Tuesday, May 1, 2012

Epilogue of Yellowstone

Yellowstone National Park contains world renowned: geothermal features, volcanic past, over 50 species of mammals, 311 recorded species of birds, and the devastating fire of 1988. Out of the 3 million visitors that travel to Yellowstone each year, many will leave the park without see the worlds largest aggregation of upright petrified trees, or the unique sedimentary rock formations of hoodoos

The two main attractions are:

Volcano activity

USGS Geologic Map of the lava flows overlaying with the faults.
Examples are: pumice breccia on Purple Mountain, Obsidian CliffBalsalt columns at Overhanging Cliff, tuff at Virginia Cascade (that is undergoing weathering!), and the famous caldera of Yellowstone.

Geothermal features
Diagram of the different types of geothermal features found in Yellowstone. Yellowstone is the most concentrated location of geothermal activity with 10,000 thermal features and 300 geysers!

Grand Canyon of Yellowstone is another main tourist attraction, with over eight different viewing spots along the Yellowstone River. The two major waterfalls are Lower Falls and Upper Falls. 
Aerial view of Upper and Lower Falls in 1974.
Yellowstone River contains: meandering channels, alluvial deposits, waterfalls, eroding bedrock, and knick points. This perennial river is part of a larger dendritic drainage pattern, starting in North Dakota. Observing the map of the drainage basin, there are three tributaries with Yellowstone River being the largest. 

Section of Missouri River Basin with Yellowstone River at the main tributary. Yellowstone National Park is highlighted in yellow.

Ten years from now Yellowstone River will continue eroding away the canyon, picking up the softer rhyolite in the dissolved and suspended load. Resistant rock, in this case hard rhyolite, will collapse as undercuts crave out the less resistant rock. Scientists speculate an ancient geyser basin is responsible for the softening of the rhyolite (chemical weathering), that in turn help create the waterfalls. Both Upper and Lower Falls will retreat upstream, showing the knick points are temporary. Yellowstone River occupies a V-shaped valley, exposing the process of fluvial erosion and perhaps a flood by glacial dam breaking over 14,000 years ago.

Yellostone's 1988 fire that destroyed one-third of Yellowstone could happen again in a hundred years! 
Over 25,000 firefighters participated to control the flames that lasted from early July to October in 1988.

The likelihood that a fire of the 1988's size will happen now is slim. There is still vegetation growing, and not the quantities that it needs to start, and maintain a fire of that magnitude. Majority of Yellowstone, eighty percent, is composed of forest. Lodgepole pine make up the forests. These trees have brittle needles due to the less around of precipitation; retaining as much moisture as possible.  The soil of Yellowstone is mostly weathered rhyolite bedrock formed from lava flows that filled the caldera. New vegetation in an arid landscape, pine trees, soil that wicks away moisture is a great recipe for a wild fire. 

Rhyolite is the main soil at Yellowstone, exposing Yellowstone's violent past.
Rhyolite is not permeable and a low nutrient content. Geoscientists studying sediment cores say fires have increased in frequency over the past 9,000 years, compared to the collection of over 17,000 year history. If the carbon dioxide continues to increase in our ozone, causing temperatures to rise, we may see more frequent fires in Yellowstone. Vistors here in 1988 are taking photos of the recent fire. Evidence from the petrified forests (chemical weathering by concentrated silica in the groundwater.) in Yellowstone are dated back to the Eocene period. Where the climate was around 7-12 degrees warmer than it is today. Scientists discovered the petrified trees were types that require wetter and warmer climate. Examples of petrified trees in Yellowstone are: Chestnut, Magnolia, Sycamore and Willow. Evidence that vegetation will thrive with several decades of uninterrupted growth (currently happening) and wet years (what the climate may be in 100 years) a massive fire may burn Yellowstone again.

Satellite image of Yellowstone's 1988 fire.

Rhyolite magma is moving upward towards to two domes. 
In a thousand years, the two resurgent domes in Yellowstone will have grown to concerning levels. As my previous blog discussed, earthquake swarms can have up to two thousand earthquakes in a span of four months! Faults can generate earthquakes, which there are many faults around the caldera. Earthquakes can: create geothermal explosions, cause debris flows, flooding, and damage roads. Importantly, earthquakes trigger compression of the plates near the fault lines, increasing the size of the resurgent domes. 

Looking northwest Mallard Lake Dome and the gaben that formed along its axis.
760,00 years passed between the first super-eurption to the second one, and 650,000 years passed since the second, and third eruption. It has been 640,000 years since the last Yellowstone eruption. Scientists hypothesize that we are owe for our next big eruption. Yet, Yellowstone's hot spot is continuing to move underneath the North American Plate traveling southwestward, perhaps changing the future of Yellowstone next eruption!

Generalized cross section of the crust underYellowstone. Expressing the ring faults where a lot of the earthquakes and growth of the domes occur.

One key factor in the future of Yellowstone are the tourists. Yellowstone is a hot spot for vacations. People bring in pollution, trash, food and congestion to the once mysterious place. The interaction between the wildlife and visitors have transformed over the century. So will the geology and the physical geography of Yellowstone National Park!

My Ma, and I depressed at the Leaving Yellowstone National Park sign.


Tuesday, April 10, 2012

Canarystone Under Pressure

Yellowstone Lower Falls, Yellowstone Grand Canyon.
Climate at Yellowstone can be classified as BSk under Koppen's system. B is the major climate group, a dry climate. When evaporation exceeds precipitation results in a dry climate. K stands for midlatitude with a steppe. This is the same climate at Denver, CO. Yet they are quite vast in weather, the topography places a key role in the weather at Yellowstone. For a detailed chart of the climate and average precipitation click here.
Climate of Yellowstone over 30 years

The video below describes a unique process at Yellowstone. The geothermal heat underneath the park actually makes the winters much harsher.

The nights in Yellowstone can get brutal for the wild animals living in the caldera. The daytime valley breeze effect happens during the day when the warm land carries into the high altitudes of Yellowstone and during the nighttime the mountain diurnal flows bring the cold air to the valley of the caldera. Many time this process creates valley fog. Add this with the geothermal, hot springs in the caldera and you get heavy snow, fog, and vast cloud formations. Radiation fog can be found all around Yellowstone in the early morning and late evening. 

Causes by the cool air coming down from the mountains with the warm earth above the geothermal soils. As well as Yellowstone Lake has evaporation fog as the bottom of the lake has a direct hole to intense temperatures of the hot springs underneath. Stratus nebulosus clouds form in stable air mass conditions.

  • http://www.wrcc.dri.edu/cgi-bin/cliMAIN.pl?wy990
  • BBC's "Yellowstone Battle for Life"
  • http://radar.weather.gov/ridge/radar.php?rid=riw&product=N0R&overlay=11101111&loop=no

Friday, March 9, 2012

Wx is The Secret Rx in Yellowstone

Mammoth Hot Springs, Obsidian Cliff and, Mary Bay a few of the unique geological formations created by weathering at Yellowstone National Park.
Shrugs going through chemical weathering at Mammoth Hot Springs.
Mammoth Hot Springs composes of the most extensive system of actively forming hot springs terraces within the park. These terraces are made up of travertine: dissolution of limestone (or calcium carbonate) deposits from thermal water. Limestone lives in the fault lines along Mammoth Hot Springs, which draw conclusions of how the network of hot springs formed over vast topography.

Dead Lodgepole Pines in Mammoth Springs by Wolfgang Wander

The precipitation of limestone propels the odor of rotten eggs. Photosynthetic bacteria actively breaking down the hydrogen sulfide in the water and creating Calcium Carbonate. The bacteria produce vibrate colors of yellows, oranges and browns as seen in the ionic images of Yellowstone's geothermal features. Prolific Calcium Carbonate is actually suffocating Lodgepole Pine Trees, found all around Mammoth Hot Springs.
The Southern view of Obsidian Cliff by Joseph Iddings 1888. 
Eleven miles south of Mammoth Hot Springs is Obsidian Cliff. The USGS Map of Geological Yellowstone indicates the unique rhyolite formations. Obsidian rock forms from rapidly cooling lava that has no crystallization, resulting in a dark volcanic glass. The photo above shows columnar joints, lava flow cooled and contracted as a single unit, in a rapid pace. The joints weaken the rock for erosion to occur. Add steep slope to form a talus slope of scree. Obsidian occurs naturally as small rocks, making Obsidian Cliff rare as its vast expansion of the volcanic glass. Archeological artifacts show many cultures used Obsidian for tools, such as Native Americans making arrowheads.
Enlarged map of the geological formations of Obsidian Cliff. The (Qpr) amaranth formation is the plateau and the pastel yellowstone (Qs) detrital deposits.

Hydrothermal explosion that consists of Mary Bay the northern part of Yellowstone Lake. A crater produced by pressure of the magma, an earthquake or a tsunami. All requiring a great amount of force and pressure. 

(A) Confined pressure (B) water Table drops, which fragments the overlying rock and propels it upward (C) explosion of mud, steam, and water until a drop in confining pressure and steam lessened (D) a crater remains and fills with water.

A soil profile of Mary Bay crater expresses a calcification process of either andisol or aridisol soil types. The profile clarifies two main explosions took place by the varying volcanic arc deposits. Mary Bay crater has an active vent discharging thermal water rich in clay minerals. 
Soil profile of Mary Bay, Yellowstone Lake (Click to enlarge)

  • http://ngmdb.usgs.gov/ngm-bin/ILView.pl?sid=9475_1.sid&vtype=b&sfact=1.5
  • http://www.nps.gov/yell/planyourvisit/upload/Yell250.pdf
  • http://www.pbase.com/wwcsig/yslandscape
  • http://www.nps.gov/history/history/online_books/geology/publications/bul/1444/intro.htm

Sunday, February 12, 2012

Living Yellowstone

To begin to explain the unique characteristics of Yellowstone I chose to create a trailer for this entry. For me, discovering why Yellowstone is what we know today was as exciting as watching a summer “blockbuster” movie. 

Geysers, springs and hotspots are evidence that Yellowstone is an active volcano and will erupt in the future! Yellowstone's largest eruption, Lava Creek eruption, over 640,000 years ago. A 1,000 times the volume of Mount St. Helen's eruption in 1980. The Lava Creek erupted with violent force that blasted volcanic ash across more than 15 states.  After the explosion, the rhyolite dome volcano lacked magma that supported the structure. The volcano collapsed creating Yellowstone’s Caldera. Basalt lava flows uplift the lithosphere Yellowstone's caldera. To see the plateau rhyolite flows click here.

Cliff Geyser with exposed thermophiles at Black Sand Basin.

Underneath the North American Plate lives Yellowstone's hotspot of deeply rooted magma of extraordinary size and volume. The lithosphere moves southwest while the hotspot remains stationary, creating gigantic calderas in its path. This scar of calderas forms the Snake River Plain, a flood basalt. Follow the link to "Explore volcanic fields" and see the process’ in motion!

 Section cut of Yellowstone's hotspot.(Click to here enlarge)

Intrusive volcanic sills near Tower Falls. (Click image to enlarge)
Evidence shows Yellowstone may erupt again. University of Utah monitors the earthquakes and ground movements, they have about twenty seismic monitoring stations within Yellowstone National Park. Click here for up-to-date earthquake reports. The black lines are representing faults, the green is the swarm of earthquakes from 1995-2009 and the red cluster is the newest swarm in 2010. A total of 2,347 earthquakes shook Yellowstone over a span of four months!
University of Utah Seismic Graph of Yellowstone National Park.
This USGS Geologic Map of Yellowstone demonstrates connections between the fault lines, types of rock, and different areas of lava flows. There is a linear characteristic with the earthquakes and the fault lines along, with laccoliths, in both maps. The Sour Creek Dome and the Mallard Lake Dome are another sign of the volcano emerging once again.


Thursday, January 19, 2012

Introductory Page

Hello fellow readers and bloggers, I am Page Carpenter! Throughout the semester I will be analyzing Yellowstone National Park as a physical geographer. Yellowstone National Park covers more than two million acres! With such a vast terrain I will be focusing on Yellowstone's Caldera as my chosen site.

Morning Glory Pool, Hot Spring in Upper Geyser Basin of Yellowstone

There are two main reasons why I chose Yellowstone: the unique geological and zoological aspect of Yellowstone and it is the first national park in the world. By choosing an icon of treasured landscapes I will research the fine details about Yellowstone's forms and processes to expand the existing knowledge of the park. My family and I explored the wonders of Yellowstone for the first time last summer. With the aid of this blog my next adventure in Yellowstone will be more insightful and enriching!

Yellowstone Caldera is outlined in black dashed lines.
Source: www.nps.gov/yell/

Background image source: http://www.wallcoo.net/nature/2009_Landscape_1680_Desktop_03/wallpapers