Friday, December 30, 2011

Earthquakes in Flagstaff?

The city of Flagstaff sits among some of the most beautiful western scenery to be seen anywhere, with graceful Ponderosa pines and the San Francisco Mountain nearby (both shown above). But the Lake Mary fault is a potential hazard in this idyllic setting, that could unleash a 6.9 magnitude earthquake in the area. Other large quakes were felt in here in 1906, 1910, and 1912. Their magnitudes were 6.0 and 6.2.

Watch a five minute video with Dr. David Brumbaugh who explains many of the particulars about this Falgstaff geo-feature:

Map of the Lake Mary Fault system, courtesy of the Arizona Earthquake Information Center at Northern Arizona University

Friday, December 16, 2011

Trail of Time at Grand Canyon National Park Receives Award

Regular readers of this blog will remember a posting from October, 2010 when the world's largest geo-science exhibit was dedicated at Grand Canyon National Park. My blog posting on the Trail of Time  can be recovered and viewed here. This exhibit recently won an award from the National Association for Interpretation. You can read the official NPS release about the award here.

Here's to the Trail of Time at Grand Canyon!

Sunday, December 11, 2011

Back to the Antarctic - the 100th (and 75th) Anniversaries of the First Person to Reach the South Pole

Roald Amundsen and four others from Norway had been trekking across the Antarctic continent by sled and dog team for 54 days when they finally arrived at 90° south on December 14, 1911. Amundsen and his team were thus the first people to ever stand at the very bottom of the Earth! Wednesday marks the 100th anniversary of this exploration milestone and in honor of it, I am sharing some of my photographs from my stint at the South Pole Station in December/January, 1986, when the 75th Anniversary of Amundsen's feat was commemorated. In this portfolio you will also see images of McMurdo Station from the winter of 1986-87. At the South Pole Station on December 14, 1986 about 46 of the 64 persons stationed at the Pole that day went outside on a bright and sunny day and remembered Roald Amundsen, Robert Scott, and their men.

This is (or was?) the National Science Foundation headquarters at McMurdo Station in 1986. The flags of the original 13 Antarctic Treaty signees fly in front of the building. Antarctica is the only continent dedicated to science and peace.

A view of a "street" in old McMurdo Station. I am sure that the buildings here have now been replaced.

Playing hacky-sack in front of the church in McMurdo, January, 1987. A bit of Observatory Hill is visible in the right background.

Here is the entire McMurdo Station as viewed from the top of Observatory Hill in November, 1986. Note the frozen Ross Sea in the upper left. Scott's Discovery Hut (1902) is located on the small peninsula jutting out into the sea.

I volunteered to help various geologists conduct their research. Here I am (on the left) working a tool that drills through the sea ice. Yes, we are out to sea in this photograph and standing on frozen ocean, where the sea ice is about 10 feet thick. Once we drilled a hole in the ice, we dropped a coring device that hit the ocean bottom about 1,600 feet down and brought up whatever sediment had accumulated there over many thousands of years. This was research being conducted by Dr. Rob Dunbar, then of Rice University but now at Stanford.

An outdoor picnic at McMurdo Station, November, 1986.

On December 13, I received orders to report to the South Pole Station at 90° south. Here we are flying over the Shackleton Glacier (or was it the Beardmore?) with the Trans-Antarctic Mountains in the distance. These mountains are about 5,000 miles long and are a fantastic trove of earth history

Of course, the bottom of the world is upside down and when I walked off the C-130 airplane, this is what I saw. I'll turn the rest of the photographs "up-side down" so that you can see them better.

The old sign in front of the South Pole Station. Back in these days it was called USARP - the United States Antarctic Research Program. Now I believe it is called simply USAP - the United States Antarctic Program.

This is the main entrance to the old dome as it looked in December, 1986.

Here is the official 75th Anniversary photograph on December 14, 1986. We were commemorating the first arrival of Amundsen and his men at the South Pole on December 14, 1911. I am in the front row, third person on the right (light colored shirt beneath the jacket). We decided to hoist the Norwegian, British and American flags for the commemoration. Why not - Scott arrived only five weeks later and after 100 years, that is essentially the same time. I think Amundsen would agree that it's close enough.

I stepped out from the group photo to take one of my own in color

The galley crew made a cake for the occasion that shows the old South Pole Station on top of it. Nice!

This is a blurry photo taken of the group after we returned to inside the dome, with the baker kneeling in front of the cake below. It was dark in there and this was film photography, so that is why the photo is blurred.

A rousing celebration at the South Pole on Christmas Day, December 25, 1986. Even though a lot of work is performed at these stations, every day is a holiday at the South Pole. Temperature here a brisk -30° F.

The reason for my stint at the South Pole Station is that the Clean Air Facility (about 10 years old) was becoming buried in snow drifts and we were sent to hoist it up using pneumatic technology. Previous attempts in other southern summers had failed. The conditions were cold and windy. I saw a wind chill of -60° F, and the warmest it ever got was -6° F. Not cold you say, but this was summer time!

After three weeks, we had the building up on steel girders and were ready to lock it in place. The snow accumulated here at about one foot per year, so all buildings are subject to being buried.

After only 20 minutes in the cold, one's beard begins to get heavy

There was a "warm-up" hut located nearby with hot coffee and soup and most of us needed to go inside at least every 30 minutes - even with our Antarctic clothing

The glacial ice "drifts" over the pole of the earth at about 10 meters per year. This means that the official marker must be moved each year. You might see a small marker located between the two poles on the sign - this was the exact pole position on January 1, 1987. My feet frame the view (below).

The sign shows that the land at the South Pole is very close to sea level but that the ice thickness is about 9,000 feet. Not only is it cold here but there is not much oxygen!

In December of 2002, I returned to the South Pole with a group of visitors. We took an eight hour flight (with a refueling stop on the ice along the way) to the Pole from a camp we were staying at.

This is the view about half way to the pole. 90% of the planets fresh water is tied up in Antarctic ice!

At this time, a new South Pole station was being built near the old dome.

The material for this station was brought in overland from McMurdo Station on an Ice Highway. Read about it here. This station is designed so that it can be uplifted as the snow begins to pile up around its base.

Research in Antarctica continues today and to read a recent article about a sub-glacial mountain range on the White Continent, click here. And to read the blog of Dr. Ed Stump who has conducted 40 years of research in the Trans-Antarctic Mountains, click here.

Monday, November 28, 2011

Wonders of Geology - A New and Stunning iPad Download from Michael Collier

A Michael Collier photograph of the Teton Mountains

When most people think of the science of geology, they likely do not conjure up thoughts that excite the senses or exude images of great beauty. How odd because to geologists themselves, their chosen field is nothing if not exciting and beautiful! I know of geologists who routinely gasp with pleasure, losing their breath when they come over a rise and see what is laid out before them on the landscape. If you have ever wanted to enter a realm of earthly magic, do so through the eyes of an earth scientist who will show you the everyday things in whole new light. Geology holds wonder for everyone, if only we could access its jargon and complexities.

Say no more - for this coming Friday on December 2, Mikaya Press unveils a brand new download created by geologist, photographer, and small aircraft pilot Michael Collier. It is called "Wonders of Geology" - An Aerial View of America's Mountains and is sure to be one of the most modern and easy ways to access the arcane but ultimately rewarding world of our planet's geology. I had a chance to preview the download earlier this month and can share some of what I learned from the experience.

First, an acknowledgment that I know Michael Collier very well. He was my next-door neighbor for 20 years and being both "lovers-of-all-things-earth", we have a lot in common. But our connection does not warrant me to write a review of this new learning tool. What does is Collier's unique tri-part combination of being a geologist, a photographer and a pilot that make "Wonders of Geology" a truly breathtaking tour of North America's mountains. There is perhaps no better way to see and learn about mountains unless you become a geologist, a photographer and a pilot, all in the same life.

In "Wonders of Geology", we learn how mountain chains were created by uplift and see how they have been sculpted by erosion and carved by glaciers. The download would be well worth the $12.95 asking price even if it only included Michael's 240 photographs. But the program is also well-illustrated with numerous diagrams, maps, and figures developed by Tasa Graphics in Taos, New Mexico. These are used to blend what you see in the photographs and hear in Michael's own voice-overs, teaming together to make the learning pleasurable and easy. There are various "chapters" that can be easily navigated to from a prompt on the bottom of the screen.

There are few downsides. At this time it is only available to owners of Apple's iPad platform. (Having been an Apple geek myself since day 1, this does not present a problem for me and I can heartily endorse any Apple product for the sheer sense of beauty each of their inventions contains). Geologists themselves will know most of the subject matter in the program and it is not meant to be anything more than an introduction to the "wonders of geology". But even if you are a professional already, you could easily utilize this when teaching family or friends about your world view. It is an excellent way to grasp difficult concepts in a meaningful and fruitful way.

Here is a sampling of some of Collier's magnificent photographs in "Wonders of Geology". The captions here are mine but each photograph is part of a lovely narrative presented in "Wonders of Geology".

The Sheep Mountain anticline in Wyoming. This fantastic warp in the earth's strata was formed between 70 and 60 million years ago during the Laramide Orogeny. When these strata were buckled upwards, they were still many miles below the earth's surface but more recent erosion (and stunning early morning light) accentuate these mulit-colored strata. Such are the views that Michael Collier will share with you as he flies his small Cessna airplane over these features.

Mt. Stanford in the Sierra Nevada of California. John Muir called the Sierra the "Range of Light" and Collier definitely has captured the essence of this moniker.

Closer to home in Flagstaff, Arizona and a view of the southern slopes of Mt. Elden, a dacite dome volcano that erupted in the San Francisco Volcanic Field about 500,000 years ago. The three obvious lobes formed when very viscous lava (dacite) was extruded on the top of the volcano. As the lava piled up, gravity grabbed a hold of it causing it to cascade very slowly downslope. This aerial view of the lava lobes is the best I have ever seen and allows for quick comprehension of the earth processes that created them.

Death Valley plays a prominent role in "Wonders of Geology". Here is a view of Split Mountain, a volcanic cinder cone that erupted along a fault line. After the cone had formed, the fault moved again and split the volcano. See the diagram below with accompanying graphics to explain this concept.

Spilt Mountain, Death Valley, California.

You can watch a preview of the program at this url: I found this program worthwhile and if you already own an iPad and are a geologist you have to have this to share with your friends and family over the holidays. If you are a photographer you will love Collier's works of art. And if you are a pilot, you'll find this useful as well to know what you are looking at from above.

Wednesday, November 23, 2011

Geology of the Spur Cross Ranch

On Saturday, November 12, I led a group of 27 avocational archaeologists from the Desert Foothills Chapter of the Arizona Archaeological Society on a geology field trip to the Spur Cross Ranch Conservation Area. The park is one of the gems in the Maricopa County Regional Park System and was established in 2001 to encompass 2,154 splendid acres of the northern Sonoran Desert. Many "arch" sites are located within the preserve and the members of the club wanted to learn more about the geological resources here. I had previously given two geology lectures to the group, in my role as an Arizona Road Scholar. This program is a part of the Arizona Humanities Council, whose mission is "to build a just and civil society by creating opportunities to explore our shared human experiences through discussion, learning and reflection". The AHC is one of the best programs I know of in the state of Arizona.

The history of the preservation effort of the Spur Cross Ranch is an interesting one but much too convoluted to go into detail here. In short, developers bought an old cattle ranch in the 1990's with the intent of creating a mini-city on the north fringes of Phoenix. This was during the boom-boom days of the Arizona housing frenzy and it looked like a done deal. Not so fast, said the citizens of Cave Creek, a sleepy little hamlet that started life as a mining camp in the 1870's. They voted for a sales tax that paid for the land sparing it from development. With 80% of the town voting in the election, 77% of them voted in favor of the 0.5%, 20-year sales tax. The cost of the bond will be paid off by next June (eight years early) and a story can be read here that details the history of the acquisition fight. For a more jaded view of the preservation effort, you can read it here.

After I gave a brief overview of the geology at the trailhead, we hiked up Cottonwood Wash. The geology begins with its location in the north part of the Phoenix basin, specifically at the junction of Arizona's Transition Zone and the Basin and Range. Many mine shafts are located here and recall the glory days of prospecting when Arizona was seemingly as far away as Mongolia. Miners were lucky in some instances in finding gold and silver in the area. These elements would have held no value to ancestral peoples.

My gracious hostess, Paddi Mazoli, at the entrance to the Nutcracker Mine in the Spur Cross area. Two groups of rocks are found here - an older sequence of Precambrian meta-sediments and meta-volcanics, and much younger basalt lava flows and sediments that are Cenozoic in age. Paleozoic and Mesozoic sedimentary rocks were likely here at one time but have been removed by erosion.

**2019 Update** - Thomas McGuire, who is writing a book about the Spur Cross Ranch geology, sent me a recent photo of the Nutcracker Mine entrance. A few years ago, a rockfall closed off the entrance. I attach his photo of the mine entrance before (2009 photo) and after ("a few years ago).

In the washes of the area, most of the durable rock types can be found. These make for a colorful mélange that are striking in their appearance. By far though, the most striking outcrops involve the lava flows of the Hickey Formation that cap Skull Mesa (shown here) and New River Mesa to the west. These flows were emplaced about 14.8 million years ago when the valley floor was not as dissected.

Skull Mesa located northeast of the Spur Cross Ranch Conservation Area is capped by Hickey basalt that has been dated at 14.8 Ma. The whitish outcrops beneath the mesa top belong to the Chalk Canyon Formation, a lacustrine and fluvial deposit that had yielded Arizona's oldest mammal fossil, an oreodont.

Artists reconstruction of an oredont, an example of which was found in the Chalk Canyon Formation near Cave Creek, Arizona, when this area held an ancient lake some 22 Ma

The Hickey basalt lava flows once continued much farther to the south after they were erupted, but more recent faulting disrupted the flow ends. This is evident everywhere in the northern parts of the Phoenix basin. Here from near the center of Cave Creek Town, you can see the same flows that were once attached to Skull Mesa. They have been faulted such that the former tops of the lava flows are now slopes on the right side (north end) of the hills. As the Phoenix basin was extended, the flows slipped downward and became tilted. Geology in action!

Petroglyphs abound in the area as do these boulders of Hickey basalt

Note this basalt boulder which has been rolled in a flood once or twice in Cave Creek! The white calcium ring that was once sitting horizontally in a pool of water has been moved such that it is now vertical on the rock. A new calcium ring has begun to form at the base in its present position.

It is a lovely area and a big thanks to the members of the Desert Foothills Chapter of AAS. They were most welcoming and a great group to hike with. Also, a big thank you to the citizens of Cave Creek who temporarily taxed themselves so that these 2,154 acres would be preserved in perpetuity for all Arizonans. Your forward thinking is very much appreciated by this Flagstaff boy.

Rainbow over Cave Creek, November 12, 2011

Monday, November 21, 2011

More Photo's From The Toroweap Geology Trip

Alice sent along some more photo's from our Toroweap field trip this morning. Thank you Alice!

In this shot we can clearly see the offset on the Toroweap Fault which runs across the photo behind the shadowed cliff on the left. It is the Esplanade Platform on the upthrown side of the fault, while the bench in the center distance is the same feature faulted lower to the west. About 500 feet of offset has been measured on the fault here. Note the cinder cone on the lip of the downthrown block. Magma likely utilized the fault line as a conduit to the surface. Note also the dip towards the photographer on the downthrown block, which rotated as it was lowered.

Here is an example of weathering on the Esplanade surface. The Esplanade Sandstone began life on the shores of a Permian sea, located not too far west of this locality. Sand was deposited on this coastal plain in low-lying dune fields. Subsequent burial put it into silent preservation for hundreds of millions of years and groundwater left a calcium cement between the quartz grains. Upon exposure, rainwater reacted with and dissolved the calcium cement such that hollows like these were formed. Although Alice took this photo to highlight the beautiful heart shape of the depression, she also had an eye for the process that creates these features.

This is Vulcan's Throne after we descended its top and hiked to another cone north of it. The view is to the south and behind the Throne is a 3,000 drop down to the Colorado River. Note the white playa lake deposits that accumulated at the intersection of the cone (erupted about 71,000 years ago) and the scarp of the Toroweap Fault (with movement mostly before the cone was emplaced - there is a small saddle on the east side of the cone that likely represents post-eruption movement on the fault).

Toroweap is an awesome place!