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Media Advisory: USGS Tip Sheet for GSA 2005
Released: 10/16/2005 6:39:16 AM

Contact Information:
U.S. Department of the Interior, U.S. Geological Survey
Office of Communication
119 National Center
Reston, VA 20192
Stephanie Hanna 1-click interview
Phone: 206-331-0335

Bill Lukas 1-click interview
Phone: 206-399-7155



 

Sunday, October 16:

Drilling into – and through – the San Andreas Fault: The critical question of whether earthquakes will ever be predictable continues to plague seismologists and the scientific community. To gain a better understanding of earthquake fault mechanics and behavior, a team of scientists is in the process of accumulating needed information about fault behavior at depth through a 2.4 mile deep observatory placed within the San Andreas Fault Zone that will provide researchers with the tools needed to conduct around-the-clock monitoring from inside an active earthquake zone. The San Andreas Fault Observatory at Depth (SAFOD) project is designed to directly measure the physical and chemical conditions under which earthquakes occur along a fault segment near Parkfield, California, an area known for frequent seismic activity. Scientists, through drilling and instrumenting a borehole across the San Andreas Fault Zone, are studying the physics of earthquake generation while determining the makeup and mechanical behavior of an active, plate boundary fault at depth. Drilling through the fault zone, while collecting nearly continuous data and samples, was completed during the summer of 2005. The next phase of SAFOD will permit scientists to compare the minerology, physical properties and deformational behavior of fault rocks that fail primarily through creep against those that fail during earthquakes. (Steve Hickman, Session No. 24, Salt Palace Convention Center: Ballroom B, 8:00 A.M - 8:15 A.M)

How do lasers, tree rings and mining relate? Land, water and biota commonly show elevated concentrations of toxic metals in areas that are mineralized. Mining activity may raise these values further. This presents two major issues that have important consequences for the methods and costs of environmental remediation. First, determining the natural background, in other words, how much remediation is required. Second, determining the effect of human activities. The USGS evaluated the use of the chemistry of individual tree rings using a laser in an abandoned mining district in Colorado to address these problems. The tree rings act as a surrogate clock and scientists discovered that there are distinct increases in several metals that correspond to the period of active mining. Thus, this approach may provide a highly effective tool in remediation activities. USGS scientist W. Ian Ridley will present the findings on Oct. 16 at 2:35 p.m., Room 254B.

A New Look at an Old Continent: The grand geologic architecture of North America is depicted on a new geologic map recently published by GSA. The previous geologic map of North America was published in 1965, prior to wide acceptance of plate tectonics, development of modern methods of rock dating, and significant data on the geology of the sea floors was available. Various aspects of the recently released Geologic Map of North America will be displayed at a series of poster sessions on Oct. 16 by the three compilers, John C. Reed of the USGS, John O. Wheeler of the Geological Survey of Canada, and Brian E. Tucholke of the Woods Hole Oceanographic Institution. The map is primarily a "thinking document." It will be a valuable teaching aid, as well as a guide in developing new strategies in the search for mineral and energy resources, and in formulating research programs in such diverse fields as prediction of earthquakes and volcanic eruptions, delineation and understanding of natural ecosystems, assessing ground water aquifers, and evaluating the effects of geology on human health. The sessions will be on display at the Salt Palace Convention Center, Hall C from 8 a.m. to 12 p.m.

Monday, October 17:

Tapping Texas water sources via geology: In the last decade, earth scientists from the USGS have combined forces with academia and other federal, state, and local agencies to reveal the geologic architectures of two important aquifer systems in central Texas: (1) the Edwards aquifer that lies between the Balcones fault zone south of Austin to south and west of San Antonio, and (2) the Trinity aquifer located in the Texas Hill Country west and south of Austin and in the deeper parts of the Balcones fault zone. The results of a 5-year USGS study of the Edwards and Trinity aquifers will be highlighted during Surface and Subsurface Geological Characterization of the Edwards and Trinity Carbonate Aquifer Systems, central Texas, from 8 to 11 a.m. on Oct. 17 in Room The diverse geologic disciplines reflected in this session include presentations on bedrock, and structural geologic mapping, hydrologic and three-dimensional (3-D) modeling, ground and airborne geophysical surveys, and isotopic geology including noble gas and tracer studies.

California going dry? Ground-water is an important source of water in many areas and the availability of ground water is becoming critical as population growth and development increase. Poor ground water quality can reduce the availability of ground water by decreasing the volume of water suitable for human use. In a case study of the Central Valley Aquifer in California, water quality results suggest that a substantial volume of ground water may be unavailable for human use. This is because the levels of some contaminants are of potential human health concern in many of the sampled wells. However, the levels of these contaminants may not be representative of the entire aquifer and can be reduced by treatment. USGS scientist Michael Moran will share his research during a session on Groundwater Quality and Quantity Interconnections, on Monday, Oct. 17 at 2:55 p.m. in Room 250C.

Alaskan quake triggers telling landslides: In November of 2002 a major earthquake, magnitude 7.9, struck central Alaska, making it the largest temblor of the year. The earthquake occurred in a remote wilderness containing very few seismographs, and so a valuable opportunity to record a large earthquake was missed. Damage was light in this sparsely populated area, but the earthquake did trigger several huge landslides, some of which traveled as far as 7 miles at speeds estimated at more than 125 miles per hour. Geologists analyzing these and other landslides were able to estimate several characteristics of the earthquake ground shaking even in the absence of modern instruments. Landslide observations suggest that this earthquake generated lower ground shaking than would have been expected considering the large magnitude. The ground shaking also appears to have died off rapidly away from the fault zone rather than severely shaking a broad region. These observations are confirmed by studies of recordings of the earthquake made at greater distances. Many seismically active parts of the world lack adequate seismic instrumentation, and analysis of triggered landslides provides a valuable tool to estimate some of the characteristics of earthquake shaking in such areas. USGS scientist Randy Jibson will present his research during a session on Seismogenic Landslides on Oct. 17 at 4:10 p.m. in Room 254B.

Mapping ground-water recharge in Navajo Sandstone, Washington County, Utah: Direct infiltration of precipitation to permeable bedrock aquifers, often the most important form of ground-water recharge, has been particularly difficult to quantify at the regional scale in arid climates. To assist with this problem, GIS techniques for regional estimates of recharge to desert sandstone are currently being developed. These GIS methods are based on infiltration rates determined by using environmental tracers from both boreholes and basin-scale trenches. Tracer studies show that infiltration is extremely variable and highest beneath course-grained soils and areas receiving run-on from exposed outcrops during rain events. Soil coarseness, soil thickness, topographic slope, distance to upgradient outcrop, and sandstone fracture density were identified as potential controlling parameters. Because these surficial data are available from geologic, soils, and topographic maps, regional-scale recharge maps can be readily constructed. These techniques were used to create a recharge map of the Navajo Sandstone Aquifer in Washington County, Utah, for water-resources evaluation, recharge area source-protection, and land-use planning and zoning purposes. (Victor Heilweil 9:00 AM-9:15 AM Salt Palace Convention Center: 250 C)

"Smoggy" Titan’s surface as viewed from the Huygens probe: The Descent Imager/Spectral Radiometer (DSIR) aboard the Huygens Probe has successfully characterized the atmospheric radiation, and returned images and spectra of Titan’s surface. Measurements of near-surface methane concentrations reveal that methane fog or rain conditions at the surface landing site are unlikely at the present time. Perceived atmospheric wind conditions are indicative of a boundary layer being present with zonal wind directions shifting from east to west below about 8 km. Observed surface reflectance data is consistent with that of dirty water ice. DSIR images show brighter, higher terrains with stubby and higher-order drainage systems that border darker, lower-lying plains scoured by flowing liquid; surface images show rounded cobbles in a dry river bed. DSIR-derived topography for drainages in the bright terrain show extremely rugged terrain with slopes as much as 30?, suggesting relatively rapid erosion by flowing liquid (likely liquid and methane) in the river beds resulting in the deeply incised valleys. (Laurence Soderblom 4:10 PM-4:30 PM, Salt Palace Convention Center: Ballrooms AC)

Tuesday, October 18:

Watershed transportation of mercury from historical gold mining in northern California: Clear Creek, a tributary of the Sacramento River drains most of the mineralized area of the French Gulch Mining District, the most productive lode gold district in the Klamath Mountains region of California. Downstream from the French Gulch district, late Tertiary and Quaternary alluvial deposits have been mined for gold by various placer methods including hydraulic mining and dredging, resulting in mercury contamination of sediments. In addition, mercury-contaminated lode-mine tailings released from the French Gulch district are also incorporated in the active stream sediments. Mercury concentrations in waters of lower Clear Creek have been investigated under various flow conditions, and in other environments including floodplain ponds, impoundments in dredge tailings, wetlands ponds constructed in tailings, and drainage from gravel wash ponds from dredge tailings. Under all seasonal conditions in these environments a significant proportion of the mercury present is associated with particle sizes capable of transporting mercury during high flow stream conditions. (Roger Ashley, Salt Palace Convention Center: 250 DE, 8:25 AM-8:40 AM)

Smoothing Contentious Bay-Delta Waters – CALFED Program Provides Link between Water Science Issues and Policymakers: During recent history, communication between environmental scientists and policymakers has often been characterized by advocacy, or unclear goals. The CALFED Bay-Delta program is a controversial multi-stakeholder attempt to redesign how 60% of California’s water is managed, and to restore ecosystems over 40% of the state. Scientific goals of the project include explaining and reducing the uncertainties that challenge restoration and water management; and developing improved collaboration between government agencies, universities, and stakeholders. The CALFED approach to facilitating communication of science needs utilized forums and program reviews that directly incorporated contributions from different disciplines directed at a particular issue, and used agendas designed to minimize advocacy debates. The role of science in these programs was an ongoing, policy-neutral dialogue that continually updated advancing knowledge of the Bay-Delta system. Development of new scientific understanding, in concert with an active and effective communication strategy, influenced decisions on species listings that resulted in unanticipated schemes for managing water and assisted in reducing support for unworkable proposals. Although scientific contributions were rarely cited as the cause of change, the overall effort retained a credibility that reflected the essential contribution of scientific integrity. (Samuel Luoma, Session No. 172, Salt Palace Convention Center: Ballrooms AC, 3:15 PM-3:35 PM)

Wednesday, October 19:

THE 2004-2005 ERUPTION OF MOUNT ST. HELENS

New Insights and Hazard Management of an Extraordinary Dacitic Dome-Growth Eruption

Aerial photographic monitoring of lava dome growth rate: In October 2004, a new period of dome growth began that dramatically changed the topography of the Mount St. Helens crater. Large quantities of lava were extruded onto the crater floor immediately south of the 1980-1986 lava dome, intensely deforming and cutting a new glacier in two, resulting in spectacular crevassing and rapid advance of the eastern glacial arm. Vertical and oblique aerial photography of morphologic changes allowed construction of highly accurate detailed digital elevation models. The models were used to quantify volumetric changes associated with dome emplacement, growth, and collapse, as well as for studying the deformation of glacial ice and enabling improved quantitative geologic analysis. (Steve Schilling, Poster Sessions: Salt Palace Convention Center: Ballrooms AC, 1:45 PM-2:05 PM)

Ground-based images documenting lava dome growth: In October, 2004, USGS scientists deployed a digital still camera near the mouth of Mount St. Helens crater to automatically document and transmit pictures, indirectly by satellite, to the Cascades Volcano Observatory. These images help scientists assess eruptive behavior, growth of a lava dome, and conditions inside the crater. Through a series of photogrammetric calculations, utilizing aerial photography, scientists are able to calculate both lateral and vertical dome growth and learn more about lava dome configuration without exposure to hazardous conditions within the crater. (Jon Major, Poster Sessions: Salt Palace Convention Center: Ballrooms AC, 2:25 PM-2:45 PM)

Composition of the crater lava dome: Fresh dacite lava samples helicopter-dredged from the 2004-2005 Mount St. Helens lava dome are at the silica-rich end of the silicon dioxide-time trend compared to dome lavas from the 1980-1986 eruptive period, and are characterized by matrices having a low abundance of glass and vesicles. Information from physical and chemical rock properties taken together with field data indicate first slow cooling, degassing, and internal crystal growth in the magma at depths exceeding about 5 km, probably within the remains of the 1980 lava reservoir, followed by a transient heating event and ascent to levels below the base of the 1992-2004 shallow earthquake zone at a depth of about 3 km, then by final degassing and extensive crystallization during ascent to shallow levels below the vent -- a multistage history that led to an extremely viscous, gas-poor, and crystal-rich extrusion, and which has been accompanied by only limited explosive activity. (John Pallister, Poster Sessions: Salt Palace Convention Center: Ballrooms AC, 3:05 PM-3:25 PM)

Questioning Quaternary Faults in Afghanistan: There is no doubt that quaternary faults exist since Afghanistan is situated in one of the most earthquake-prone regions of the world, but a new effort may shed additional light on AfghanistanÌs risk. In conjunction with USAID, the USGS is helping to build an active fault map and database of Afghanistan for future development and earthquake hazard reduction. Earthquake hazard reduction and awareness are pivotal for the restoration and advancement of Afghanistan. This project will use satellite imagery for remote sensing of active earthquake source zones and will train Afghan geologists to perform more detailed, site-specific earthquake fault investigations. The active fault map and database will provide a template that Afghanistan and other geologists can refine and improve as more detailed fieldwork is performed. By delineating and characterizing earthquake source zones, Afghanistan infrastructural development can proceed with awareness of the hazardous regions. This kind of data will support the creation of a national seismic hazard map, as well as inform engineers of the inherent seismic hazard when designing new structures and retro-fitting older less competent structures. (C.A. Ruleman, 1:30 PM-5:30 PM, Salt Palace Convention Center: Hall C, Session No. 256--Booth# 1)

Yosemite National Park Rock-Falls: Rock Falls, rock slides, and other forms of slope failures are a serious natural hazard in Yosemite National Park. Following the 1980 Mammoth Lakes earthquakes, which triggered rockfalls and rock slides in Yosemite Valley, the USGS began to examine reports of historic and recent events with the National Park Service (NPS). The effort has resulted in rock-fall inventories providing information on the number, size, frequency, and recognized triggers of rock falls within Yosemite National Park. As many as 540 reported slope failures have been documented between 1857 and 2004, resulting in 14 deaths and at least 62 injuries. Falling rock in Yosemite Valley continues to pose a serious geologic risk because of high potential for continuing failure from steep cliffs, the location of some facilities near the base of cliffs, and the nearly 4 million annual visitors to the park. Since 1980, there have been an average of about 10 documented slope failures per year. The rock-fall inventory provides a basis for assessing potential slope failures within the Valley, providing scientists and NPS managers with needed information to restrict future development in rock-fall talus areas, and to identify and monitor areas that could be potentially dangerous to the public. (Gerald Wieczorek Session No. 221, Palace Convention Center: 251 E 8:15 AM-8:30 AM)

What’s being done in Sumatra to improve tsunami detection? The USGS has assessed earthquake shaking hazards in Sumatra and southeast Asia for the past 20 years. Most recently, USGS scientists published a hazard map for Sumatra showing significant impacts from the great M 9.2 earthquake and subsequent tsunami that occurred in December 2004. Due to this quake, the shaking hazard has increased along the 1900-km long Sumatra fault that transects the entire island and typically creates large earthquakes. Shaking along these megathrust segments and inland faults will cause significant damage to populations across the island. The USGS is collaborating with NOAA on a project funded by USAID to improve delivery of seismic and tide information, to improve detection and warning of large earthquakes and tsunamis, to strengthen capacity of emergency response, and to map potential earthquake hazards and tsunami inundation regions across portions of southeast Asia that were affected by the 2004 tsunami. USGS scientist Mark Petersen will provide additional insight on this work during Session 247, This Changing Planet: Explaining Geologic Hazards to the Media, Policy Makers, and the General Public, on Oct. 19 at 4:45 p.m. in Room 254B.


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