Monday, May 30, 2016
Just for Fun, a Minor Monday Mystery
Where am I and how do you know? There is the obvious clue provided by the street signs, but if they weren't there, would you have any way of knowing something of where I spent the day? A clue: the picture was taken at lunch time!
Tuesday, May 24, 2016
Airliner Chronicles: Stuck on a Plane with a Proselytizer...
And really, I felt sorry for the poor guy who was stuck sitting with me on the plane flight from St. Louis to LAX. Oh, I wasn't trying to convert the poor guy into some religion. No, he got the full-court press from me about the importance of understanding what was going on 35,000 feet below us on the ground. He was being proselytized into the world of geology.
People who fly a lot for whatever region may be forgiven for not paying attention to the grand panorama unfolding below them, but to a geologist, the extra dimension is pure gold. Seeing a large swath of the Earth's surface grants a whole new perspective to understanding geological processes.
I didn't have a working GPS on the flight, so I had to guess our location for the first two hours of the flight, somewhere over Missouri, Oklahoma, or Texas. But it was unmistakable that we were over oil and gas country. The drilling rigs and their connecting roads could not be missed. Some politicians once described the "footprint" of oil and gas drilling on a landscape as just a few acres being torn up. Seeing the scene from above suggests that the footprint is "small" in the sense that a spider web is a few strings of dragline silk.
I was lost until the mesas and plateaus appeared. I knew at that point that we were in New Mexico, and I correctly figured out that we passed Sante Fe and Las Vegas, New Mexico. My seatmate, a Pittsburgh resident, got a bit confused about the Las Vegas part; "We're in Nevada already?". I crushed his hopes (that is NOT the way to proselytize, by the way).
The landscape turned into a rainbow of color, and I suddenly knew our precise location better than a GPS unit. We had reached the Painted Desert area of Petrified Forest National Park in Arizona. A plateau covered by basalt flows was breached by erosion, exposing the brightly colored layers of the Triassic Chinle Formation. The Triassic rocks reveal the beginnings of the dinosaur domination of our planet, and the floodplain and river deposits contain some of the earliest dinosaur species known. There is the wood, of course, and a stunning variety of amphibians and reptiles, including Phytosaurs, huge crocodile-shaped creatures that exceeded 30 feet in length.
Just west of Petrified Forest, I got the finest treat of the day, a perfect view of Meteor Crater. I put the best of the pictures up in yesterday's post.
A short time later, more colorful rocks came into view, but they were older than the Chinle of Petrified Forest. We had reached the Pennsylvanian and Permian rocks of the Supai Group. These rocks are the same ones exposed in the walls of the Grand Canyon, about eighty miles to the north. This is the edge of the Colorado Plateau, where the high flat landscape gives way to the deep fault valleys of the Basin and Range Province. Because the valleys are so deep, erosion eats away at the edge of the plateau, forming scenic deep gorges like Oak Creek Canyon, north of Sedona.
I was distracted by some wildfires burning in the thick forests of the plateau. I finally realized I was missing one of the more extraordinary features of the Colorado Plateau, the San Francisco Peaks Volcanic Field. The field is a vast basalt lava plain populated by hundreds of cinder cones, and an immense stratovolcano that reaches more than 12,000 feet in elevation, the highest point in all of Arizona. The edifice of the San Francisco Peaks has been altered somewhat by erosion; it was once 4,000 feet higher. It would have been the highest point in the lower 48 states.
The existence of the volcanic field is somewhat of an enigma. There's no obvious reason for it being here. There are suggestions that it is the result of an incipient hot spot, but the idea is not wholly accepted. The field is active; an eruption took place less than a thousand years ago.
Somewhere near the end of the flight, my poor beleaguered seatmate asked a geological question. He was wondering why there was a gigantic hole in the ground that wasn't a meteor impact crater. It was an open pit mine, probably for copper. I almost had a convert to the ages of rock!
People who fly a lot for whatever region may be forgiven for not paying attention to the grand panorama unfolding below them, but to a geologist, the extra dimension is pure gold. Seeing a large swath of the Earth's surface grants a whole new perspective to understanding geological processes.
I didn't have a working GPS on the flight, so I had to guess our location for the first two hours of the flight, somewhere over Missouri, Oklahoma, or Texas. But it was unmistakable that we were over oil and gas country. The drilling rigs and their connecting roads could not be missed. Some politicians once described the "footprint" of oil and gas drilling on a landscape as just a few acres being torn up. Seeing the scene from above suggests that the footprint is "small" in the sense that a spider web is a few strings of dragline silk.
I was lost until the mesas and plateaus appeared. I knew at that point that we were in New Mexico, and I correctly figured out that we passed Sante Fe and Las Vegas, New Mexico. My seatmate, a Pittsburgh resident, got a bit confused about the Las Vegas part; "We're in Nevada already?". I crushed his hopes (that is NOT the way to proselytize, by the way).
The landscape turned into a rainbow of color, and I suddenly knew our precise location better than a GPS unit. We had reached the Painted Desert area of Petrified Forest National Park in Arizona. A plateau covered by basalt flows was breached by erosion, exposing the brightly colored layers of the Triassic Chinle Formation. The Triassic rocks reveal the beginnings of the dinosaur domination of our planet, and the floodplain and river deposits contain some of the earliest dinosaur species known. There is the wood, of course, and a stunning variety of amphibians and reptiles, including Phytosaurs, huge crocodile-shaped creatures that exceeded 30 feet in length.
Just west of Petrified Forest, I got the finest treat of the day, a perfect view of Meteor Crater. I put the best of the pictures up in yesterday's post.
A short time later, more colorful rocks came into view, but they were older than the Chinle of Petrified Forest. We had reached the Pennsylvanian and Permian rocks of the Supai Group. These rocks are the same ones exposed in the walls of the Grand Canyon, about eighty miles to the north. This is the edge of the Colorado Plateau, where the high flat landscape gives way to the deep fault valleys of the Basin and Range Province. Because the valleys are so deep, erosion eats away at the edge of the plateau, forming scenic deep gorges like Oak Creek Canyon, north of Sedona.
I was distracted by some wildfires burning in the thick forests of the plateau. I finally realized I was missing one of the more extraordinary features of the Colorado Plateau, the San Francisco Peaks Volcanic Field. The field is a vast basalt lava plain populated by hundreds of cinder cones, and an immense stratovolcano that reaches more than 12,000 feet in elevation, the highest point in all of Arizona. The edifice of the San Francisco Peaks has been altered somewhat by erosion; it was once 4,000 feet higher. It would have been the highest point in the lower 48 states.
Somewhere near the end of the flight, my poor beleaguered seatmate asked a geological question. He was wondering why there was a gigantic hole in the ground that wasn't a meteor impact crater. It was an open pit mine, probably for copper. I almost had a convert to the ages of rock!
Monday, May 23, 2016
Airliner Chronicles: When Disaster Arrived from the Heavens
I thought briefly of making this one of those "What is it?" kind of posts, but it seemed kind of obvious. We were flying home from our weekend in St. Louis, and without a GPS, I was trying to get myself situated correctly into the geography that was drifting by slowly far beneath us. I was not too particularly successful at orienting myself while over the "flyover" states of Oklahoma, Kansas or Texas, but the fracking rigs were obvious, as were the irrigation rings, where farmers are pumping up fossil water from the Great Plains Aquifer and letting it evaporate in the intense sunshine.
Once we reached lands with actual topography, I began to suspect where we were...was that Las Vegas, New Mexico? What about that town? Santa Fe? It turned out I guessed pretty well, and also recognized the holy peak of Mount Taylor in New Mexico, and the Ambrosia Lake Mining District. But it wasn't until I saw the intense magenta of the Painted Desert and the unique road loop near the northern visitor center at Petrified Forest National Park that I knew precisely where I was. And then I realized that Meteor Crater was just ahead. I was sure that the plane would go right over it and it wouldn't be visible, but luckily I was wrong. I had a box seat view (although metal cylinder seat view would be a better description). I was, in a word, thrilled. I'd never seen it before from above.
Meteor Crater is justly famous as one of the best preserved meteorite impact sites in the world. Roughly 50,000 years ago, when camels, horses and mammoths were grazing the grasslands, the sky lit up with fire and a chunk of space rock about fifty feet long impacted the surface at a speed of 30,000 mph. The ensuing cataclysm produced a crater about 1,200 m (3,900 ft) in diameter, and 170 m deep (570 ft).
Meteor Crater is privately owned, but the company has done a good job of protecting this unique site. They are especially good at accommodating school groups on tours. You can check out their website at http://meteorcrater.com/.
The "Airliner Chronicles" was one of my first web series, and whenever I fly somewhere, I add to it. I got a few other shots, so if I am not too distracted with Hawaii preparations, I will post some.
Once we reached lands with actual topography, I began to suspect where we were...was that Las Vegas, New Mexico? What about that town? Santa Fe? It turned out I guessed pretty well, and also recognized the holy peak of Mount Taylor in New Mexico, and the Ambrosia Lake Mining District. But it wasn't until I saw the intense magenta of the Painted Desert and the unique road loop near the northern visitor center at Petrified Forest National Park that I knew precisely where I was. And then I realized that Meteor Crater was just ahead. I was sure that the plane would go right over it and it wouldn't be visible, but luckily I was wrong. I had a box seat view (although metal cylinder seat view would be a better description). I was, in a word, thrilled. I'd never seen it before from above.
Meteor Crater is privately owned, but the company has done a good job of protecting this unique site. They are especially good at accommodating school groups on tours. You can check out their website at http://meteorcrater.com/.
The "Airliner Chronicles" was one of my first web series, and whenever I fly somewhere, I add to it. I got a few other shots, so if I am not too distracted with Hawaii preparations, I will post some.
Sunday, May 22, 2016
Pele is a Capricious Goddess...Part Three, a Precious Gift from a Mysterious Woman
One of the most awe-inspiring moments of my life |
The 2006 lava flow ocean entry from 3,000 feet above and 20 miles away on Chain of Craters Road |
I was not really expecting to see much. The problem is that the coastal cliffs around a lava entry are dangerously unstable. As the lava hits the water, it shatters and forms thick layers of unstable cinders while being covered by lava flows. Every so often, the cinders slide downward, and the lava bench suddenly collapses into the sea. A number of people have been killed because they were standing on the benches when they collapsed. So, the national park service had erected a rope barrier to keep people from the most dangerous areas. Unfortunately, there was no view possible of the lava itself, according to reports. Just the bright orange glow of the steam rising from the turmoil below the coastal cliff.
The glow of moonlight on the ocean, and the glow of lava on the steam. |
Still, it was worth a try. I told my wife and son and nephews that I would hike out, be safe, look at the glow of the invisible lava, and be back to the hotel by 9 PM or so. I took water, a flashlight, extra batteries, and my brand-new camera that I had bought that morning, and was just beginning to learn to use.
The hike was longer than I expected. There were so many people parked at the end of Chain of Craters Road that I literally had to walk an extra mile just to reach the trailhead. The flows were entering the sea two miles away, over trail-less pahoehoe flows. The sun set way too quickly and for route-finding I was down to my flashlight, and flashing beacons set up every quarter mile or so. Plenty of people were walking back with their flashlights, so the route was clearly evident. Most of the people I talked to expressed disappointment. Nothing to see but glowing steam. There were a few idiots who crossed the barriers, but even they couldn't get close enough to see anything. I was getting very tired. Pahoehoe may be smooth, but is still very uneven, and it only takes a single misstep to twist or break an ankle. I made it to the rope barrier, and could now see the glow and the steam. It was actually an awe-inspiring moment, as the moon had risen and was reflecting off the ocean behind the steam plumes. But no lava.
And then things got different in a hurry |
I realized that it had become very lonely. The only others about were four people in a party, and a single flashlight off in the distance headed back to the road. I hung with the four people and a lady appeared out of the darkness (it only occurred to me later that she didn't have a flashlight). She hinted that we might want to walk to the far eastern end of the rope barrier, another quarter mile away. And then she disappeared into the darkness again. I looked at my watch. Already 9:00 PM. I was going to be way overdue. But, what was out there? What was the lady talking about?
Curiosity got the best of me, and I set off for the far end of the barrier. After 20 minutes or so, I surmounted a small cliff and looked down, and saw one of the most beautiful sights I have ever seen.
I was standing at the top of a thirty-foot cliff that marked the edge of the latest bench collapse (The safe edge, if you are wondering). No more than 30 minutes earlier, a lava tube had broken through, and lava was starting to pour across the bench to the 15-foot high beach cliff a mere hundred yards away. I stood entranced as the lava flowed like syrup across the slope below me. The finger of lava flowed slowly to the edge of the cliff and spilled over into the surf.
The five of us were the only people out of hundreds of visitors that day who saw the glorious scene before us. Except that mysterious woman...Needless to say, I was in a heap o' trouble when I walked into the hotel lobby after midnight. But I can never forget the incredible gift of that magical sight of lava pouring into the sea. And that mysterious woman in the darkness.
PS: I found a USGS photograph of the coast taken on the same day I was there. The parking was in the distant brown area, the black is recent lava flows, and the gray foreground area is the active lava delta. The rope barrier is hard to see, but it was uphill from the lava delta. The new lava breakout that I saw happened at the bottom of the picture at the edge of the gray delta.
PSS: I did manage to figure out the video function on the new camera, but of course I should have taken more.
Labels:
Hawai'i Volcanoes National Park,
Hawaii,
lava bench,
pahoehoe lava,
Pele
Saturday, May 21, 2016
Pele is a Capricious Goddess (reprised)...Part Two
Continuing the story from the previous post,
I had a second chance to see a volcano in action in 2004. I was the
newly elected president of the Far West Section of the National
Association of Geoscience Teachers, and for my first conference, I had
persuaded someone to sponsor a meeting in Hilo, Hawaii. The volcano on the Big Island at Pu'u O'o had
continued to be active over the previous two years and was still going
strong as the date of the conference approached. Lava was still traveling from the cinder cone on the east rift zone of Kilauea and traveling through lava tubes to the ocean. I was thrilled that a
bunch of fellow teachers would be able to see an active lava flow!
Except (and there always seems to be some kind of terrible "except" to stories like this)...as the final days approached, the flow activity started to wane. The HVO reported that blockages had started to occur in the upper reaches of the lava tubes that were feeding the ocean entries, and the lava flows were slowing considerably, declining to almost nothing. Every morning I went online to check on the latest HVO reports, and got a sinking feeling.
My daughter arrived on the island a day before me, and hiked out to see the lava flows. It was down to a single dribble, no wider than a pencil, falling into the sea. No wider than a pencil. And then it stopped...
The next day, I hiked out to the flow as fast as I could, and saw...well, I saw what you can see in the picture above: steam from a recently ended flow. I searched desperately for any kind of small break out, any sign of active lava, but all there was was steam rising from cracks here and there. All I got for my trouble was a badly scraped arm and palm when I slipped and fell onto a day-old lava flow. I was not aware until that day that fresh basalt flows are usually covered with a thin veneer of obsidian (volcanic glass) that gives the lava flow a silvery metallic appearance. The glass starts to break up right away, forming jagged shards that are like small razors lying about the surface.
Still, there is great beauty in new rock. The patterns in the pahoehoe lava surfaces are endlessly fascinating, and there is a grandeur in the barren surfaces of a day old lava flow. It is an absolutely sterile surface that has never before existed. A new beginning...
Lava flowing into seawater has a tendency to explode on contact, forming fine sand-sized particles. Kilauea had already destroyed one of the most cherished black sand beaches in Hawaii, but a new beach, however impermanent, had appeared to replace it.
Pele had given the gift of new land on the island, but I was not privileged in this instance to see it happen. But patience is a virtue. It would be another two years before I made it to the islands, but it was worth the wait. That story will have to wait for the next post!
This is an expanded version of a 2009 blog post that preceded the first field studies course that I ever taught on the Hawaiian Islands. We're leaving in a week for the islands for our second-ever course, so I'm thinking volcanic subjects these days.
Except (and there always seems to be some kind of terrible "except" to stories like this)...as the final days approached, the flow activity started to wane. The HVO reported that blockages had started to occur in the upper reaches of the lava tubes that were feeding the ocean entries, and the lava flows were slowing considerably, declining to almost nothing. Every morning I went online to check on the latest HVO reports, and got a sinking feeling.
My daughter arrived on the island a day before me, and hiked out to see the lava flows. It was down to a single dribble, no wider than a pencil, falling into the sea. No wider than a pencil. And then it stopped...
The next day, I hiked out to the flow as fast as I could, and saw...well, I saw what you can see in the picture above: steam from a recently ended flow. I searched desperately for any kind of small break out, any sign of active lava, but all there was was steam rising from cracks here and there. All I got for my trouble was a badly scraped arm and palm when I slipped and fell onto a day-old lava flow. I was not aware until that day that fresh basalt flows are usually covered with a thin veneer of obsidian (volcanic glass) that gives the lava flow a silvery metallic appearance. The glass starts to break up right away, forming jagged shards that are like small razors lying about the surface.
Still, there is great beauty in new rock. The patterns in the pahoehoe lava surfaces are endlessly fascinating, and there is a grandeur in the barren surfaces of a day old lava flow. It is an absolutely sterile surface that has never before existed. A new beginning...
Lava flowing into seawater has a tendency to explode on contact, forming fine sand-sized particles. Kilauea had already destroyed one of the most cherished black sand beaches in Hawaii, but a new beach, however impermanent, had appeared to replace it.
This is an expanded version of a 2009 blog post that preceded the first field studies course that I ever taught on the Hawaiian Islands. We're leaving in a week for the islands for our second-ever course, so I'm thinking volcanic subjects these days.
Labels:
Hawaii,
Hawaii Volcanoes National Park,
lava flow,
pahoehoe lava,
Pele
Friday, May 20, 2016
Pele is a Capricious Goddess...Part One (A Return to the Realm of Fire)
Note to my Geology 190 Students: this IS NOT a picture from my current visit. Lava is NOT flowing this way right now. I offer NO GUARANTEES that anything we see on our trip in two weeks will be anything like this. The reasons are described below....
For everyone else: I wish you could join us! We are headed to the Hawaiian Islands in a few weeks so I am revisiting some posts from 2009, when our students last joined me. I've made some changes to the original post and added lots of photos.
Pele is the volcano goddess on the Hawaiian Islands, and she is a powerful deity in the lives of the islanders. Think about it: the only substantial piece of land above sea level for thousands of miles in all directions is the result of volcanic eruptions that built the islands up from ocean crust lying beneath 3 miles of ocean water. All existence on the islands starts with volcanic creation, and all is lost when the volcanoes ultimately die out and fall prey to the waves and weathering. These beliefs demand a certain amount of respect when paying a visit to the islands.
The title of my post is meant in a slightly humorous vein, but my experiences in four trips make me start to wonder. Let me explain...
My first trip to the islands was in 2002, and I was full of hope that I would get a chance to see a lava flow, even though there seemed little chance of it from reading the 2002 status reports from the Hawaii Volcanoes Observatory. Lava had not reached the ocean for many months, with activity confined to the region around Pu'u O'o many miles from any roads or trails. Then, just prior to my plane flight, lava started flowing rapidly down the slopes of the shield, and began pouring in a spectacular manner over the Pulama Pali (a 500 foot fault scarp/cliff) and onto the coastal plain...only a mile from the end of Chain of Craters Road! At one point seven streams of lava were pouring over the cliff! And the lava was now crossing the coastal plain on the way to the sea. I was going to see an incredible show!
But....
The lava flow had started the largest forest fire to occur in the park in 15 years. And the fire fighters had to close Chain of Craters Road to provide access for their fire-fighting equipment. I was not going to see the lava flow! I was crushed, frustrated beyond reason!
But...
Being a Californian, I expect that firefighters work day and night to fight fires, but Hawaii was different. The crews shut down at 5:00 PM, and went home for a nap. The road opened. I, and hundreds of other people drove the road in one long stream of cars, and started hiking over the older flows towards the new flows, now only a quarter mile from the ocean. We could walk right up to the edge of the oncoming flow and feel the intense heat. It was not moving fast, only a few inches a minute, but it was hypnotic. There is nothing quite like standing at the edge of a new creation, knowing that this was how these islands came to exist, one flow after another, after another until they are tens of thousands of feet thick, finally emerging from the sea. The new land provided a platform for the survival of the living flotsam and jetsam that once every few thousand years washed up on the island. These pioneers eventually evolved into the complex ecosystem we see today in Hawai'i.
This was not the first time I would experience Pele's fire. I've made a number of journeys to the islands in the years since, and every visit to Pele's realm was unique, and in one particular instance, downright mysterious and a bit mystical.
In the next post: Pele gets moody...
That's a much younger version of myself, from 2002 |
My very first sight of flowing lava, 2002, Chain of Craters Road |
Pele is the volcano goddess on the Hawaiian Islands, and she is a powerful deity in the lives of the islanders. Think about it: the only substantial piece of land above sea level for thousands of miles in all directions is the result of volcanic eruptions that built the islands up from ocean crust lying beneath 3 miles of ocean water. All existence on the islands starts with volcanic creation, and all is lost when the volcanoes ultimately die out and fall prey to the waves and weathering. These beliefs demand a certain amount of respect when paying a visit to the islands.
An offering to Pele at Halemaumau, 2002 |
The title of my post is meant in a slightly humorous vein, but my experiences in four trips make me start to wonder. Let me explain...
My first trip to the islands was in 2002, and I was full of hope that I would get a chance to see a lava flow, even though there seemed little chance of it from reading the 2002 status reports from the Hawaii Volcanoes Observatory. Lava had not reached the ocean for many months, with activity confined to the region around Pu'u O'o many miles from any roads or trails. Then, just prior to my plane flight, lava started flowing rapidly down the slopes of the shield, and began pouring in a spectacular manner over the Pulama Pali (a 500 foot fault scarp/cliff) and onto the coastal plain...only a mile from the end of Chain of Craters Road! At one point seven streams of lava were pouring over the cliff! And the lava was now crossing the coastal plain on the way to the sea. I was going to see an incredible show!
The U.S. Geological Survey took this photo the day I arrived on Hawai'i, June 11, 2002. |
But....
The lava flow had started the largest forest fire to occur in the park in 15 years. And the fire fighters had to close Chain of Craters Road to provide access for their fire-fighting equipment. I was not going to see the lava flow! I was crushed, frustrated beyond reason!
One day later, it was still spectacular to see. |
But...
Being a Californian, I expect that firefighters work day and night to fight fires, but Hawaii was different. The crews shut down at 5:00 PM, and went home for a nap. The road opened. I, and hundreds of other people drove the road in one long stream of cars, and started hiking over the older flows towards the new flows, now only a quarter mile from the ocean. We could walk right up to the edge of the oncoming flow and feel the intense heat. It was not moving fast, only a few inches a minute, but it was hypnotic. There is nothing quite like standing at the edge of a new creation, knowing that this was how these islands came to exist, one flow after another, after another until they are tens of thousands of feet thick, finally emerging from the sea. The new land provided a platform for the survival of the living flotsam and jetsam that once every few thousand years washed up on the island. These pioneers eventually evolved into the complex ecosystem we see today in Hawai'i.
Lava at night is other-worldly |
This was not the first time I would experience Pele's fire. I've made a number of journeys to the islands in the years since, and every visit to Pele's realm was unique, and in one particular instance, downright mysterious and a bit mystical.
In the next post: Pele gets moody...
Thursday, May 19, 2016
Airliner Chronicles: Finding Fault by Flying
Flying can be no fun whatsoever, what with the lines, the waits, the security checks, surly attendants, and the tarmac delays. It would be intolerable were it not for window seats. So while I'm in connecting flight limbo, here is a sight from my flight between Oakland and LAX today. We generally flew right over the San Andreas fault for most of the flight, but in Southern California, the fault takes a more southeasterly trend and it suddenly appeared below me. This section of the San Andreas is just west of Gorman at the summit of the Grapevine, the point where Interstate 5 crosses the Transverse Ranges on the way into Los Angeles.
The "Airliner Chronicles" is a throwback to the very first blog series I did way back when. I don't fly all that often, but if there is good geology below, you can be sure that I'm trying to capture it in pictures.
The "Airliner Chronicles" is a throwback to the very first blog series I did way back when. I don't fly all that often, but if there is good geology below, you can be sure that I'm trying to capture it in pictures.
Labels:
Gorman,
Grapevine,
Interstate 5,
San Andreas fault,
Transverse Ranges
Monday, May 16, 2016
The Other California: A Chance to See a Unique Piece of our State, our local Galapagos Island
Santa Cruz Island in Southern California. Here is your chance to explore this dynamic and unique ecosystem! Source National Park Service |
It's also important to know that despite our limited resources, our administration recognizes the value of field experience not just in geology, but also biology, archaeology, and anthropology. Students who have pursued their education at our school have had opportunities to explore far-flung parts of our world, including Scotland, Australia, New Zealand, Italy, Switzerland, Canada, Baja California, and all eleven western states. It is a challenge to put such trips together, and they can be expensive, but the experience and knowledge gained is priceless.
Which brings us to today's topic. Early on in my blogging career (in the Pre-Pleistocene year of 2008), I had a regular feature called the "Other California" which describes those parts of our fair state that don't always show up on the postcards and travel brochures, but which display incredible geology and natural history. Our state is rich with landscapes and species that are found nowhere else. And so today I want to let you know about a marvelous opportunity to see one of our most unique landscapes, the Channel Islands.
The Channel Islands are the oceanic extension of the Transverse Ranges in Southern California. Structually, they've had a strange history that includes being a part of the Earth's crust that has rotated more than 90 degrees from their original orientation. They have been compressed and faulted, and isolated from the mainland for several million years. That means that fauna and flora have been isolated as well, and they have undergone selective pressure in order to survive. There are more endemic species here than anywhere else in the state. There is a species of bird, the Island Scrub Jay, that is found nowhere else, as well as a canine, the Santa Cruz Island Fox. As recently as 10,000 years ago there was a race of Pygmy Mammoths who survived on the islands for some time after their relatives had died out on the mainland. And...humans lived with and occasionally hunted them! The islands have a rich archaeological heritage of the Chumash people that goes back thousands of years.
You have a chance to explore Santa Cruz Island with an archaeologist, Professor Susan Kerr, and a biologist, Professor Teri Curtis through the auspices of Modesto Junior College. The class is Archaeological and Biological Field Studies of the Channel Islands (Anthropology 155 and Biology 155 for a total of 2 semester units) and it will take place on August 7-12 on Santa Cruz Island. Cost includes registration fees for the class and $480 for housing, transportation, meals and activities, including kayaking and hiking. There is an information meeting on May 19th for those of you who live in the Modesto region, at 6 PM in Science Community Center room 212 on the west campus of MJC. If you can't make it to the meeting, contact Susan Kerr (kerrs -at- yosemite.edu) or Teri Curtis (curtist -at- yosemite.edu). I hope you can join them!
Sunday, May 15, 2016
Cherishing Our Rivers: A Journey on the Water with the Tuolumne River Trust
Are you lucky enough to live near a river? For much of my life I didn't
have that privilege. Southern California has creeks at best, except when
they were flooding and otherwise causing havoc. The creeks often flowed
through incredibly beautiful mountains and valleys, but they can't be a
source of life for human civilization. We're too busy using what little
water there is that there is barely enough to maintain a healthy
ecosystem. Southern
California has to import around 85% of the water that it uses.
People who live in Northern California or the Pacific Northwest might smile when I describe my Tuolumne as a river. Compared to the mighty rivers like the Columbia it is a middling stream. The thing is, it lies about that point in the northward journey in California where the rivers provide sufficient water for local use that it doesn't have to be imported from elsewhere (indeed, much of the water from the Tuolumne is exported to the Bay Area). We depend mostly on groundwater for domestic use, and the groundwater is replenished in part by the river. Most of the river goes to irrigation, but some is allowed to flow into the San Joaquin River and on to the ocean (not willingly, it should be noted; there are some who would just as soon use all of it).
The Tuolumne River begins high in the Sierra Nevada, flowing through Tuolumne Meadows in Yosemite National Park. It plunges into the Grand Canyon of the Tuolumne, a spectacular gorge that is as deep as that other canyon in Arizona. It is briefly stopped and diverted at Hetch Hetchy Reservoir, and then flows through a lesser-known gorge (unless you are a rafting enthusiast) to Don Pedro Reservoir. More water is siphoned off, but part of the river continues through the Sierra Nevada foothills and Mother Lode, and finally flows into the Great Valley, where it joins with the San Joaquin.
That's where I found myself today, rafting a section of the Tuolumne where it flows through the foothills between La Grange and Turlock Lake State Recreational Area. I had joined the Tuolumne River Trust on their By Land and By Water Canoeing trip, where I was serving as the resident geologist (literally 'resident', as I live just ten miles downstream). It was a fine adventure for the twenty or so participants, who were helping raise funds for the Trust.
What do they do? The Trust organizes river clean-ups, restoration of regions burned by the Rim Fire, and educational opportunities for children and adults. They also do political advocacy, as a voice for the river itself in the cacophony of agricultural and urban water interests. It's a great organization that deserves your support!
The river was alive with birds, bugs and amphibians. I glanced at a bug hovering a foot or so over the river, and it suddenly disappeared in the mouth of a swallow. The swallows accompanied us along the entire length of our journey. Maybe all the oars hitting the water was stirring up the bugs! I saw an old telephone pole in the distance, and immediately recognized the huge pile of sticks and random debris as an Osprey nest. Both parents were there, along with at least one chick (barely visible to the right of the birds in the picture above).
The Ospreys were not happy with the rafters and canoers below, and let them know in no uncertain terms. They relaxed when we floated by and headed downstream.The river is a perfect habitat for these grand birds. 90% or more of their diet is fish, and they are experts at landing feet-first in river to grab unwary ones floating near the surface.
There is some interesting geology on the lower river. The cliffs we passed had outcrops of white or tan-colored volcanic ash called the Valley Springs Formation. The ash was the result of gigantic eruptions of rhyolitic magma at calderas located in central Nevada! Given the media fascination with Yellowstone "super-volcanoes", people might be surprised to find that similar calderas erupted all across the American West between 20 and 30 million years ago.
A bit further downstream there are exposures of the Mehrten Formation. It originated from volcanic mudflows related to the Cascades-style stratovolcanoes that once existed near the present day summit of the Sierra Nevada around 10 million years ago. Sediments within the unit have yielded an array of fossils including ancient camels and horses, giant tortoises, and strange 8 foot long saber-toothed salmon! Younger rocks above the Mehrten have given up Mammoths, Mastodons, Saber-tooth Cats, American Lions, Short-faced Bears, and Giant Ground Sloths, along with many other ice age species.
The lower reaches of the Tuolumne River cannot be mistaken for a world class whitewater rafting locale (you have to go upstream for that), but it can present unique challenges to amateur canoeists like myself. There are thickets of willow and cottonwood trees along the banks, and sudden turns in the river course can drive boats into a maze of branches. We had half a dozen swampings that usually happened when both canoeists ducked in the same direction as they went into the thickets. No one was hurt, but it can be momentarily terrifying.
In some places the river was constricted to where it was only a few feet wide, and the water flowed very fast. If you look at the canoe above, you can see how fast it's plowing through the water as the people oared furiously to avoid the thicket just below. The water whipped them in a circle into a back eddy.
There were also hazards caused by fallen trees. Some of them reached almost across the river, and the one above occurred just after a fast-moving chute. Being short (which I'm not!) has advantages in such situations. The Trust folks put a premium on safety. You can see that everyone had a personal flotation device, and leaders were stationed at critical points in the difficult passages to help guide boats through.
We've abused our rivers. Gold dredges did incalculable damage to this stretch of the river by ripping out the riparian vegetation and destroying the soils along the river floodplain. Miles of river habitat were destroyed by the search for a few suitcases of gold, but money seems to trump all. Over the decades the river has started to recover, but it will be many more years before the river can be truly healthy for salmon and all the other life forms that historically lived along the river (I looked for River Otters today, but unfortunately didn't see any). There are many other challenges, like the invasive hyacinth, a water plant that clogs river channels, pollution (why do we use rivers as a dumping ground?), and low flows related to the continuing drought in California (the water is warmer than it should be).
It was a marvelous day spent with people who are working hard to protect and rehabilitate this precious resource. Rivers are truly a gift, and they need to be cherished and protected. What rivers are near you, and what can you do to help?
People who live in Northern California or the Pacific Northwest might smile when I describe my Tuolumne as a river. Compared to the mighty rivers like the Columbia it is a middling stream. The thing is, it lies about that point in the northward journey in California where the rivers provide sufficient water for local use that it doesn't have to be imported from elsewhere (indeed, much of the water from the Tuolumne is exported to the Bay Area). We depend mostly on groundwater for domestic use, and the groundwater is replenished in part by the river. Most of the river goes to irrigation, but some is allowed to flow into the San Joaquin River and on to the ocean (not willingly, it should be noted; there are some who would just as soon use all of it).
The Tuolumne River begins high in the Sierra Nevada, flowing through Tuolumne Meadows in Yosemite National Park. It plunges into the Grand Canyon of the Tuolumne, a spectacular gorge that is as deep as that other canyon in Arizona. It is briefly stopped and diverted at Hetch Hetchy Reservoir, and then flows through a lesser-known gorge (unless you are a rafting enthusiast) to Don Pedro Reservoir. More water is siphoned off, but part of the river continues through the Sierra Nevada foothills and Mother Lode, and finally flows into the Great Valley, where it joins with the San Joaquin.
A swallow swings low over the river. |
What do they do? The Trust organizes river clean-ups, restoration of regions burned by the Rim Fire, and educational opportunities for children and adults. They also do political advocacy, as a voice for the river itself in the cacophony of agricultural and urban water interests. It's a great organization that deserves your support!
The river was alive with birds, bugs and amphibians. I glanced at a bug hovering a foot or so over the river, and it suddenly disappeared in the mouth of a swallow. The swallows accompanied us along the entire length of our journey. Maybe all the oars hitting the water was stirring up the bugs! I saw an old telephone pole in the distance, and immediately recognized the huge pile of sticks and random debris as an Osprey nest. Both parents were there, along with at least one chick (barely visible to the right of the birds in the picture above).
The Ospreys were not happy with the rafters and canoers below, and let them know in no uncertain terms. They relaxed when we floated by and headed downstream.The river is a perfect habitat for these grand birds. 90% or more of their diet is fish, and they are experts at landing feet-first in river to grab unwary ones floating near the surface.
Exposure of Valley Springs Formation along the Tuolumne River |
A bit further downstream there are exposures of the Mehrten Formation. It originated from volcanic mudflows related to the Cascades-style stratovolcanoes that once existed near the present day summit of the Sierra Nevada around 10 million years ago. Sediments within the unit have yielded an array of fossils including ancient camels and horses, giant tortoises, and strange 8 foot long saber-toothed salmon! Younger rocks above the Mehrten have given up Mammoths, Mastodons, Saber-tooth Cats, American Lions, Short-faced Bears, and Giant Ground Sloths, along with many other ice age species.
The lower reaches of the Tuolumne River cannot be mistaken for a world class whitewater rafting locale (you have to go upstream for that), but it can present unique challenges to amateur canoeists like myself. There are thickets of willow and cottonwood trees along the banks, and sudden turns in the river course can drive boats into a maze of branches. We had half a dozen swampings that usually happened when both canoeists ducked in the same direction as they went into the thickets. No one was hurt, but it can be momentarily terrifying.
In some places the river was constricted to where it was only a few feet wide, and the water flowed very fast. If you look at the canoe above, you can see how fast it's plowing through the water as the people oared furiously to avoid the thicket just below. The water whipped them in a circle into a back eddy.
We've abused our rivers. Gold dredges did incalculable damage to this stretch of the river by ripping out the riparian vegetation and destroying the soils along the river floodplain. Miles of river habitat were destroyed by the search for a few suitcases of gold, but money seems to trump all. Over the decades the river has started to recover, but it will be many more years before the river can be truly healthy for salmon and all the other life forms that historically lived along the river (I looked for River Otters today, but unfortunately didn't see any). There are many other challenges, like the invasive hyacinth, a water plant that clogs river channels, pollution (why do we use rivers as a dumping ground?), and low flows related to the continuing drought in California (the water is warmer than it should be).
It was a marvelous day spent with people who are working hard to protect and rehabilitate this precious resource. Rivers are truly a gift, and they need to be cherished and protected. What rivers are near you, and what can you do to help?
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