The Ubehebe maar volcano.
Photo taken by Dr. R. B. Trombley.
15 February to 17 February 2008
THE TEAM:
Participating in the expedition were INTLVRC's Principal Research Volcanologist, Dr. R. B. Trombley, Senior Technical Assistant, Andy R. Morckel & Special Guest/Observer, Mrs. Karen L. Friedrich.
THE VOLCANO:
At the northern end of the Cottonwood Mountains, lies a field of volcanic craters, the largest of which the Indians named Ubehebe, which means big basket in the rock. Ubehebe was formed around 6000 years ago when underground water came in contact with molten rock. The resultant steam pressure caused a massive explosion, sending debris high into the sky, blanketing the area with jagged rock up to 20ft in depth. There are several craters in the area, the most easily accessed being the largest, Ubehebe. Walking around the rim is very easy though winds are quite often extreme in this part of Death Valley. A simple 500 ft. descent awaits those who feel like walking to the bottom of Ubehebe; a rather more strenuous ascent awaits those who want to climb out, as the slopes are lined with a loose volcanic rubble that offers little purchase.
At the edge of Ubehebe Crater, you'll be greeted by an eerie, surreal landscape. All is quiet now, but you transported to a time just over two thousand years ago. Following weaknesses in Earth's crust, searing basaltic magma rose upward. A fault along the base Tin Mountain, responsible for uplift of the entire mountain range, lay in path of the molten mass, providing an easy escape route to the surface. Magma worked its way through fault-weakened rock where it water-soaked bedrock and alluvial fan sediments. In an instant, water flashed to a sudden, violent release of steam-powered energy blasted away the confining rock above. A dense, ground-hugging cloud of rocky debris surged out from the base at up 100 miles/hour, decimating the landscape.
The largest of these produced Ubehebe Crater, over a mile wide and 752 feet deep. Up to 150 feet of rock debris mantles the countryside near the site of explosion. Over a dozen other explosion craters and tuff rings in the Ubehebe Crater are the result of this type of hydrovolcanic eruption.
THE MISSION:
1. Determine the North American Plate Motion With Respect to Pacific Plate With Reference at The Ubehebe Crater.
2. Crater Rim Magnetometer Readings of the Ubehebe Crater.
3. Determine The Approximate Heat Flow Of The Eruption Of The Little Hebe Crater.
4. Determine the Electrical Conductivity, Resistivity, & pH Signature Of The Ubehebe Crater.
THE WORK:
Research almost never stops on the volcanoes here at the INTLVRC ! This is especially true for our experienced senior staff members like Dr. R. B. Trombley & Dr. Jean-Paul Toutain. who are always trying to make contributions and do training to our colleagues and fellow volcanologists.
Some of the scenes at the Ubehebe maar volcanic site ........
First some of the experiment set-ups --
A few more views around the volcano --
ITS NOT ALL WORK:
THE EXPERIMENT RESULTS:
1. Determine the North American Plate Motion With Respect to Pacific Plate With Reference at The Ubehebe Crater -- Our annual reading of the crater was taken with the GPS unit.The results indicate that the North American Plate is still moving at approximately 44.97mm/yr at a direction of 321.53o .
2. Crater Rim Magnetometer Readings of the Ubehebe Crater -- Eight (8) different points about the volcano's rim were measured with the fluxgate magnetometer where magnetic readings were recorded. The results at this time indicate that average horizontal component was 3,401.13 nT and the vertical component was at an average of 41,525 nT both with relatively small standard deviation. The Magnetic Field Vector averaged 60,028.81 nT, the Total Field Magnitude averaged 41,713.44 nT and the average Inclination of the Field was 85.26o.
3. Determine The Approximate Heat Flow Of The Eruption Of The Little Hebe Crater -- The measurements of the Little Hebe crater were taken on a previous expedition. The data collected therein is used as input for this experiment. The results indicate that the Little Hebe crater had a heat flow above the sediment of 53.47 mWm-2.
4. Determine the Electrical Conductivity, Resistivity, & pH Signature Of The Ubehebe Crater -- Four (4) soil samples were collected from each of the four quadrants of the volcano and processed for pH and Electrical Conductivity measurements. The results show that the average Resistivity of the soild collected were .03 W-m with a s = .01, The average Resistivity, corrected for temperature of the soild collected were .07 W-m with a s = .02, & the average Electrical Conductivity for the soil samples collected was 42.0 mS with s = 9.93.
An excellent set of work and interesting experiments were completed on this expedition.
Upcoming Planned Expeditions for Year 2008 .........
February, 2008 COMPLETED UBEHEBE CRATER, Death Valley, CA, USA (Misc. experiments.)
March, 2008 COMPLETED TAAL, Philippines, (CO2 & Temperature imaging.)
March, 2008 COMPLETED 18th Geological Conference of the Caribbean, Dominican Republic, Caribbean.
April, 2008 COMPLETED COLORADO PLATEAU, Arizona, USA (Tertiary lava sampling.)
April, 2008 COMPLETED SUPERSTITIONS, Canyon Lake area, USA (Level-Transit survey.)
May, 2008 SUNSET CRATER, Arizona, USA (GPS Measurements.)
May, 2008 HUMPHREYS PEAK, Arizona, USA (Plate motion & magnetometer - Part III.)
June, 2008 CAPULIN CRATER, New Mexico, USA (GPS, Magnetometer Measurements.)
June, 2008 MERAPI, Java, Indonesia (Gas sampling & monitoring station set-up.)
September, 2008 Mt. ETNA, Sicily, (Mercury determination, elementary fluxes & isotropic compositions.)
Planned Expeditions for Year 2009 .........
February, 2009 UBEHEBE CRATER, Death Valley, CA, USA (Plate motion, Misc. experiments.)
