the volcanic rocks on the map are pink or orange...).
Is the coast really toast, or is it already toasted?