Saturday, October 31, 2009
Spooky Speleothems for a Saturday Scarefest
Watch out for that candy coma tonight, and don't run over any trick or treaters!
Thursday, October 29, 2009
Hosing Down the Mother Lode: Hydraulic Mining
The trick is to realize how much the topography of the Sierra Nevada has changed in 50 million years. If one were able to travel back to that era, a flight over the Mother Lode would have revealed a shoreline where the Central Valley is today. The shoreline would merge into swampy estuaries and lagoons, and every so few miles along the coast a large river would be flowing into the sea. Looking eastward would reveal a surprise: where the present Sierra Nevada Crest pierces the skyline there would be...no mountains! They had not yet risen (I hereby acknowledge that there is some fierce debate about the uplift history of the Sierra). Instead, the rivers would be flowing from sourcelands in central Nevada, or maybe even farther north and east (one has to wonder where the diamonds came from). The path of the rivers through the Sierra is fairly well established, and becomes more speculative as one travels farther east (see the map below).
Ash eruptions and lava flows covered parts of the Sierra Nevada while the mountains were rising, and rivers were diverted to their present-day channels. The rivers carved deep canyons as the mountains rose, isolating the patches of older stream gravels on the adjacent ridge tops.
It didn't take the forty-niners long to dig up and process all the gold-bearing gravels in the present-day rivers of the Mother Lode: they were pretty well played out by 1853. Some enterprising (i.e. hungry) miners started exploring the slopes and mountains above and soon found the Tertiary River Gravels, but there was a problem: they needed water to sift through the gold-bearing sediment, and water was not abundant on the mountain ridges.
Wednesday, October 28, 2009
Cave Bacon and Stalactites on Drugs: The Mother Lode Underground
Black Chasm is named for the deep cleft not far from the cavern entrance that drops 90 feet or so into a small lake. The lake extends at least another 60 feet downwards into the mountain. The chasm prevented the miners and other early explorers from exploring (and vandalizing) the more remote passages of the cave. As a consequence, the owners were able to develop the cave with a mind towards preserving the most pristine parts of the cave. They constructed stairwells and pathways across the chasm, with handrails preventing visitors from accessing and breaking the most fragile speleothems. The cave was opened for tours about 2001, and it quickly became my favorite choice for our geology field trips.
Tuesday, October 27, 2009
A Geology Professor Passes: Donald B. McIntyre
I've received word from Dr. Eric Grosfils at Pomona College that one of the professors from my days at Pomona has passed away. Dr. McIntyre was a truly unique teacher, challenging, sometimes frustrating, but an excellent professor. I look back and I realize I was not as ready for college as I thought I was when I arrived at Pomona in 1977. I had transferred from the local community college, and though I had done well enough, I was now entering one of the most highly regarded and challenging geology programs in the state. I felt like a fish out of water!
Dr. McIntyre taught a class on Global Tectonics. I thought was going to be told about divergent and convergent boundaries and evidence for continental drift and other basic "stuff". Instead, we were given the keys to the library, and a list of the original classic papers in plate tectonics to study so we could learn for ourselves not the basic facts, but what the original evidence was, what the detractors and opponents had to say, as a preparation to analyze the arguments in class. As a student in Dr. McIntyre's class, I had become, in essence, one of the researchers fighting the academic battles of the late sixties and early seventies. It was uncomfortable for me at the time, and yet a valuable life-changing lesson. Science isn't facts. Science is a process, a sometimes difficult process for gaining knowledge.
Dr. McIntyre could be almost imperious at times, and calling him "Donald" could earn a person a cold stare and silence. Yet most times, he was a warm and friendly person. He and his wife hosted a Christmas party for the students in the department every year I was there. It was a nice gesture for students who were sometimes several states or entire oceans away from their homes. I can remember him pulling a volume off the wall of his personal library to show me a passage on the history of mountain climbing in Scotland. The author had said that his climbing partner, one Donald McIntyre, if he ever fell off a cliff, would be licking the rocks on the way down to better identify them!
I worked in the department at Pomona for a couple of years while I decided the next step in my own educational journey. Serving as a laboratory and field assistant to Dr. McIntyre and the other professors at the school was as good an education as anything I ever learned in a classroom. I moved on in 1982. Dr. McIntyre retired and moved home to Scotland in 1989, and I occasionally heard of his activities through the school alumni announcements.
I finally was able to journey to Scotland in 2001, and my students and I were able to share a meal with Dr. McIntyre in Inverness. It was a wonderful evening. He was, as always, a gracious and polite conversationalist. It was good to see him again.
These are some of my personal remembrances of working with Dr. McIntyre. I invite you to see a bit more of his lifetime accomplishments at his website. He will be missed. The announcement from Pomona College follows:
Donald B. McIntyre, Professor Emeritus of Geology, died on October 21st in Scotland, where he had lived since retiring from the College in 1989. He was 86 years old.
A memorial service will be held on Friday, October 30, at 11:00 a.m. in St. John's Kirk, Perth, Scotland.
A native of Edinburgh, Professor McIntyre received B.Sc., Ph.D., and D.Sc. degrees from the University of Edinburgh and taught there before joining the Pomona faculty as an associate professor in 1954. The following year he succeeded A. O. Woodford as Department of Geology chair, a position he held for almost three decades. Professor McIntyre's research interests were diverse, and his achievements earned him numerous honors, among them Fulbright and Guggenheim fellowships. He was, his colleague Donald Zenger once wrote, "a scholar of the highest order."
Professor McIntyre was also a gifted teacher, winning two Wig awards here on campus and, in 1985, being named California Professor of the Year by the Council for the Advancement and Support of Education. In nominating him for the latter award, R. Stanton Hales noted: "It is known that one good question asked of McIntyre will earn at least two hours of personal instruction."
In lieu of flowers, members of the family have requested that donations in Professor McIntyre's honor be directed to one of two funds:
-- the Ewen McIntyre Upper Springland Fund; checks should be made out to the fund and sent to it c/o Ann McIntyre (17 Beaumont House, 15 N. St John's Place, Perth PH1 5SZ, Scotland UK). My understanding is that this fund helps support the home for the disabled where Donald and Ann's son, Ewen, currently resides.
-- the McIntyre Geology Fund at Pomona College (also called the Donald B. McIntyre-H. Stanton Hill Geology Fund), established in Donald's honor by H. Stanton Hill ('33) and Mary C. Hill in 1987; gifts/contributions intended for this fund can be sent to Pomona College, c/o Don Pattison, Office of Donor Relations, 550 North College Avenue, Claremont, CA 91711. In his remarks Stanton Hill directs that "this fund will be for the benefit of the students taught by Donald's colleagues and successors."
In addition, if anyone would like to share personal recollections of Professor McIntyre with his family and does not wish to send them to Ann directly, we would be pleased to receive, collate, and forward them along (please send such comments via email by December 1st, subject "Donald McIntyre", to https://webmail.yosemite.edu/owa/redir.aspx?C=4f27de7267174b68955d4b5890d81da5&URL=mailto%3aegrosfils%40pomona.edu). In a future communication, the department will also discuss developing plans for honoring Professor McIntyre at our annual alumni dinner, scheduled this year for the evening of February 17th, 2010.
The loss of such a highly regarded and cherished member of our community is never easy, and our thoughts are with Professor McIntyre's family in these difficult times.
Monday, October 26, 2009
So, What's Wrong With a Bit of Arsenic, Mercury and Sulfuric Acid in Your Drinking Water?
Sunday, October 25, 2009
Powder Monkeys and Dead Canaries: The Underground History of California's Mother Lode
We explored Highway 49 from Sutter Creek to Columbia, one of the richest sections of the Mother Lode. Part of the trip was an exploration of the Sutter Creek Mine (the Lincoln Project), which offers tours of part of the underground workings of this off and on gold prospect.
The picture above is the entrance to the mine shaft. The white cylinder on top of the opening is the ventilation system that keeps fresh air flowing through the mine.
We were taken by modified jeeps about a quarter of a mile into the mine. Unlike most of the Mother Lode mines, the Sutter Creek operation is fairly horizontal. It is just a bit eerie to leave the daylight behind and to go plunging into the darkness. The ventilation system is quite noisy. One of the people on the tour (not one of my students, I'm glad to say) pretty much lost it and had to be taken back out (she was not aware that the tour was an underground tour).
Saturday, October 24, 2009
Light a Candle in the Darkness: Volunteering for Science in Your Community
I noticed some of my comic strips were running a theme of volunteerism this week. Well, now my blog is too (and this would also by my contribution to this month's Accretionary Wedge)...
Here in California, K-12 education is in pretty much a chaotic mess, and our children are being shortchanged in the worst way. Class size is growing, budgets are getting slashed, and some of our best teachers are being fired. These are bleak times, and our community college system is no better off. But I am proud of what my colleagues at Modesto Junior College are doing. You can read the story here, but in short we are bringing fifth graders onto our campus every other Friday to give them an experience in science and to introduce them to our college campus. Most of our division (biology, chemistry, physics and earth sciences) is volunteering to make the program a success. From the article:
And...these kids are a lot of fun, too. Full of energy and enthusiasm! Contact me if you would like more info on how we set up the program (hayesg at mjc dot edu).
About 60 students watched and performed experiments as part of MJC's Science Educational Encounters for Kids. Every second and fourth Friday of the month, fifth-graders converge on campus for a science lecture and then two 45-minute labs.
"We are drawing members of the community into the college. Some of these students maybe don't think college is a possibility, and we want to show them this is their community college," said Brian Sanders, dean of MJC's science, math and engineering division.
"Activities are a blend of fun and interest with real science," Sanders said. "We're not just playing with bubbles. We're matching the labs with the state's fifth-grade science standards."
Thursday, October 22, 2009
The Airliner Chronicles: Epicenter of a Geological Education
For my thesis, I was looking for evidence of Holocene faulting in the Sierra Nevada/Great Basin Boundary Zone in the area around the Sweetwater Mountains and Antelope Valley. The West Walker River flows through the area, on its way to evaporate in the sump of Walker Lake, a remnant of Pleistocene Lake Lahontan.
Some of my relatives had a house in Walker, California, that served as my base camp for the summers that I spent exploring the region (Walker is the village in the lower half of the photo; the house is one of those on the river just left of center). As can be seen in the photo above, the West Walker emerges from a deep canyon carved in typical Sierra Nevada granites, and forms a modified alluvial fan at the south end of Antelope Valley, a deep fault graben marking the edge of the Basin and Range Province. The bank of the West Walker River served as a wonderful outdoor lab on hydrological processes. Over a 15 year period I was able to monitor drought conditions, floods, bank erosion, and riparian vegetation changes. I learned a great deal, but there was nothing in my experience on the river to compare with the events of New Years Day, 1997.
For those of you who lived in California or western Nevada at the time, the floods of 1997 will be remembered for a long time. A record snowpack coated the Sierra Nevada, but a Pineapple Express, a warm tropical storm out of the Pacific, took aim at Central California. Precipitation amounts in a two day period reached as much of three feet, mostly falling as warm rain on the snowpack. Record flows were recorded on numerous rivers, but I don't think any of floods smashed the old records the way the West Walker did...until 1997, no flood had ever exceeded 6,800 cubic feet per second. On January 2, 1997, the river hit 12,500 cfs. This is an estimated 500 year flood (a one in 500 chance of occurring in any one year).
The effects on the little village and surrounding region were profound, to say the least. Highway 395, the primary north-south artery between Reno and the Los Angeles region, was simply erased in the ten miles upstream of Walker. The ripped up road fragments, granite boulders, and uprooted trees became battering rams that pounded the unprotected hamlet of 500 or so people. Numerous houses, cabins and businesses were washed away. Much of the floodplain adjacent to the river channel was buried under several feet of gravel and cobbles, and the original river course had been split into two or three separate channels. Flooding in Reno and Carson City tied up emergency personnel, so the people of Walker were left to their own devices, and the hard work of the handful of highway patrol officers and county sheriffs in the area. Eventually a helicopter was brought in to rescue some stranded motorists. There weren't any television cameras recording the drama; they were too busy elsewhere.
I was not there to see the worst of it. I knew from the news reports that terrible things must be happening up there. It was about two days before we found a route into town, and the property was a mess. Against all odds, the house on the river survived the onslaught. Knowing the odds of a flood, my relatives had built an earthen berm around the house, almost like a fortress wall. The river had flowed full force into the berm, and was in the process of undercutting the foundation when a large pine got wedged into the opening, diverting the flow to the south (and eventually burying their truck in the mud). Their doors even held back the mud, and they might have been ok...except for the cat-door. Mud and silt flooded into the house to a depth of a foot or two. There would be a lot of cleaning up to do in coming months. Thankfully the relatives had flood insurance.
The following month had only one cold storm, and that February was one of the driest on record. No one minded. Clean up went on, and eventually the Army Corps of Engineers decided they wanted to put the river back where it used to be. This was an impressive process to watch. They had really big bulldozers to clear the old channel of debris, and I was sitting on the riverbank the day they made the cut that diverted the prodigal river back where it was supposed to be. We cheered as the river came back home...
After that flood, my relatives decided they had other priorities for their lives and sold the house. The new buyer found out that the legal floodplain level was now two feet higher than it had once been, and the house was now out of compliance. He solved the problem by taking the entire house and lifting it up eight feet and inserting a garage and basement underneath. I didn't recognize it the next time I came through town.
Do you have a good flood story?
Wednesday, October 21, 2009
Senator McCain joins Governor Jindal in Geologic Ignorance
Maybe McCain doesn't like that the money is spent under the auspices of the Department of Homeland Security, but the statement does reveal some appalling ignorance. The region around Memphis (and New Madrid, MO) was shaken by three massive earthquakes in 1811-12. It is one of the more dangerous seismic zones in the country that isn't named California, Alaska or Washington. Unfortunately, it is also one of the most enigmatic, being in the interior of a lithospheric plate, meaning there are no obvious reasons for earthquakes to be happening there. What is also not well-understood is the recurrence interval; when will the next large earthquakes strike? We don't know, hence the justification for studying "seismic activity".
I dunno. It seems to me that "homeland security" means something along the lines of keeping the populace safe from harm, whether the cause is "terrorism", or from natural disasters. I don't usually blog politics, but this is not smart politics.
Tuesday, October 20, 2009
The Airliner Chronicles: Crater Lake
Crater Lake is one of America's crown jewels, a feature so unique that it was one of the earliest National Parks to be established, in 1902. Despite the beauty and unique nature that led to the protection of the lake, the actual origin of the "crater" was not completely understood. Early assumptions were that the volcano had blown out the summit in a titanic explosion (though the local native Americans knew better; their ancestors saw it happen). It wasn't, exactly.
Crater Lake began as a composite volcano, an edifice of several overlapping cones that reached an elevation of between 10,000-11,000 feet, perhaps similar to the Three Sisters a bit farther to the north. The magma chamber was evolving in late Pleistocene time to a more silicic (and more explosive) condition. About 7,900 years ago, a large plug dome, Llao Rock erupted on the northeast flank of the volcano, heralding trouble. Two hundred years later, a massive single vent ash eruption shook the mountain. The ash cloud reached tens of miles into the sky and the entire summit region of the volcano destabilized and began to collapse inward. Vast amounts of hot ash burst out of the flanks of the mountain, burying local valleys 300 feet deep. By the time the eruption subsided, the entire summit region of the volcano, an area five to six miles across, had collapsed thousands of feet into the depleted magma chamber, forming a caldera. It had been the largest eruption in the Cascades within the last million years, releasing some 12 cubic miles of ash into the atmosphere, which covered a vast area of the western United States, even into British Columbia.
In the decades and centuries that followed, water began to accumulate in the basin, eventually filling it to a depth of 1,945 feet, the deepest lake in the United States, and the seventh deepest in the world. Post-collapse volcanism built several cones within the caldera, including Wizard Island, an andesite cinder cone that peeks about the water surface on the west side of the lake.
My picture was taken in the last moments of a miserable nine hour flight from Germany to San Francisco in 2007. My choice of black and white may seem...antiquated, but the forest was almost as blue as the lake in the original picture, so I took out the color and upped the contrast to bring out the lake a bit more.
Saturday, October 17, 2009
The Airliner Chronicles: My First Blog Series
"What a perfect situation for photographic excellence: small dirty scratched windows, absolutely no control over the route, inclement weather conditions, and jetwash distortions. Taking pictures from a commercial airliner is an exercise in futility. And yet, who of the geologists among you has been able to resist the impulse to try to take decent pictures of the geologic phenomena below you on those long, boring flights?"Air routes take you over terrain that you, and practically no one else in the world, can ever visit and the view is unique. The first picture of the series was one of the massive glaciers along the coast of Greenland, a place I would dearly love to see up close, but I just don't see it happening in the present circumstances of my life. So here they are, in the order that they originally appeared:
Picture of the Day - The Airliner Chronicles: A two minute break in the clouds on my first international flight allowed me a very brief glance at Greenland's glaciers
Picture of the Day - The Airliner Chronicles Part 2: A twilight flight out of Seattle yields a ghostly look at Mt. Rainier (click on the photo to enlarge it; I love the details revealed on the glaciers)
Picture of the Day: The Airliner Chronicles, Part 3: A look at Mt. St. Helens and the Toutle River Valley, site of the devastating 1980 debris avalanche and ash eruption.
Picture of the Day - The Airliner Chronicles Part 4 : Mt. Hood, one of the Cascades volcanoes and the tallest mountain in the state of Oregon
Picture of the Day - The Airliner Chronicles Part 5 : Mima Mounds in Washington. A marvelous geological mystery!
Picture of the Day - The Airliner Chronicles Part 6 : The Three Sisters, Cascade Volcanoes in Oregon
Picture of the Day - The Airliner Chronicles Part 7 : Revisiting Mt. Rainier, but in the daytime on a wonderfully clear summer day (again, the best view is to enlarge the photo by clicking on it)
Picture of the Day - The Airliner Chronicles Part 8 : The theme changed to glacial landscapes in Canada and Greenland. This photo may have been near Baffin Island, but good luck finding it on GoogleEarth
Picture of the Day - The Airliner Chronicles Part 9 : Breaking pack ice in the vicinity of Baffin Island, Canada
Picture of the Day - The Airliner Chronicles Part 10 : Kettles and deranged streams in northern Canada
Picture of the Day - The Airliner Chronicles Part 11 : A mystery picture!
Airliner Chronicles Follow-Up : A ground-level clue to the previous photo
We have a Winner! An explanation of the mystery shot: the photo shows a massive debris avalanche that destroyed a previous incarnation of the Mt. Shasta composite cone in northern California (kind of a nice view of Mt. Shasta, too)
Picture of the Day - The Airliner Chronicles Part 12 : A picture of one one of the more mysterious corners of Washington state, and one of the great detective stories of geological research, the Channeled Scablands
Picture of the Day - The Airliner Chronicles Another view of the remnants of one of the great floods of earth history: the Channeled Scablands
Picture of the Day - The Airliner Chronicles A flight over the Overthrust Belt near Banff National Park in Alberta, Canada
Picture of the Day - The Airliner Chronicles Back to Greenland, where a crevasse field generated a nice web discussion
Picture of the Day - The Airliner Chronicles : Some beautiful valley glaciers and a fjord in Greenland
The Return of the Airliner Chronicles: the Biggest Mountains on the Planet After a long hiatus I came back to the chronicles with a series of Hawaii shots. This one included the giant shields of the Big Island, and Diamond Head on Oahu
The Return of the Airliner Chronicles: the Biggest Mountains on the Planet, part 2 : A pair of photos showing some details of Mauna Kea on the Big Island of Hawaii
The Return of the Airliner Chronicles: When the Giants Begin to Die : A look at the summit of Haleakala on the Hawaiian island of Maui. It is a giant shield approaching the final stages of activity, miles from the hot spot on which it originated
I've got more in the photo files, so the Chronicles may make some future appearances. I'll update this post if it happens. Hope you enjoyed the journey!
Today's aerial is a close shot of Lassen Peak in northern California. Lassen was the most recent California volcano to erupt, with activity from 1914 to 1917 (the region is still a "hotbed" of geothermal activity). This extraordinarily large dacite plug dome is protected within the boundaries of Lassen Volcanic National Park. The main park highway can be seen snaking along the lower left hand side of the picture.
The Airliner Chronicles: Crater Lake : in honor of my colleagues at GSA this week.
The Return of the Airliner Chronicles: The San Andreas Fault in San Francisco. I finally get a good perspective on the fault zone!
The San Andreas fault in Southern California and the San Gabriel Mountains
A Flight Around the World's Highest Mountains: Mauna Kea and Mauna Loa: The clearest pictures I've ever managed to catch on the Big Island of the gigantic volcanoes
The Airliner Chronicles: The San Francisco Peninsula and the San Andreas Fault: Another flight from Oakland reveals another great view of the San Andreas Fault.
Friday, October 16, 2009
Has it Been That Long Already? Loma Prieta Earthquake 20 Years Ago Today
Andrew Alden at About.com: Geology and the Berkeley Seismological Laboratory are asking for our stories about the quake. In 1989 I was a brand-new instructor at Modesto Junior College, in my third semester. I taught classes in the old 1950's-era Science Building on our east campus, up on the second floor. I had all the modern teaching technology; there was a chalkboard, and two television monitors hung from the ceiling for showing those newfangled "videotape cassettes". The monitors also served as my decidedly low-tech seismometers. They shook noticeably during the smallest of earthquakes (most memorably during a class test on earthquakes; no one but me even noticed).
Losing Field Studies: Budget Crisis Continues in California
I'm not complaining exactly, because I still have a job, and a great many people have it far, far worse (although I did lose one teaching job this year already). I am simply saddened that our program is losing one of the best tools we have for training geology and teaching majors the core principles of the geosciences. It's one thing to describle rock types on a chalk board or in a box in the lab, and quite another to pick up rocks and minerals in the context of where they are found in nature. Teachers who have seen the things they talk about, whether volcanoes, faults, fossils, glaciers or whatever, will be better teachers. Geologists without field experiences are at a severe disadvantage in academic and employment settings.
For the time being, some of our more local field studies will go on in the fall and spring semesters, but I fear what is coming in the next year. Even if the economy improves it may be years before the state budget improves to an extent that will help the community college system. That somehow seems wrong, because it is the community colleges that are at the forefront of retraining workers during times of economic upheaval. But we are closing our doors to new students these days.
Wednesday, October 14, 2009
Tuesday, October 13, 2009
What a Way to Introduce Earth Science Week!
Well, we've kicked off Earth Science Week, and the theme of "Understanding Climate" in California with a whopper of a storm, the result of of the remnants of a super-typhoon in the Pacific meeting up with the strong jet stream. It slammed us pretty hard. In my own corner of the world in the Central Valley we had record rainfall for this date in October, breaking a fifty-year-old record (1.57 inches in Modesto, old record 0.97 inches) with wind gusts reaching 47 mph. My backyard rain gauge recorded even more, 1.90 inches, the second highest one-day rainfall total I have recorded in eighteen years. Trees and large branches are down all over town (including in my front yard), and the power has gone out several times over the course of the day. We are the arid spot of northern California; other places got a lot more: San Francisco Airport, 2.64 inches; Sacramento, 3.04 inches; Yosemite 3.43 inches. The big numbers are coming out of the Coast Ranges, which rise out of the surf along Big Sur and Santa Cruz to elevations of more than 4,000 feet: Venado 5.68 inches, Ben Lomond 10.58 inches, Three Peaks 14.30 inches, and at a recording station called Mining Ridge, just south of Big Sur, 19.45 inches (real-time data from the California Department of Water Resources Rainfall Maps)! I can barely imagine this kind of water coming from the sky.
It's probably a good moment to mention that a single day of incredible storminess is not "climate", it's "weather". Climate refers to the long-term pattern of precipitation and temperature that defines a region. A single storm does not have a direct bearing on our understanding of the nature and pace of climate change, but a pattern of increasing intensity or frequency over a period of years will shed some light on the issue. Especially if it has been predicted by climate modeling.
Sunday, October 11, 2009
The World is Going to End in 2012! Uh...Random Thoughts for Earth Science Week
Prius and Honda, Ichthyosaurs and Dolphins, and Mary Anning
It's Earth Science week, by the way! What will you be doing this week to promote an understanding of climate change?
Friday, October 9, 2009
Under the Volcano and Into the Abyss: Yosemite National Park
Yosemite National Park is the oldest "national" park in the United States, having been established by Congress and Abraham Lincoln in the midst of the Civil War as a protected reserve deeded to California. It became an official national park in 1890, third after Yellowstone and Sequoia. I did a short blog series (boog? bleeries?) on some of the less familiar sights that one-time visitors might miss if they spend all their time looking at Yosemite Falls or Half Dome. I recalled the series while discussing America's relationship to the national park system in the aftermath of the wonderful Ken Burns documentary "The National Parks: America's Greatest Idea". I have them (semi) organized below in the order that they appeared. I've also included a flurry of posts on some of the rock falls in the last year. If you are ever headed out to Yosemite, check out the NAGT geologic road guide to Yosemite Valley and the western Sierra foothills (the extended wood-pulp version can be ordered here).
Photo of the Day - Feeling Crushed? : this series started far from Yosemite, but rocks in the Coast Ranges are very much part of the story. Sierra granites originate from subduction of crust and subsequent melting of these rocks to form magma. We take a drive into the crust that would make Ms. Frizzle jealous
Journey to the Center of the Earth (well, the mantle at least) A brief look at chrome and mercury mining in the Coast Ranges, in the subduction zone rocks
Continuing Journey in the Earth - Taking the Time Machine When granites were forming under the future Sierra Nevada, dinosaurs and sea-going reptiles prowled the ancient land surfaces
Standing Underneath Volcanoes We arrive at Yosemite Valley and I describe the familiar scene from the Tunnel View, and explain the odd title
Touring the Underside of the Volcanoes, Part 2 How easy is it to visit the underside of a volcano? We find out, and what enclaves are in this post
Under the Volcano: Changing the Emphasis Taking a closer look at the Cathedral Rocks and the El Capitan granite that forms the impressive cliffs
Under the Volcano: Changing the Emphasis -Part 2 Another less familiar cliff is Sentinel Rock (see the second picture above), and the Sentinel granodiorite of which it is composed
Under the Volcano: Changing the Emphasis -Part 3 One of the unknown waterfalls in Yosemite is the rarely seen Sentinel Falls, on the south side of the valley across from Yosemite Falls
Exploring Yosemite, continued and the Rock of the Day A brief foray west of the park on a beautiful spring day, and a look at some of the older metamorphic rocks
Under the Volcano: Changing the Emphasis -Part 4 Who's heard of Lehamite Falls? Many park visitors ignore them, for they are overshadowed by nearby Yosemite Falls
Yosemite Falls: The Spectacle that Almost Wasn't Yosemite Falls are actually an aberration! They were once far more like Lehamite Falls in the previous post...I explain why
Under the Volcano: Changing the Emphasis -Part 5 A look at the Lost Arrow
Under the Volcano: Changing the Emphasis -Part 6 The highest unbroken waterfall in Yosemite is not named Yosemite! I describe it in this post
Under the Volcano: Changing the Emphasis -Part 7 Another little-known fall, the Royal Arch Cascades, behind the Ahwahnee Lodge
Under the Volcano: Changing the Emphasis -Part 8 Silver Strand Falls, another unknown waterfall
Under the Volcano: Changing the Emphasis -Part 9 Sometimes the familiar sights become transformed by different timing. Yosemite Falls at night, one of the few times we ever had the valley to ourselves
Staring into the Abyss - Yosemite as you (maybe) have never seen it We leave the valley floor and take in the view from the edge of the abyss at Taft Point
Staring into the Abyss #2 - Yosemite as you (maybe) have never seen it The Three Brothers from the rim, and Yosemite's largest historically recorded rockfall
Staring into the Abyss #3 - Yosemite as you (maybe) have never seen it Looking west from Taft Point towards the Cathedral Rocks, and what happened to Yosemite's meadows?
Staring into the Abyss #4 - Yosemite as you (maybe) have never seen it (and my 100th Post!) There are many domes in the vicinity of Yosemite Valley, and most did not form because of glaciation. A discussion of North Dome and Basket Dome, from Glacier Point
Staring up out of the Abyss: Check out this fire in Yosemite I link to one of the most extraordinary pictures I've ever seen of Yosemite. A fire was burning on the north rim, dropping embers into the valley. Spectacular!
Staring into the Abyss #5 - Yosemite as you (maybe) have never seen it Nevada and Vernal Falls from the Glacier Point area
Taking the High Ground: Yosemite as you (maybe) haven't seen it Climbing Sentinel Dome. A bit shorter than Half Dome, and a lot easier to climb!
Revisiting Yosemite Several weeks passed, and I made a few last posts before embarking on my journey through the Colorado Plateau. Yosemite Falls on a very windy day
An Alternate View of Upper Yosemite Falls My photo of Upper Yosemite Falls from an odd angle.
Is This the Most Beautiful Tree in the World? Several months passed, and several posts continued the tour of the valley floor; my favorite oak tree started a mini-meme
More Beautiful Trees... The tree meme grows...
Even More Beautiful Trees, and a Sequoia Story ...and grows some more!
How It Was: Yosemite Valley Yesterday... I visit the valley on a rainy November day, and watch Yosemite Falls go from dry to booming in a few short hours
Rocks fall in Yosemite? I had no idea that could happen! A discussion of rock falls in the valley; there was a lot going on in the valley in 2008-09!
Rocks fall in Yosemite: Park Service closes 1/3 of Curry Village More rock falls
During a Drought, What Do You Think About? In the midst of one of the worst drought years in decades, I ruminate on the incredible 1997 floods in Yosemite Valley and downstream
An Extraordinary Picture (at least for us Central Valley denizens) We find that Half Dome is visible from the Central Valley (on those rare clear days, anyway)
How it was: Yosemite Valley on a Saturday in April A springtime trip to the valley in the aftermath of a major rockfall. Several posts followed...
First Look: Ahwiyah Rock Fall in Yosemite A first look at the Ahwiyah Rock Fall from near Half Dome. The view of Yosemite changes forever!
Another Look: The Ahwiyah Slide in Yosemite Got as close as I could to the new rock fall (don't people usually run the other way?)
A Final Look (for now): The Ahwiyah Point Slide in Yosemite The dust settles...
The Ahwiyah Point Rockfall: the View I Wish I Had The National Park Service checks in with some great photos of the rockfall
Ahwiyah Point Rock Fall Update: Before and After Photos Doug Nelson provides a great view of the rockfall from Glacier Point
Geologic Change in Yosemite: Remembering the Happy Isles Slide of 1996 A look at the big slide behind Happy Isles...
Another Rock Fall in Yosemite ...and the next day, another fall takes place!
Ollie Hopnoodle's Haven of Bliss and America's Greatest Idea And we arrive at the most recent post on my favorite park.
I intend to continue some photo-essays on Yosemite National Park. I'll update this post as they appear. If you take the time to check them out, I thank you and hope you enjoy the series!
Thursday, October 8, 2009
Ollie Hopnoodle's Haven of Bliss and America's Greatest Idea
A favorite seasonal tradition for many people is a viewing of the movie "A Christmas Story", the adventure of Ralphie and his quest for a Red Ryder BB gun. Most people are unaware of a second film in the adventures of Ralphie that came out as a 1988 Disney TV movie: "Ollie Hopnoodle's Haven of Bliss". Jean Shepherd once again narrated the adventures based on his childhood in 1940's Indiana, with Ralphie's first summer job, and the family's traditional yearly vacation to a lake in Michigan, the Haven of Bliss resort. It has yet to be released on DVD, but if you get a chance, check it out. It's hilarious, and even touching at times.
Wednesday, October 7, 2009
Of Vooks and Blooks
I thought I heard a discussion of some weird new kind of "vook" on public radio the other day, and finally ran across a written account of video-book hybrids in this article in Salon.com. I can see the usefulness in such a monster if some kind of complicated process is being taught, but I am less enamoured of the idea if it is going to be a low-cost drama production. I get lots of that on the cable channels.
It reminded me of a discussion I had the other day with someone who doesn't want to be associated with the writing disaster that follows. We were talking about the nomenclature for the project I just finished on the Colorado Plateau. Over a year's time, the series of blogs had grown into a narrative with the length (if not the style) of a small book. What should such a thing be called?
We immediately thought of "blook" and congratulated ourselves on our creativity and originality but a quick google search confirmed the that term has existed since at least 2002. Oh well. Just the same we realized that people who write blooks would have to be called "blookers", and if the authors are German women, they would be "Frau Blookers" (frenzied neighing of horses breaks out*).
Our second choice for the name of a blog-book hybrid would be a "boog". I liked it, but a google search revealed that a boog had all kinds of dark and gross meanings related to nostrils and drugs. So that won't work so well, but so many things could have been right about the word. When we said we needed to "boogie", folks would think we were really cool and all, and not going home to chew on Cheetos and stare at a computer screen. The problem with "boogs", books written as a series of blog posts, is the lack of continuity and style. Such projects need the help of an editor or even an editorial board, a "boogie-board" as it were.
Maybe an interesting idea. It ultimately can't work though, because the authors of boogs would of course have to be called..."boogers".
Ok, back to geology...
*If you don't know this movie reference, you have to go study Mel Brooks and satires of old monster movies
Sunday, October 4, 2009
Do Big Earthquakes Cause Tremors Elsewhere?
With the spate of large earthquakes worldwide, some people have asked if large earthquakes can set off smaller earthquakes elsewhere. In short, the answer is yes, but the big earthquakes don't make other earthquakes; they may help trigger earthquakes in places where stresses are close to the breaking point anyway. These smaller quakes usually occur within a few hours of a major tremor. But there are some odd complications that are now being recognized.
Some new research, reported in NatureNews, suggests that large distant quakes can weaken other fault zones and cause activity months later. This assertion is supported by the fact that the period of 2005-2007 following the devastating magnitude 9 Sumatra-Andaman quake (the tsunami killed nearly a quarter of a million people) had the largest number of large earthquakes than any comparable period since the early 1900's.
The abstract for the research article can be found here (the entire article requires a fee). The full article: Taira, T., Silver, P. G., Niu, F. & Nadeau, R. M. (2009). Remote triggering of fault-strength changes on the San Andreas fault at Parkfield, Nature 461, 636-639.
The photos today show the San Andreas fault on the Carrizo Plains south of Parkfield, and the Landers fault in the Mojave Desert. The 1992 quake on the Landers fault (mag. 7.3) set off tremors at Parkfield months later.