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  1. Helen Keller: A Remembrance.

    ERIC Educational Resources Information Center

    Lowenfeld, Berthold

    1980-01-01

    A well-known educator and author in the field of work with the blind recalls times he spent with Helen Keller, including her visit to the California School for the Blind, where he was superintendent, for the consecration of the Helen Keller Building. (Author/SBH)

  2. Mt. St. Helens Memories.

    ERIC Educational Resources Information Center

    Sharp, Len

    1992-01-01

    Provides a personal account of one science teacher's participation in a teacher workshop in which teachers learned about volcanic development, types of eruption, geomorphology, plate tectonics, volcano monitoring, and hazards created by volcanoes by examining Mt. St. Helens. Provides a graphic identifying volcanoes active since 1975. (MDH)

  3. The Helen of Geometry

    ERIC Educational Resources Information Center

    Martin, John

    2010-01-01

    The cycloid has been called the Helen of Geometry, not only because of its beautiful properties but also because of the quarrels it provoked between famous mathematicians of the 17th century. This article surveys the history of the cycloid and its importance in the development of the calculus.

  4. Who's Helen Keller?

    ERIC Educational Resources Information Center

    Hubbard, Ruth Shagoury

    2003-01-01

    Helen Keller was someone who worked throughout her long life to achieve social change; she was an integral part of many important social movements in the 20th century. Her life story could serve as a fascinating example for children, but most picture books about Keller are silent about her life's work. In this article, the author examines the…

  5. Replanting St. Helens

    SciTech Connect

    Holbrook, J.J.

    1986-05-01

    On May 18, 1980 an earthquake beneath the north side of Mt. St. Helens triggered the eruption of this volcano. This eruption caused damage to 160,000 acres of forests, meadows, lakes and streams. This paper discussed the reforestation of approximately 50,000 acres of devastated land which was located around the site of the eruption. It also discussed the natural recovery of this area and the reestablishment of ecosystems and rebuilding of habitats by the plants and animals.

  6. Mount St. Helens Flyover

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) image of Mt. St. Helens volcano in Washington State was acquired on August 8, 2000 and covers an area of 37 by 51 km. Mount Saint Helens, a volcano in the Cascade Range of southwestern Washington that had been dormant since 1857, began to show signs of renewed activity in early 1980. On 18 May 1980, it erupted with such violence that the top of the mountain was blown off, spewing a cloud of ash and gases that rose to an altitude of 19 kilometers. The blast killed about 60 people and destroyed all life in an area of some 180 square kilometers (some 70 square miles), while a much larger area was covered with ash and debris. It continues to spit forth ash and steam intermittently. As a result of the eruption, the mountain's elevation decreased from 2,950 meters to 2,549 meters. The simulated fly-over was produced by draping ASTER visible and near infrared image data over a digital topography model, created from ASTER's 3-D stereo bands. The color was computer enhanced to create a 'natural' color image, where the vegetation appears green. The topography has been exaggerated 2 times to enhance the appearance of the relief. Landsat7 aquired an image of Mt. St. Helens on August 22, 1999. Image and animation courtesy NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team.

  7. Mount St. Helens Rebirth

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The catastrophic eruption of Mt. St. Helens 20 years ago today (on May 18, 1980), ranks among the most important natural events of the twentieth century in the United States. Because Mt. St. Helens is in a remote area of the Cascades Mountains, only a few people were killed by the eruption, but property damage and destruction totaled in the billions of dollars. Mount St. Helens is an example of a composite or stratovolcano. These are explosive volcanoes that are generally steep-sided, symmetrical cones built up by the accumulation of debris from previous eruptions and consist of alternating layers of lava flows, volcanic ash and cinder. Some of the most photographed mountains in the world are stratovolcanoes, including Mount Fuji in Japan, Mount Cotopaxi in Ecuador, Mount Hood in Oregon, and Mount Rainier in Washington. The recently erupting Mount Usu on the island of Hokkaido in Japan is also a stratovolcano. Stratovolcanoes are characterized by having plumbing systems that move magma from a chamber deep within the Earth's crust to vents at the surface. The height of Mt. St. Helens was reduced from about 2950 m (9677 ft) to about 2550 m (8364 ft) as a result of the explosive eruption on the morning of May 18. The eruption sent a column of dust and ash upwards more than 25 km into the atmosphere, and shock waves from the blast knocked down almost every tree within 10 km of the central crater. Massive avalanches and mudflows, generated by the near-instantaneous melting of deep snowpacks on the flanks of the mountain, devastated an area more than 20 km to the north and east of the former summit, and rivers choked with all sorts of debris were flooded more than 100 km away. The area of almost total destruction was about 600 sq. km. Ash from the eruption cloud was rapidly blown to the northeast and east producing lightning which started many small forest fires. An erie darkness caused by the cloud enveloped the landscape more than 200 km from the blast area, and ash

  8. Mt. St. Helens

    NASA Technical Reports Server (NTRS)

    2001-01-01

    [figure removed for brevity, see original site] [figure removed for brevity, see original site] Figure 1 Movie

    This 3-D anaglyph image of Mt. St. Helens volcano combines the nadir-looking and back-looking band 3 images of ASTER. To view the image in stereo, you will need blue-red glasses. Make sure to look through the red lens with your left eye. Figure 1: This ASTER image of Mt. St. Helens volcano in Washington was acquired on August 8, 2000 and covers an area of 37 by 51 km. Mount Saint Helens, a volcano in the Cascade Range of southwestern Washington that had been dormant since 1857, began to show signs of renewed activity in early 1980. On 18 May 1980, it erupted with such violence that the top of the mountain was blown off, spewing a cloud of ash and gases that rose to an altitude of 19 kilometers. The blast killed about 60 people and destroyed all life in an area of some 180 square kilometers (some 70 square miles), while a much larger area was covered with ash and debris. It continues to spit forth ash and steam intermittently. As a result of the eruption, the mountain's elevation decreased from 2,950 meters to 2,549 meters. The image is centered at 46.2 degrees north latitude, 122.2 degrees west longitude.

    Movie: The simulated fly-over was produced by draping ASTER visible and near infrared image data over a digital topography model, created from ASTER's 3-D stereo bands. The color was computer enhanced to create a natural color image, where the vegetation appears green. The topography has been exaggerated 2 times to enhance the appearance of the relief.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  9. Rebuilding Mount St. Helens

    USGS Publications Warehouse

    Schilling, Steve P.; Ramsey, David W.; Messerich, James A.; Thompson, Ren A.

    2006-01-01

    On May 18, 1980, Mount St. Helens, Washington exploded in a spectacular and devastating eruption that shocked the world. The eruption, one of the most powerful in the history of the United States, removed 2.7 cubic kilometers of rock from the volcano's edifice, the bulk of which had been constructed by nearly 4,000 years of lava-dome-building eruptions. In seconds, the mountain's summit elevation was lowered from 2,950 meters to 2,549 meters, leaving a north-facing, horseshoe-shaped crater over 2 kilometers wide. Following the 1980 eruption, Mount St. Helens remained active. A large lava dome began episodically extruding in the center of the volcano's empty crater. This dome-building eruption lasted until 1986 and added about 80 million cubic meters of rock to the volcano. During the two decades following the May 18, 1980 eruption, Crater Glacier formed tongues of ice around the east and west sides of the lava dome in the deeply shaded niche between the lava dome and the south crater wall. Long the most active volcano in the Cascade Range with a complex 300,000-year history, Mount St. Helens erupted again in the fall of 2004 as a new period of dome building began within the 1980 crater. Between October 2004 and February 2006, about 80 million cubic meters of dacite lava erupted immediately south of the 1980-86 lava dome. The erupting lava separated the glacier into two parts, first squeezing the east arm of the glacier against the east crater wall and then causing equally spectacular crevassing and broad uplift of the glacier's west arm. Vertical aerial photographs document dome growth and glacier deformation. These photographs enabled photogrammetric construction of a series of high-resolution digital elevation models (DEMs) showing changes from October 4, 2004 to February 9, 2006. From the DEMs, Geographic Information Systems (GIS) applications were used to estimate extruded volumes and growth rates of the new lava dome. The DEMs were also used to quantify dome

  10. Mount St. Helens

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) image of Mount St. Helens was captured one week after the March 8, 2005, ash and steam eruption, the latest activity since the volcano's reawakening in September 2004. The new lava dome in the southeast part of the crater is clearly visible, highlighted by red areas where ASTER's infrared channels detected hot spots from incandescent lava. The new lava dome is 155 meters (500 feet) higher than the old lava dome, and still growing.

    With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet.

    ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products.

    The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

    Size: 21.9 by 24.4 kilometers (13.6 by 15.1 miles) Location: 46.2 degrees North latitude, 122.2 degrees West longitude Orientation: North at top Image Data: ASTER bands 8, 3, and 1 Original Data Resolution

  11. Helene: A Plastic Model

    NASA Astrophysics Data System (ADS)

    Umurhan, O. M.; Moore, J. M.; Howard, A. D.; Schenk, P.; White, O. L.

    2014-12-01

    Helene, the Saturnian L4 Trojan satellite co-orbiting Dionne and sitting within the E-ring, possesses an unusual morphology characteristic of broad km-scale basins and depressions and a generally smooth surface patterned with streaks and grooves which are indicative of non-typical mass transport. Elevation angles do not appear to exceed 10o at most. The nature and origin of the surface materials forming these grooved patterns is unknown. Given the low surface gravity (<5mm/s2), it hard to imagine how such transport features can come about with such low grades and surface gravities. Preliminary examinations of classical linear and nonlinear mass wasting mechanisms do not appear to reproduce these curious features. A suite of hypothesis that we examine is the possibility that the fine grain material on the surface has been either (i) accreted or (ii) generated as refractory detritus resulting from sublimation of the icy bedrock, and that these materials subsequently mass-waste like a non-Newtonian highly non-linear creeping flow. Modifying the landform evolution model MARSSIM to handle two new mass-wasting mechanism, the first due to glacial-like flow via Glen's Law and the second due to plastic-like flow like a Bingham fluid, we setup and test a number of likely scenarios to explain the observations. The numerical results qualitatively indicate that treating the mass-wasting materials as a Bingham material reproduces many of the qualitative features observed. We also find that in those simulations in which accretion is concomitant with Bingham mass-wasting, the long time-evolution of the surface flow shows intermittency in the total surface activity (defined as total surface integral of the absolute magnitude of the mass-flux). Detailed analyses identify the locations where this activity is most pronounced and we will discuss these and its implications in further detail.

  12. Mount Saint Helens aerosol evolution

    NASA Technical Reports Server (NTRS)

    Oberbeck, V. R.; Farlow, N. H.; Snetsinger, K. G.; Ferry, G. V.; Fong, W.; Hayes, D. M.

    1982-01-01

    Stratospheric aerosol samples were collected using a wire impactor during the year following the eruption of Mt. St. Helens. Analysis of samples shows that aerosol volume increased for 6 months due to gas-to-particle conversion and then decreased to background levels in the following 6 months.

  13. Mt. St. Helens and Spirit Lake

    NASA Technical Reports Server (NTRS)

    2002-01-01

    high resolution 1000 pixel-wide image Snow still covered the peaks of the Cascade Ranges in mid-June when the STS-111 crew photographed Mt. St. Helens from the Space Shuttle Endeavour. From their vantage point, the crew observed blast zone from the 1980 eruption of the volcano, the mud-choked North Fork of the Toutle River, and fallen timber that still floats in rafts of logs on Spirit Lake. Continued imagery of the region will document the slow regrowth of the forests. Today, the volcano and surrounding region comprise the Mt. St. Helens National Volcanic Monument which is dedicated to research, education and recreation. For more information visit: Mount St. Helens National Volcanic Monument. Astronaut photograph STS111-371-3 was provided by the Earth Sciences and Image Analysis Laboratory at Johnson Space Center. Additional images taken by astronauts and cosmonauts can be viewed at the NASA-JSC Gateway to Astronaut Photography of Earth.

  14. Open letter to Minister Helen Morton.

    PubMed

    Campbell, Emma; Oke, Lin; Cairney, Joanne; Fergusson, Fiona; Booth, Jodie; Taylor, Karen; Baird, Tyson; Sheppard, Loretta; Jensen, Heather; Kao, Kevin

    2015-10-01

    This letter was sent to the Honourable Helen Morton by Emma Campbell after the Occupational Therapy Australia National Conference. A number of members of First Australian and Australian OTs online were keen to show their support for Emma's letter and share this with other OT colleagues. PMID:26726327

  15. Mount St. Helens Classroom Activities: Elementary.

    ERIC Educational Resources Information Center

    Washington State Educational Service District 112, Vancouver.

    This teacher's guide is designed to provide elementary teachers with an assortment of classroom activities dealing with the Mt. St. Helens eruption of May 18, 1980, in the areas of science, social studies, math, language arts, and school newspaper activities. Copy masters and teacher versions of all activities are contained with this guide,…

  16. Mount St. Helens Classroom Activities: Secondary.

    ERIC Educational Resources Information Center

    Washington State Educational Service District 112, Vancouver.

    This teacher's guide is designed to provide secondary teachers with an assortment of classroom activities dealing with the Mt. St. Helens eruption of May 18, 1980, in the areas of science, social studies, math, language arts and school newspaper activities. Copy masters and teacher versions of all activities are contained within this guide,…

  17. Mount St. Helens and Kilauea volcanoes

    SciTech Connect

    Barrat, J. )

    1989-01-01

    Mount St. Helens' eruption has taught geologists invaluable lessons about how volcanoes work. Such information will be crucial in saving lives and property when other dormant volcanoes in the northwestern United States--and around the world--reawaken, as geologists predict they someday will. Since 1912, scientists at the U.S. Geological Survey's Hawaiian Volcano Observatory have pioneered the study of volcanoes through work on Mauna Loa and Kilauea volcanoes on the island of Hawaii. In Vancouver, Wash., scientists at the Survey's Cascades Volcano Observatory are studying the after-effects of Mount St. Helens' catalysmic eruption as well as monitoring a number of other now-dormant volcanoes in the western United States. This paper briefly reviews the similarities and differences between the Hawaiian and Washington volcanoes and what these volcanoes are teaching the volcanologists.

  18. Mount St. Helens and Kilauea volcanoes

    USGS Publications Warehouse

    Barrat, J.

    1989-01-01

    From the south, snow-covered Mount St. Helens looms proudly under a fleecy halo of clouds, rivaling the majestic beauty of neighboring Mount Rainer, Mount Hood, and Mount Adams. Salmon fishermen dot the shores of lakes and streams in the mountain's shadow, trucks loaded with fresh-cut timber barrel down backroads, and deer peer out from stands of tall fir trees. 

  19. 30 Cool Facts about Mount St. Helens

    USGS Publications Warehouse

    Driedger, Carolyn; Liz, Westby; Faust, Lisa; Frenzen, Peter; Bennett, Jeanne; Clynne, Michael

    2010-01-01

    Commemorating the 30th anniversary of the 1980 eruptions of Mount St. Helens 1-During the past 4,000 years, Mount St. Helens has erupted more frequently than any other volcano in the Cascade Range. 2-Most of Mount St. Helens is younger than 3,000 years old (younger than the pyramids of Egypt). 3-Some Native American names that refer to smoke at the volcano include- Lawala Clough, Low-We- Lat-Klah, Low-We-Not- Thlat, Loowit, Loo-wit, Loo-wit Lat-kla, and Louwala-Clough. 4-3,600 years ago-Native Americans abandoned hunting grounds devastated by an enormous eruption four times larger than the May 18, 1980 eruption. 5-1792-Captain George Vancouver named the volcano for Britain's ambassador to Spain, Alleyne Fitzherbert, also known as Baron St. Helens. 6-1975-U.S. Geological Survey geologists forecasted that Mount St. Helens would erupt again, 'possibly before the end of the century.' 7-March 20, 1980-A magnitude 4.2 earthquake signaled the reawakening of the volcano after 123 years. 8-Spring 1980-Rising magma pushed the volcano's north flank outward 5 feet per day. 9-Morning of May 18, 1980- The largest terrestrial landslide in recorded history reduced the summit by 1,300 feet and triggered a lateral blast. 10-Within 3 minutes, the lateral blast, traveling at more than 300 miles per hour, blew down and scorched 230 square miles of forest. 11-Within 15 minutes, a vertical plume of volcanic ash rose over 80,000 feet. 12-Afternoon of May 18, 1980-The dense ash cloud turned daylight into darkness in eastern Washington, causing streetlights to turn on in Yakima and Ritzville. 13-The volcanic ash cloud drifted east across the United States in 3 days and encircled Earth in 15 days. 14-Lahars (volcanic mudflows) filled rivers with rocks, sand, and mud, damaging 27 bridges and 200 homes and forcing 31 ships to remain in ports upstream. 15-The May 18, 1980 eruption was the most economically destructive volcanic event in U.S. history. 16-Small plants and trees beneath winter snow

  20. Crossing the Divide: Helen Keller and Yvonne Pitrois Dialogue on Diversity

    ERIC Educational Resources Information Center

    Hartig, Rachel

    2007-01-01

    How do those who are living with a difference most effectively cross the cultural divide and explain themselves to mainstream society? This is a central question raised by Yvonne Pitrois in her biography of Helen Keller, titled "Une nuit rayonnante: Helen Keller" [A Shining Night: Helen Keller]. Helen Keller responded to Pitrois' book in a…

  1. HELEN Sawyer HOGG (1905-1993)

    NASA Astrophysics Data System (ADS)

    Pipher, Judith L.

    1993-12-01

    With Helen Sawyer Hogg's death in January 1993, the astronomical community lost a most distinguished scientist as well as a visionary role model for female astronomers, and Canada lost a gifted educator of both students and the public. For over 60 years she was a leading authority on variable stars in globular clusters, publishing in excess of 200 papers; an International Astronomical Union Colloquium was held in honor of her life work in August 1972. Her contributions were recognized by many national and international awards throughout her career, including Fellow of the Royal Society of Canada in 1946 (first woman in Physical Sciences) and Companion of the Order of Canada in 1976.

  2. Obituary: Helen Dodson Prince, 1905-2002

    NASA Astrophysics Data System (ADS)

    Lindner, Rudi Paul

    2009-01-01

    Helen Dodson Prince, a pioneer in the observation of solar flares, a pioneer in women's rise in the profession of astronomy, and a respected and revered educator of future astronomers, died on 4 February 2002 in Arlington, Virginia. Helen Dodson was born in Baltimore, Maryland, on 31 December 1905. Her parents were Helen Walter and Henry Clay Dodson. Helen went to Goucher College in nearby Towson with a full scholarship in mathematics. She turned to astronomy under the influence of a legendary teacher, Professor Florence P. Lewis, and she graduated in 1927. Funded by grants and private charity, she earned the Ph.D. in astronomy at the University of Michigan under the direction of Heber Doust Curtis in 1933. Dodson taught at Wellesley College from 1933 until 1943, when she went on leave to spend the last three years of World War II at the MIT Radiation Laboratory. She returned to Goucher after the war as professor of astronomy and mathematics, and in 1947 she came back to Michigan both as professor of astronomy and staff member of the McMath-Hulbert Observatory, of which she became associate director. In 1976 she retired from Michigan and spent her later years in Alexandria, Virginia. In 1932 Dodson held the Dean Van Meter fellowship from Goucher; in 1954 she received the Annie Jump Cannon Prize from the AAS; and in 1974 The University of Michigan honored her with its Faculty Distinguished Achievement Award. She published over 130 articles, mostly on her research specialty, solar flares. Dodson's interest in the Sun began at Michigan, although her dissertation was, like so many Michigan dissertations of the era, on stellar spectroscopy, "A Study of the Spectrum of 25 Orionis." She came to Michigan during the establishment and growth of the solar observatory at Lake Angelus, the creation of three gifted and industrious amateurs. Heber Curtis fostered the growth of the McMath-Hulbert enterprise and brought it into the University. Dodson's solar activity grew as a

  3. Helen Keller Centers for Deaf-Blind Youth and Adults.

    ERIC Educational Resources Information Center

    American Annals of the Deaf, 2003

    2003-01-01

    This listing provides directory information for the national Helen Keller Center and its 10 regional offices. The centers provide extensive evaluative and rehabilitation services to people who are deaf and blind. (CR)

  4. A visit to Mount St. Helens

    SciTech Connect

    Meadows, D.G.

    1994-04-01

    The May 18, 1980, eruption displaced roughly 2.6 km[sup 3] of rock and devastated more than 500 km[sup 2] of forest, mostly to the north of the mountain. Trees within 10--15 km of the mountain peak were burned and uprooted. Beyond that, high winds and flying debris created a blowdown zone. Up to 150 m of rock and ice covered some areas. Accumulations of ash were measured as much as 330 km from the volcano. Mud flows choked nearby rivers and streams. Two years later, the US Congress established the 44,000-hectare Mount St. Helens National Volcanic Monument. The Act essentially directed the USDA Forest Service to allow the area to recover naturally. The paper reviews what changes the ecosystem has been going through since the eruption and the lessons learned that suggest some new resource management techniques.

  5. Helen (Lena) Stavridou Astin (1932-2015).

    PubMed

    Harway, Michele

    2016-09-01

    This article memorializes Helen (Lena) Stavridou Astin, who died at her home October 27, 2015 after a long illness. As only the second woman to earn a doctorate in psychology at the University of Maryland, Lena opened the door for other women. Her 1969 classic book, , was the first to provide data to counteract the belief that highly educated women drop out of the labor force to concentrate on family. Within the American Psychological Association, Lena was the first chair of what became the Committee on Women in Psychology and the second president of the Division on the Psychology of Women (Division 35). She also served on several American Psychological Association governance boards. During her early years, she worked at the National Academy of Science, the Bureau of Social Science Research, and University Research Associates. (PsycINFO Database Record

  6. Helen (Lena) Stavridou Astin (1932-2015).

    PubMed

    Harway, Michele

    2016-09-01

    This article memorializes Helen (Lena) Stavridou Astin, who died at her home October 27, 2015 after a long illness. As only the second woman to earn a doctorate in psychology at the University of Maryland, Lena opened the door for other women. Her 1969 classic book, , was the first to provide data to counteract the belief that highly educated women drop out of the labor force to concentrate on family. Within the American Psychological Association, Lena was the first chair of what became the Committee on Women in Psychology and the second president of the Division on the Psychology of Women (Division 35). She also served on several American Psychological Association governance boards. During her early years, she worked at the National Academy of Science, the Bureau of Social Science Research, and University Research Associates. (PsycINFO Database Record PMID:27571532

  7. An upgraded theory for Helene, Telesto, and Calypso

    NASA Astrophysics Data System (ADS)

    Oberti, P.; Vienne, A.

    2003-01-01

    A tridimensional model including the perturbation due to Saturn's oblateness provides accurate solutions for the motions of Tethys and Dione's Lagrangian satellites Telesto, Calypso, and Helene. Expanded around the Lagrangian points and compared to numerical simulations to check their reliabilities, the solutions are fitted to almost twenty years of data thanks to recently published observations. User-friendly compact series give Telesto, Calypso, and Helene's positions and velocities in the mean ecliptic and equinox of J2000.

  8. Mineral dust transport toward Hurricane Helene (2006)

    NASA Astrophysics Data System (ADS)

    Schwendike, Juliane; Jones, Sarah C.; Vogel, Bernhard; Vogel, Heike

    2016-05-01

    This study investigates the transport of mineral dust from its source regions in West Africa toward the developing tropical cyclone Helene (2006) and diagnoses the resulting properties of the air influencing the tropical cyclonegenesis. The model system COSMO-ART (Consortium for Small-Scale Modelling-Aerosols and Reactive Trace gases) in which the emission and transport of mineral dust as well as the radiation feedback are taken into account, was used. The emission of mineral dust between 9 and 14 September 2006 occurred in association with the relatively strong monsoon flow and northeasterly trade winds, with gust fronts of convective systems over land, and with the Atlantic inflow. Additionally, increased surface wind speed was linked to orographical effects at the Algerian Mountains, Atlas Mountains, and the Hoggar. The dust, as part of the Saharan air layer, is transported at low levels by the monsoon flow, the Harmattan, the northeasterly trade winds, and the monsoon trough, and is transported upward in the convergence zone between Harmattan and monsoon flow, in the baroclinic zone along the West African coastline, and by convection. At around 700 hPa the dust is transported by the African easterly jet. Dry and dust-free air is found to the north-northwest of the developing tropical depression due to descent in an anticyclone. Based on the model data, it was possible to distinguish between dry (from the anticyclone), dry and dusty (from the Harmattan and northeasterly trade winds), and dusty and moist air (from the monsoon flow and in the tropical depression due to convection).

  9. An Interview with a Persistent Woman: Helen Farmer

    ERIC Educational Resources Information Center

    Harmon, Lenore W.

    2008-01-01

    An interview with Helen Farmer reveals the highlights of her professional life and the unusual road she took to her eventual position as a professor whose theories and mentoring of students have greatly influenced the field of counseling psychology. Also revealed are some of the personal qualities that led to her success. (Contains 1 note.)

  10. Eruptions of Mount St. Helens : Past, present, and future

    USGS Publications Warehouse

    Tilling, Robert I.; Topinka, Lyn J.; Swanson, Donald A.

    1990-01-01

    Mount St. Helens, located in southwestern Washington about 50 miles northeast of Portland, Oregon, is one of several lofty volcanic peaks that dominate the Cascade Range of the Pacific Northwest; the range extends from Mount Garibaldi in British Columbia, Canada, to Lassen Peak in northern California. Geologists call Mount St. Helens a composite volcano (or stratovolcano), a term for steepsided, often symmetrical cones constructed of alternating layers of lava flows, ash, and other volcanic debris. Composite volcanoes tend to erupt explosively and pose considerable danger to nearby life and property. In contrast, the gently sloping shield volcanoes, such as those in Hawaii, typically erupt nonexplosively, producing fluid lavas that can flow great distances from the active vents. Although Hawaiian-type eruptions may destroy property, they rarely cause death or injury. Before 1980, snow-capped, gracefully symmetrical Mount St. Helens was known as the "Fujiyama of America." Mount St. Helens, other active Cascade volcanoes, and those of Alaska form the North American segment of the circum-Pacific "Ring of Fire," a notorious zone that produces frequent, often destructive, earthquake and volcanic activity.

  11. Boise Inc. St. Helens Paper Mill Achieves Significant Fuel Savings

    SciTech Connect

    Not Available

    2008-05-01

    This case study describes how the Boise Inc. paper mill in St. Helens, Oregon, achieved annual savings of approximately 154,000 MMBtu and more than $1 million after receiving a DOE Save Energy Now energy assessment and implementing recommendations to improve the efficiency of its steam system.

  12. Boise Inc. St. Helens Paper Mill Achieves Significant Fuel Savings

    SciTech Connect

    2008-05-01

    This case study describes how the Boise Inc. paper mill in St. Helens, Oregon, achieved annual savings of approximately 154,000 MMBtu and more than $1 million. This was accomplished after receiving a DOE Save Energy Now energy assessment and implementing recommendations to improve the efficiency of its steam system.

  13. Learning from Mount St. Helens: Catastrophic Events as Educational Opportunities.

    ERIC Educational Resources Information Center

    Anderson, Jeremy

    1987-01-01

    Maintains that the study of catastrophic events should be given temporary precedence over the normal curriculum in order to help students understand the causes, consequences, and recovery alternatives, deal with trauma, and allay fear of recurrence and feelings of helplessness. Uses the May 1980 eruption of Mount St. Helens to demonstrate how…

  14. Mt. St. Helens Seen Close Up on May 18.

    ERIC Educational Resources Information Center

    Stoffel, Dorothy B.; Stoffel, Keith L.

    1980-01-01

    Describes eruption steps in Mt. St. Helens' top surface deformation: constant shaking of earthquakes, minor steaming from vents, and sudden catastrophic eruption. Explosions caused black projectile-laden ash clouds, vertical white steam clouds, and vertical gray ash-laden clouds. (SK)

  15. Blind Rage: An Open Letter to Helen Keller

    ERIC Educational Resources Information Center

    Kleege, Georgina

    2007-01-01

    In a letter addressed to Helen Keller, the author discusses the frustrations of being blind in the modern-day world. She reflects on the seeming pettiness of her complaints next to the difficulties Keller would have faced, especially given all of the new technologies and accommodations available to the blind. She wonders how Keller dealt with her…

  16. Stereo Pair, Mount St Helens, Washington State

    NASA Technical Reports Server (NTRS)

    2002-01-01

    On May 18, 1980, Mount St. Helens catastrophically erupted, causing the worst volcanic disaster in the recorded history of the United States. An earthquake shook loose the northern flank of the volcano, and about 2.8 cubic kilometers (0.67 cubic miles) of rock slid downslope in the world's largest recorded landslide. The avalanche released pressure on the volcano and unleashed a huge explosion, which was directed generally northward. The mountain ultimately lost 227 meters (1314 feet) of its height and devastated about 600 square kilometers (230 square miles) of forest.

    This stereoscopic view combines a Landsat satellite image with a Shuttle Radar Topography Mission elevation model to show the volcanic crater and most of the zone of devastation. Areas now relatively devoid of vegetation appear bright. Note the landslide debris clogging the northern drainages and forming natural dams (or enlarging previously existing ones). Also note the volcanic dome built up within the crater, and the extensive floating debris still present on Spirit Lake (northeast of the crater) 12 years after the eruption.

    This stereoscopic image was generated by draping a Landsat satellite image over a Shuttle Radar Topography Mission digital elevation model. Two differing perspectives were then calculated, one for each eye. They can be seen in 3-D by viewing the left image with the right eye and the right image with the left eye (cross-eyed viewing or by downloading and printing the image pair and viewing them with a stereoscope. When stereoscopically merged, the result is a vertically exaggerated view of Earth's surface in its full three dimensions.

    Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter (98-foot) resolution of most Landsat images and will substantially help in analyzing the large and growing Landsat image archive, managed by the U.S. Geological Survey (USGS).

    Elevation data used in this image was

  17. Anaglyph, Mount St Helens, Washington State

    NASA Technical Reports Server (NTRS)

    2002-01-01

    On May 18, 1980, Mount St. Helens catastrophically erupted, causing the worst volcanic disaster in the recorded history of the United States. An earthquake shook loose the northern flank of the volcano, and about 2.8 cubic kilometers (0.67 cubic miles) of rock slid downslope in the world's largest recorded landslide. The avalanche released pressure on the volcano and unleashed a huge explosion, which was directed generally northward. The mountain ultimately lost 227 meters (1314 feet) of its height and devastated about 600 square kilometers (230 square miles) of forest.

    This anaglyph combines a Landsat satellite image with a Shuttle Radar Topography Mission elevation model to show the volcanic crater and most of the zone of devastation. Areas now relatively devoid of vegetation appear bright. Note the landslide debris clogging the northern drainages and forming natural dams (or enlarging previously existing ones). Also note the volcanic dome built up within the crater, and the extensive floating debris still present on Spirit Lake (northeast of the crater) 12 years after the eruption.

    The stereoscopic effect of this anaglyph was created by first draping a Landsat satellite image over a digital elevation data from the Shuttle Radar Topography Mission (SRTM), and then generating two differing perspectives, one for each eye. When viewed through special glasses, the result is a vertically exaggerated view of the Earth's surface in its full three dimensions. Anaglyph glasses cover the left eye with a red filter and cover the right eye with a blue filter.

    Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter (98-foot)resolution of most Landsat images and will substantially help in analyzing the large and growing Landsat image archive, managed by the U.S. Geological Survey (USGS).

    Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space

  18. Effects of volcanism on the glaciers of Mount St. Helens

    USGS Publications Warehouse

    Brugman, Melinda M.; Post, Austin

    1981-01-01

    The cataclysmic eruption of Mount St. Helens May 18, 1980, removed 2.9 km2 (about 0.13 km3) of glacier snow and ice including a large part of Shoestring, Forsyth, Wishbone, Ape, Nelson, and all of Loowit and Leschi Glaciers. Minor eruptions and bulging of the volcano from March 27 to May 17 shattered glaciers which were on the deforming rock and deposited ash on other glaciers. Thick ash layers persisted after the May 18 eruption through the summer on most of the remaining snow and ice, and protected winter snow from melting on Swift and Dryer Glaciers. Melting and recrystalization of snow and ice surviving on Mount St. Helens could cause and lubricate mudflows and generate outburst floods. Study of glaciers that remain on this active volcano may assist in recognizing potential hazards on other volcanoes and lead to new contributions to knowledge of the transient response of glaciers to changes in mass balance or geometry.

  19. Sulfur dioxide content of Mount St. Helens' ash

    NASA Astrophysics Data System (ADS)

    Weschler, C. J.

    1984-06-01

    A rapid heating (980 C)-gas chromatographic-mass spectrometric technique was developed to measure the SO2 produced from Mount St. Helens' ash collected after the May 18, 1980, eruption. The average values of evolved SO2 for ash samples from Moses Lake, Missoula, and Helena are 215, 800, and 1250 ppm, respectively. The results suggest that the SO2 is associated primarily with new magmatic material. Experiments indicate that the SO2 is not due to sulfate species scavenged from the eruption plume or to sulfur gases adsorbed on the ash. Other possible sources include reduction of sulfate salts within the ash, bubbles of SO2 trapped within the ash, or sulfur blebs contained in the ash. Approximately as much SO2 or SO2 precursors are associated with the ash as Mount St. Helens' injected into the stratosphere.

  20. Helen Hart, remarkable plant pathologist (1900-1971).

    PubMed

    Wilcoxson, R D

    1996-01-01

    Helen Hart was a Professor of Plant Pathology at the University of Minnesota from 1924 until retirement in 1966. Born in Janeville, Wisconsin, she died at Grants Pass, Oregon. Her scholarly research concentrated on wheat stem rust to understand host pathogen relationships and to develop rust-resistant cultivars. She did not teach formal courses but was heavily involved in making seminars a vital part of instruction, in teaching languages needed for graduate studies, and as an informal advisor for most rust research theses. She had common sense, excellent scientific judgment, and sound instincts on personnel matters that served the department well. A talented science writer, Hart served as editor of hundreds of theses and departmental manuscripts for publication. Her writing and editing skills were used as associate editor of Phytopathology for two years and as editor-in-chief from 1944-1951. A strong advocate of The American Phytopathological Society, Helen Hart served on Council for 12 years and as President in 1956. Helen Hart was a great professional scientist who had a far-reaching impact on plant pathology during the twentieth century.

  1. Isolation and Analysis of Bacteria in Recreational Waters of the Chattahoochee River, Helen, GA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Helen is a tourism destination in the Appalachian Mountains. A popular activity during warm weather is tubing in the Chattahoochee River. This study was to determine the variety of bacteria in the Chattahoochee River in Helen, GA. Eight samples were collected during a 5km tubing trip down the Chatta...

  2. The Challenge of Advocacy: The Different Voices of Helen Keller and Burton Blatt.

    ERIC Educational Resources Information Center

    Smith, J. David

    1997-01-01

    Comparison of the different advocacy roles of Helen Keller and Burton Blatt finds that Helen Keller's role supports the belief in miracles resulting from unconditional and sustained commitments, whereas Burton Blatt's role illustrates the value of a commitment to human rights and human dignity regardless of any expectation of productivity or…

  3. Friendly Letters on the Correspondence of Helen Keller, Anne Sullivan, and Alexander Graham Bell.

    ERIC Educational Resources Information Center

    Blatt, Burton

    1985-01-01

    Excerpts from the letters between Alexander Graham Bell and Anne Sullivan and Helen Keller are given to illustrate the educational and personal growth of Helen Keller as well as the educational philosophy of Bell regarding the education of the deaf blind. (DB)

  4. Helene: The Face that Launched a Thousand Slips

    NASA Astrophysics Data System (ADS)

    Moore, J. M.; Howard, A. D.; Schenk, P.; Thomas, P. C.

    2013-12-01

    Helene, (~17.6 km mean radius) is a L4 Trojan co-orbital of Saturn's moon Dione. Its hemisphere features an unusual morphology consisting of broad depressions and a generally smooth surface patterned with streaks and grooves. The streaks appear to be oriented down-gradient, as are the grooves. This pattern suggests intensive mass-wasting as a dominant process on the leading hemisphere. Kilometer-scale impact craters are very sparse on the leading hemisphere other than the degraded km-scale basins defining the overall satellite shape, and many small craters have a diffuse appearance suggesting ongoing mass wasting. Thus mass wasting must dominate surface-modifying processes at present. In fact, the mass wasting appears to have been sufficient in magnitude to narrow the divides between adjacent basins to narrow septa, similar, but in lower relief, to the honeycomb pattern of Hyperion. The prominent groves occur primarily near topographic divides and appear have cut into a broad, slightly lower albedo surface largely conforming to the present topography but elevated a few meters above the smooth surfaces undergoing mass wasting flow. Low ridges and albedo markings on the surface suggest surface flow of materials traveling up to several kilometers. Diffusive mass wasting produces smooth surfaces - such a pattern characterizes most of the low-lying surfaces. The grooves, however, imply that the transport process is advective at those locations where they occur, that is, erosion tends to concentrate along linear pathways separated by divides. In fact, in many places grooves have a fairly regular spacing of 125-160 m, defining a characteristic erosional scale. Several questions are prompted by the unusual morphology of Helene: 1) What is the nature of the surface materials? 2) Are the transport processes gradual or catastrophic motion from one or a few events? 3) What mechanisms drive mass wasting and groove development? 4) Have the formative processes been active in the

  5. Geochemical Precursors to Volcanic Activity at Mount St. Helens, USA

    NASA Astrophysics Data System (ADS)

    Berlo, Kim; Blundy, Jon; Turner, Simon; Cashman, Kathy; Hawkesworth, Chris; Black, Stuart

    2004-11-01

    The importance of the interplay between degassing and crystallization before and after the eruption of Mount St. Helens (Washington, USA) in 1980 is well established. Here, we show that degassing occurred over a period of decades to days before eruptions and that the manner of degassing, as deduced from geochemical signatures within the magma, was characteristic of the eruptive style. Trace element (lithium) and short-lived radioactive isotope (lead-210 and radium-226) data show that ascending magma stalled within the conduit, leading to the accumulation of volatiles and the formation of lead-210 excesses, which signals the presence of degassing magma at depth.

  6. Regenerating the blast zone of Mount St. Helens

    SciTech Connect

    Winjum, J.K.; Keatley, J.E.; Stevens, R.G.; Gutzwiler, J.R.

    1986-05-01

    On May 18, 1980 an earthquake beneath the north side of Mt. St. Helens triggered the eruption of this volcano. This eruption caused damage to 160,000 acres of forests, meadows, lakes and streams. This paper discussed the reforestation of approximately 68,000 acres of commercial forest lands owned by Weyerhaeuser Company. This five year operation was the result of the cooperation of a team of research and operations foresters. The progress was reassuring but some areas will require more time before regeneration will be complete.

  7. Long-wave stratospheric transmission of Mount St. Helens ejecta

    NASA Technical Reports Server (NTRS)

    Kuhn, P. M.; Haughney, L. C.; Innis, R. C.

    1981-01-01

    The NASA/Ames Research C-141 aircraft underflew the Mount St. Helens ejecta plume in Utah three days after the eruption. Upward-looking 20-40-microns on-board radiometry provided data resulting in a calculated long-wave transmission of 0.93. From this value, an optical depth of 0.073 is inferred. This value is compared with an accepted background, stratospheric infrared optical depth of 0.06. Assumptions on particle size, shortwave albedo, and thermal warming imply little surface temperature change caused by the ejecta on the third day immediately following the eruption.

  8. Long-wave stratospheric transmission of Mount St. Helens ejecta.

    PubMed

    Kuhn, P M; Haughney, L C; Innis, R C

    1981-01-01

    The NASA/Ames Research C-141 aircraft underflew the Mount St. Helens ejecta plume in Utah three days after the eruption. Upward-looking 20-40-microm on-board radiometry provided data resulting in a calculated long-wave transmission of 0.93. From this value, an optical depth of 0.073 is inferred. This value is compared with an accepted background, stratospheric infrared optical depth of 0.06. Assumptions on particle size, shortwave albedo, and thermal warming imply little surface temperature change caused by the ejecta on the third day immediately following the eruption.

  9. Ecological Responses to the 1980 Eruption of Mount St. Helens

    NASA Astrophysics Data System (ADS)

    Dale, Virginia H.; Swanson, Frederick J.; Crisafulli, Charles M.

    The eruption of Mount St. Helens on May 18, 1980, had a momentous impact on the fungal, plant, animal, and human life from the mountain to the far reaches of the explosion's ash cloud and mudflows. Although this intense natural event caused loss of substantial life and property, it also created a unique opportunity to examine a huge disturbance of natural systems and their subsequent responses. Based on one of the most studied areas of volcanic activity, this book synthesizes the ecological research that has been conducted for twenty-five years since the eruption.

  10. Fluvial sedimentation following Quaternary eruptions of Mount St. Helens, Washington

    SciTech Connect

    Janda, R.J.; Meyer, D.F

    1985-01-01

    Depositional records of convulsive volcanic events at Mount St. Helens are in many places obscured by rapid fluvial erosion and deposition close to the volcano. Some major eruptions are recorded primarily by lahars and alluvium deposited tens of kilometers away. About 35 percent of the distinctive hummocky topography of the 1980 North Fork Toutle debris avalanche deposit now resembles an alluvial fan or a braided glacial outwash plain covered with 10 m or more of alluvium. Deposits of small (20 x 10/sup 6/m/sup 3/) but damaging lahars, such as those generated in the afternoon of 18 May 1980 and on 19 March 1982, have been largely eroded away. Rivers draining rapidly eroding areas surrounding Mount St. Helens presently have sediment yields that are among the highest in the world for nonglaciated streams of comparable size. These sediment loads are capable of causing aggradation-induced flooding in populated areas along the lower Toutle and Cowlitz Rivers. Sediment retention structures and dredging have prevented such flooding. Immediately following prehistoric eruptions, however, coarse-grained volcanic alluvium was deposited in the Cowlitz River to levels more than 1 m above the 1980 mud flow inundation level. Post-1980 rapid landscape modifications and high sediment yields are noteworthy because the eruption-impact area has not yet had a major regional storm and potentially catastrophic breachings of avalanche-impounded lakes have been prevented through engineering measures.

  11. Comparison between Dione' and Helene' surfaces using Cassini VIMS

    NASA Astrophysics Data System (ADS)

    Scipioni, F.; Tosi, F.; Capaccioni, F.; Cerroni, P.; Filacchione, G.; Federico, C.

    2012-04-01

    With 1122 km in diameter, Dione is the second largest inner moon of Saturn. The Voyager spacecrafts observed Dione in 1980 and revealed a complex surface structure. Afterwards, Dione was closely observed by the Cassini-Huygens spacecraft from 2004 to 2011. Dione's surface is composed primarily by water ice with minor abundances of volatiles such as CO2 and CN. The satellite's surface can be divided into some distinct classes: most notably, heavily cratered terrains and less cratered plains. Most of Dione's surface is covered by the heavily cratered terrains, located mainly in the trailing hemisphere and crossed by high-albedo wispy streaks. The origin of the dark material that covers the heavily cratered terrains is still unknown, while wispy units are likely tectonic features. Helene is a Dione's trojan moonlet, which orbits around Saturn in Dione's lagrangian point L4. The Visual and Infrared Mapping Spectrometer (VIMS) instrument onboard the Cassini Orbiter is able to acquire hyperspectral cubes in the overall spectral range from 0.35 to 5.1 μm. We have selected 76 VIMS cubes of Dione in the IR range between 0.85 and 5.1 μm. These data show at the same time a spatial resolution better than 100 km and a good S/N ratio. We have normalized all of the spectra at λ=2.23 μm in order to minimize photometric effects due to different observation conditions. To emphasize the existence of spectral units, we have applied the supervised clustering technique Spectral Angle Mapper (SAM) to the infrared spectra of each cube. A classification method applied to hyperspectral data shows up to be crucial to understand geochemical processes taking place on the icy satellites' surfaces, and, in this particular case, to investigate the possible presence on the surface of Dione of non water-ice materials, such as methane and ammonia. Some classes show also a peculiar trend with respect to the phase angle, possibly related to surface structure. Moreover, the use of this technique

  12. Observations of volcanic tremor at Mount St. Helens Volcano

    NASA Astrophysics Data System (ADS)

    Fehler, Michael

    1983-04-01

    Digital recordings of ground motion during tremor episodes accompanying eruptions at Mount St. Helens Volcano in the state of Washington on August 7 and October 16-18, 1980, are studied. The spectra of the vertical component waveforms contain at least two dominant peaks at 1.0 and 1.3 Hz for all events recorded during both eruptions that were studied. Spectra of horizontal ground motion show peaks at 0.9 and 1.1 Hz. The relative amplitude of the two peaks changes between tremor episodes and during single tremor episodes and shows no consistent relation to amplitude of ground motion. Spectra of long-period earthquakes are very similar to those of tremor events, suggesting that tremor is composed of many long-period earthquakes that occur over a period of time. The unique waveform of tremor events observed at Mount St. Helens must be due to a source effect, since the relative amplitude of the two dominant peaks changes during tremor episodes. The path effect on tremor waveforms is small since there are no peaks in the spectra of waveforms recorded during tectonic earthquakes occurring in the vicinity of Mount St. Helens. The consistency of the location of the spectral peaks for the wide range of tremor amplitudes means that there must be a physical length at the source that is constant, independent of the amplitude of motion at the source. Variations in amplitude of motion generated during tremor events must be due to variations in the force driving the tremor. Amplitudes of ground motion varies between 0.11 and 4.7 μm. Seismic moment rates during the two eruptions are calculated using the model of Aki et al. (1977) and found to vary between 6×1018 and 1×1020 dynes cm s-1, which are larger than values found by Aki et al. (1977), who studied amplitudes of shallow tremor events recorded during the October 1963 eruption of Kilauea volcano in Hawaii. Study of tremor amplitudes recorded at Corvallis, Oregon, leads to the conclusion that tremor accompanying the

  13. Deep long-period earthquakes (DLPs) beneath Mount St. Helens

    NASA Astrophysics Data System (ADS)

    Han, J.; Vidale, J. E.; Schmidt, D. A.; Creager, K. C.; Houston, H.

    2015-12-01

    The volcanic deep long-period earthquakes (DLPs) have been observed for a long time but remain poorly understood. Hypotheses associated with magmatic process have been proposed for the mechanisms of these DLPs, including dehydration embrittlement, flow of magma and/or magmatic fluid and cooling of magma. DLPs are commonly characterized by weak signal on the waveforms, deficiency in high-frequency energy, long-duration coda and their rare occurrence. They are located at 10-35 km depth, which are the mid- to lower-crust and/or uppermost mantle. The imaging Magma Under St Helens (iMUSH) experiment began in late June 2014, and since then the broadband seismometers have recorded six DLPs, two of which are also captured by dense array of Nodal stations. We use the iMUSH data and seismic data from nearby network stations to study the DLPs beneath St. Helens. Catalog DLPs are taken as templates to search for repeating events that might be too small to be detected otherwise. So far, we have searched for cross-station correlation detections for four template DLPs for the period 2007 to 2015. Three of the four seems to be isolated one-offs, while the fourth has at least 56 repetitions, three times more than were already in the catalog, and hints of many more. Many of the DLPs have several bursts within tens of seconds or several minutes. Overall the DLPs show an episodic activity with a period of roughly sixteen months. Several, but not all, episodes are temporally correlated with the subduction zone tremor activity west of St. Helens (Figure 1), which we are still investigating. We are locating these detections, and preliminary results suggest concentrated loci within a distance of one or two kilometers. We will conduct correlations between all detections, search farther back in time, and search with other templates as well, to better characterize their timeline and fine-scale geometry and analyze the waveforms to understand their physical mechanisms and the complicated

  14. [Helen of Troy and medicine, a picture of the "Salle des Actes"].

    PubMed

    Lafont, Olivier

    2012-05-01

    The picture of the 17th century, placed upon the great chimney in the "Salle des Actes", is attributed to the painter Simon Vouet or to his co-workers. It depicts a scene extracted from Odyssey by Homer. During their way-back to Greece, after the fall and the fire of Troia, Helen and Menelaus received in Egypt the famous nepenthes from the hands of Polydamna. An inventory of the possessions of the College of Pharmacy mentioned also helenium and moly. Nepenthes was really cited by Homer as a medicine used by Helen, but helenium was only related to Helen by euphony and moly referred to a totally different part of Odyssey and was not linked at all to Helen. This study points out the importance of mythology so far as origins of Pharmacy are concerned.

  15. [Helen of Troy and medicine, a picture of the "Salle des Actes"].

    PubMed

    Lafont, Olivier

    2012-05-01

    The picture of the 17th century, placed upon the great chimney in the "Salle des Actes", is attributed to the painter Simon Vouet or to his co-workers. It depicts a scene extracted from Odyssey by Homer. During their way-back to Greece, after the fall and the fire of Troia, Helen and Menelaus received in Egypt the famous nepenthes from the hands of Polydamna. An inventory of the possessions of the College of Pharmacy mentioned also helenium and moly. Nepenthes was really cited by Homer as a medicine used by Helen, but helenium was only related to Helen by euphony and moly referred to a totally different part of Odyssey and was not linked at all to Helen. This study points out the importance of mythology so far as origins of Pharmacy are concerned. PMID:23045808

  16. Patterns in Seismicity at Mt St Helens and Mt Unzen

    NASA Astrophysics Data System (ADS)

    Lamb, Oliver; De Angelis, Silvio; Lavallee, Yan

    2014-05-01

    Cyclic behaviour on a range of timescales is a well-documented feature of many dome-forming volcanoes. Previous work on Soufrière Hills volcano (Montserrat) and Volcán de Colima (Mexico) revealed broad-scale similarities in behaviour implying the potential to develop general physical models of sub-surface processes [1]. Using volcano-seismic data from Mt St Helens (USA) and Mt Unzen (Japan) this study explores parallels in long-term behaviour of seismicity at two dome-forming systems. Within the last twenty years both systems underwent extended dome-forming episodes accompanied by large Vulcanian explosions or dome collapses. This study uses a suite of quantitative and analytical techniques which can highlight differences or similarities in volcano seismic behaviour, and compare the behaviour to changes in activity during the eruptive episodes. Seismic events were automatically detected and characterized on a single short-period seismometer station located 1.5km from the 2004-2008 vent at Mt St Helens. A total of 714 826 individual events were identified from continuous recording of seismic data from 22 October 2004 to 28 February 2006 (average 60.2 events per hour) using a short-term/long-term average algorithm. An equivalent count will be produced from seismometer recordings over the later stages of the 1991-1995 eruption at MT Unzen. The event count time-series from Mt St Helens is then analysed using Multi-taper Method and the Short-Term Fourier Transform to explore temporal variations in activity. Preliminary analysis of seismicity from Mt St Helens suggests cyclic behaviour of subannual timescale, similar to that described at Volcán de Colima and Soufrière Hills volcano [1]. Frequency Index and waveform correlation tools will be implemented to analyse changes in the frequency content of the seismicity and to explore their relations to different phases of activity at the volcano. A single station approach is used to gain a fine-scale view of variations in

  17. Volatiles of Mount St. Helens and their origins

    USGS Publications Warehouse

    Barnes, I.

    1984-01-01

    Analyses have been made of gases in clouds apparently emanating from Mount St. Helens. Despite appearances, most of the water in these clouds does not issue from the volcano. Even directly above a large fumarole ??D and ?? 18O data indicate that only half the water can come from the volcano. Isotopic and chemical evidence also shows the steam in the volcano (-33.0 per mol ??D) from which a condensate of 0.2 N HCI was obtained is not a major cause of the explosions. The steam in the volcano is derived from a metamorphic brine in the underlying Tertiary meta andesite. The gas that caused the explosive eruptions is carbon dioxide. ?? 1984.

  18. Mount St. Helens: A 30-Year Legacy of Volcanism

    NASA Astrophysics Data System (ADS)

    Vallance, James W.; Gardner, Cynthia A.; Scott, William E.; Iverson, Richard M.; Pierson, Thomas C.

    2010-05-01

    The spectacular eruption of Mount St. Helens on 18 May 1980 electrified scientists and the public. Photodocumentation of the colossal landslide, directed blast, and ensuing eruption column—which reached as high as 25 kilometers in altitude and lasted for nearly 9 hours—made news worldwide. Reconnaissance of the devastation spurred efforts to understand the power and awe of those moments (Figure 1). The eruption remains a seminal historical event—studying it and its aftermath revolutionized the way scientists approach the field of volcanology. Not only was the eruption spectacular, but also it occurred in daytime, at an accessible volcano, in a country with the resources to transform disaster into scientific opportunity, amid a transformation in digital technology. Lives lost and the impact of the eruption on people and infrastructure downstream and downwind made it imperative for scientists to investigate events and work with communities to lessen losses from future eruptions.

  19. Characterization of aerosols from eruptions of Mount St. Helens

    SciTech Connect

    Chuan, R.L.; Woods, D.C.; McCormick, M.P.

    1981-01-01

    Measurements of mass concentration and size distribution of aerosols from eruptions of Mount St. Helens as well as morphological and elemental analyses were obtained between 7 April and 7 August 1980. In situ measurements were made in early phreatic and later, minor phreatomagmatic eruption clouds near the vent of the volcano and in plumes injected into the stratosphere from the major eruptions of 18 and 25 May. The phreatic aerosol was characterized by an essentially monomodal size distribution dominated by silicate particles larger than 10 micrometers in diameter. The phreatomagmatic eruption cloud was multimodal; the large size mode consisted of silicate particles and the small size modes were made up of mixtures of sulfuric acid and silicate particles. The stratospheric aerosol from the main eruption exhibited a characteristic narrow single mode with particles less than 1 micrometer in diameter and nearly all of the mass made up of sulfuric acid droplets.

  20. Mount St. Helens: A 30-year legacy of volcanism

    USGS Publications Warehouse

    Vallance, James W.; Gardner, Cynthia A.; Scott, William E.; Iverson, Richard M.; Pierson, Thomas C.

    2010-01-01

    The spectacular eruption of Mount St. Helens on 18 May 1980 electrified scientists and the public. Photodocumentation of the colossal landslide, directed blast, and ensuing eruption column—which reached as high as 25 kilometers in altitude and lasted for nearly 9 hours—made news worldwide. Reconnaissance of the devastation spurred efforts to understand the power and awe of those moments (Figure 1). The eruption remains a seminal historical event—studying it and its aftermath revolutionized the way scientists approach the field of volcanology. Not only was the eruption spectacular, but also it occurred in daytime, at an accessible volcano, in a country with the resources to transform disaster into scientific opportunity, amid a transformation in digital technology. Lives lost and the impact of the eruption on people and infrastructure downstream and downwind made it imperative for scientists to investigate events and work with communities to lessen losses from future eruptions.

  1. Characterization of aerosols from eruptions of mount st. Helens.

    PubMed

    Chuan, R L; Woods, D C; McCormick, M P

    1981-02-20

    Measurements of mass concentration and size distribution of aerosols from eruptions of Mount St. Helens as well as morphological and elemental analyses were obtained between 7 April and 7 August 1980. In situ measurements were made in early phreatic and later, minor phreatomagmatic eruption clouds near the vent of the volcano and in plumes injected into the stratosphere from the major eruptions of 18 and 25 May. The phreatic aerosol was characterized by an essentially monomodal size distribution dominated by silicate particles larger than 10 micrometers in diameter. The phreatomagmatic eruption cloud was multimodal; the large size mode consisted of silicate particles and the small size modes were made up of mixtures of sulfuric acid and silicate particles. The stratospheric aerosol from the main eruption exhibited a characteristic narrow single mode with particles less than 1 micrometer in diameter and nearly all of the mass made up of sulfuric acid droplets.

  2. The isotopic and chemical evolution of Mount St. Helens

    USGS Publications Warehouse

    Halliday, A.N.; Fallick, A.E.; Dickin, A.P.; Mackenzie, A.B.; Stephens, W.E.; Hildreth, W.

    1983-01-01

    Isotopic and major and trace element analysis of nine samples of eruptive products spanning the history of the Mt. St. Helens volcano suggest three different episodes; (1) 40,000-2500 years ago: eruptions of dacite with ??{lunate}Nd = +5, ??{lunate}Sr = -10, variable ??18O, 206Pb/204Pb ??? 18.76, Ca/Sr ??? 60, Rb/Ba ??? 0.1, La/Yb ??? 18, (2) 2500-1000 years ago: eruptions of basalt, andesite and dacite with ??{lunate}Nd = +4 to +8, ??{lunate}Sr = -7 to -22, variable ??18O (thought to represent melting of differing mantle-crust reservoirs), 206Pb/204Pb = 18.81-18.87, variable Ca/Sr, Rb/Ba, La/Yb and high Zr, (3) 1000 years ago to present day: eruptions of andesite and dacite with ??{lunate}Nd = +6, ??{lunate}Sr = -13, ??18O ???6???, variable 206Pb/204Pb, Ca/Sr ??? 77, Rb/Ba = 0.1, La/Yb ??? 11. None of the products exhibit Eu anomalies and all are LREE enriched. There is a strong correlation between 87Sr/86Sr and differentiation indices. These data are interpreted in terms of a mantle heat source melting young crust bearing zircon and garnet, but not feldspar, followed by intrusion of this crustal reservoir by mantle-derived magma which caused further crustal melting and contaminated the crustal magma system with mafic components. Since 1000 years ago all the eruptions have been from the same reservoir which has displayed a much more gradual re-equilibration of Pb isotopic compositions than other components suggesting that Pb is being transported via a fluid phase. The Nd and Sr isotopic compositions lie along the mantle array and suggest that the mantle underneath Mt. St. Helens is not as depleted as MORB sources. There is no indication of seawater involvement in the source region. ?? 1983.

  3. Road guide to volcanic deposits of Mount St. Helens and vicinity, Washington

    SciTech Connect

    Doukas, M.P.

    1990-01-01

    Mount St. Helens, the most recently active and most intensively studied Cascade volcano, is located in southwestern Washington. The volcano is a superb outdoor laboratory for studying volcanic processes, deposits of observed events, and deposits whose origins are inferred by classic geologic techniques, including analogy to Recent deposits. This road log is a guide to Mount St. Helens Volcano, with emphasis on effects and deposits of the 1980 eruption.

  4. Catastrophic eruptions of the directed-blast type at Mount St. Helens, bezymianny and Shiveluch volcanoes

    USGS Publications Warehouse

    Bogoyavlenskaya, G.E.; Braitseva, O.A.; Melekestsev, I.V.; Kiriyanov, V. Yu; Dan, Miller C.

    1985-01-01

    This paper describes catastrophic eruptions of Mount St. Helens (1980), Bezymianny (1955-1956), and Shiveluch (1964) volcanoes. A detailed description of eruption stages and their products, as well as the quantitative characteristics of the eruptive process are given. The eruptions under study belong to the directed-blast type. This type is characterized by the catastrophic character of the climatic stage during which a directed blast, accompanied by edifice destruction, the profound ejection of juvenile pyroclastics and the formation of pyroclastic flows, occur. The climatic stage of all three eruptions has similar characteristics, such as duration, kinetic energy of blast (1017-1018 J), the initial velocity of debris ejection, morphology and size of newly-formed craters. But there are also certain differences. At Mount St. Helens the directed blast was preceeded by failure of the edifice and these events produced separable deposits, namely debris avalanche and directed blast deposits which are composed of different materials and have different volumes, thickness and distribution. At Bezymianny, failure did not precede the blast and the whole mass of debris of the old edifice was outburst only by blast. The resulting deposits, represented by the directed blast agglomerate and sand facies, have characteristics of both the debris avalanche and the blast deposit at Mount St. Helens. At Shiveluch directed-blast deposits are represented only by the directed-blast agglomerate; the directed-blast sand facies, or blast proper, seen at Mount St. Helens is absent. During the period of Plinian activity, the total volumes of juvenile material erupted at Mount St. Helens and at Besymianny were roughly comparable and exceeded the volume of juvenile material erupted at Shiveluch, However, the volume of pyroclastic-flow deposits erupted at Mount St. Helens was much less. The heat energy of all three eruptions is comparable: 1.3 ?? 1018, 3.8-4.8 ?? 1018 and 1 ?? 1017 J for

  5. Hydrology of the Castle Lake blockage, Mount St Helens, Washington

    USGS Publications Warehouse

    Meyer, William; Sabol, M.A.

    1989-01-01

    The debris avalanche that occurred during the May 19, 1980, eruption of Mount St. Helens blocked South Fork Castle Creek and created Castle Lake. Stability of the blockage was of concern, and a digital model that simulates three-dimensional groundwater movement in the blockage was constructed as part of the analysis used in a follow-up study that assessed the blockage 's stability. Slug test results in the debris avalanche deposits and model results indicate that the average horizontal hydraulic conductivity of the blockage material is approximately 2.5 ft/day, whereas the ratio of horizontal to vertical hydraulic conductivity is approximately 10 to 1. The model was calibrated to seasonally high groundwater levels and groundwater discharge. Model-predicted recharge rates for this time period were 0.97 cu ft/sec. Most of the recharge (81%) results from the infiltration of precipitation, whereas discharge by seeps through the blockage accounts for 81% of the total discharge. Because water levels under the crest of the blockage are higher than lake level, the movement of groundwater is toward the lake and the toe of the blockage. The model allows the water levels to be estimated at any location in the blockage. This information is required for making estimates of the stability of the blockage against failure by gravitational-induced or earthquake-induced slope failure, liquefaction, the process of seepage erosion, or by erosion. (Lantz-PTT)

  6. Geologic Map of the Helen Planitia Quadrangle (V-52), Venus

    USGS Publications Warehouse

    Lopez, Ivan; Hansen, Vicki L.

    2008-01-01

    The Magellan spacecraft orbited Venus from August 10, 1990, until it plunged into the Venusian atmosphere on October 12, 1994. Magellan Mission objectives included (1) improving the knowledge of the geological processes, surface properties, and geologic history of Venus by analysis of surface radar characteristics, topography, and morphology and (2) improving the knowledge of the geophysics of Venus by analysis of Venusian gravity. The Helen Planitia quadrangle (V-52), located in the southern hemisphere of Venus between lat 25 deg S. and 50 deg S. and between long 240 deg E. and 270 deg E., covers approximately 8,000,000 km2. Regionally, the map area is located at the southern limit of an area of enhanced tectonomagmatic activity and extensional deformation, marked by a triangle that has highland apexes at Beta, Atla, and Themis Regiones (BAT anomaly) and is connected by the large extensional belts of Devana, Hecate, and Parga Chasmata. The BAT anomaly covers approximately 20 percent of the Venusian surface.

  7. Reestablishment of endogonaceae on Mount St. Helens: survival of residuals

    SciTech Connect

    Allen, M.F.; MacMahon, J.A.; Andersen, D.C.

    1984-01-01

    The 18 May 1980 eruption of Mount St. Helens resulted in the burial of relatively well developed soils under variable depths of sterile tephra and ash. During summer 1982, we examined a series of sites and estimated the numbers of spores of Endogonaceae that had been transported from the buried soil to the new ground surface by either abiotic or biotic vectors. There was no difference between spore counts of Endogone spp. or Glomus spp. in the buried soils of forests and clear-cuts; spores were rare in the tephra at any site. In areas featuring less than or equal to 50 cm of tephra, spores were transported to the surface by gophers (in previous clear-cut areas) and by ants (in previous forest and clear-cut habitats). In the Pumice Plain, an area devoid of gophers and ants, erosion exposed spores to the surface. We found no evidence to suggest that endogonaceous fungi grow back up root systems from buried horizons. We hypothesize that small-scale perturbations (erosion, gopher and ant mounds) following the major volcanic disturbance may drive succession by exposing buried mycorrhizal and decomposer fungi. 26 references, 2 figures, 3 tables.

  8. Analysis of Mount St. Helens ash from optical photoelectric photometry

    NASA Technical Reports Server (NTRS)

    Cardelli, J. A.; Ackerman, T. P.

    1983-01-01

    The optical properties of suspended dust particles from the eruption of Mt. St. Helens on July 23, 1980 are investigated using photoelectric observations of standard stars obtained on the 0.76-m telescope at the University of Washington 48 hours after the eruption. Measurements were made with five broad-band filters centered at 3910, 5085, 5480, 6330, and 8050 A on stars of varying color and over a wide range of air masses. Anomalous extinction effects due to the volcanic ash were detected, and a significant change in the wavelength-dependent extinction parameter during the course of the observations was established by statistical analysis. Mean particle size (a) and column density (N) are estimated using the Mie theory, assuming a log-normal particle-size distribution: a = 0.18 micron throughout; N = 1.02 x 10 to the 9th/sq cm before 7:00 UT and 2.33 x 10 to the 9th/sq cm after 8:30 UT on July 25, 1980. The extinction is attributed to low-level, slowly migrating ash, possibly combined with products of gas-to-particle conversion and coagulation.

  9. Improving the intensity of the HELEN Laser at AWE

    NASA Astrophysics Data System (ADS)

    Hopps, Nicholas; Nolan, Jonathan; Girling, Mark; Kopec, Maria; Harvey, Ewan

    2005-04-01

    The HELEN laser is a three-beam, large aperture Nd:glass laser, used for plasma physics studies at the Atomic Weapons Establishment in the UK. Two of the beams nominally deliver 500 J each in 1 ns at the second harmonic (527 nm). The third beam, the "backlighter", has recently been upgraded to operate as a chirped pulse amplification system and it now routinely delivers 70 J to target in 500 fs. Optimal focal spot performance is achieved using a closed-loop adaptive optics system, which ensures good wavefront characteristics, irrespective of whether previous firing of the amplifiers has induced refractive index variations in the laser glass. The system uses a 32 element bimorph mirror with 98 mm aperture, roughly half way through the laser chain. A Shack-Hartman wavefront sensor, positioned at the output of the laser is the diagnostic used to provide feedback to the deformable mirror. Correction of the static and slowly varying aberrations on the beam has been demonstrated. The fast aberrations induced during the flashlamp discharge have been evaluated. The improved focal spot characteristics result in an intensity on target of significantly greater than 1019 Wcm-2.

  10. Field weathering rates of Mt. St. Helens tephra

    NASA Astrophysics Data System (ADS)

    Dahlgren, R. A.; Ugolini, F. C.; Casey, W. H.

    1999-03-01

    The initial stages of chemical weathering in tephra were examined under field conditions in a cool and humid forest ecosystem in the Cascade Mountains of Washington. Unleached tephra from the 1980 eruption of Mt. St. Helens was applied in 5 cm and 15 cm depths to simulate natural tephra deposition. Leachate solutions from the tephra were then collected and analyzed over a 4 year period. Concentrations of dissolved elements were combined with the water fluxes to determine elemental fluxes from tephra and to estimate chemical weathering rates. Solutions leached from the tephra layer indicate incongruent dissolution resulting in formation of a cation-depleted, silica-rich leached layer on glass and mineral surfaces. Measured weathering rates were 1-3 orders of magnitude less than comparable rates reported in the literature for laboratory dissolution studies, but considerably greater than those measured for entire watersheds in field studies. Dissociation of carbonic acid, originating primarily from upward transport of carbon dioxide from the buried soil, was the dominant source of protons for weathering reactions. Weathering rates in the 5 cm treatment were approximately twice those of the 15 cm treatment. A greater flux of CO 2 per unit volume of tephra in the 5 cm treatment is believed to be responsible for the differential weathering rates.

  11. Surtsey and Mount St. Helens: a comparison of early succession rates

    NASA Astrophysics Data System (ADS)

    del Moral, R.; Magnússon, B.

    2014-04-01

    Surtsey and Mount St. Helens are celebrated but very different volcanoes. Permanent plots allow for comparisons that reveal mechanisms that control succession and its rate and suggest general principles. We estimated rates from structure development, species composition using detrended correspondence analysis (DCA), changes in Euclidean distance (ED) of DCA vectors, and by principal components analysis (PCA) of DCA. On Surtsey, rates determined from DCA trajectory analyses decreased as follows: gull colony on lava with sand > gull colony on lava, no sand ≫ lava with sand > sand spit > block lava > tephra. On Mount St. Helens, plots on lahar deposits near woodlands were best developed. The succession rates of open meadows declined as follows: Lupinus-dominated pumice > protected ridge with Lupinus > other pumice and blasted sites > isolated lahar meadows > barren plain. Despite the prominent contrasts between the volcanoes, we found several common themes. Isolation restricted the number of colonists on Surtsey and to a lesser degree on Mount St. Helens. Nutrient input from outside the system was crucial. On Surtsey, seabirds fashioned very fertile substrates, while on Mount St. Helens wind brought a sparse nutrient rain, then Lupinus enhanced fertility to promote succession. Environmental stress limits succession in both cases. On Surtsey, bare lava, compacted tephra and infertile sands restrict development. On Mount St. Helens, exposure to wind and infertility slow succession.

  12. Surtsey and Mount St. Helens: a comparison of early succession rates

    NASA Astrophysics Data System (ADS)

    del Moral, R.; Magnússon, B.

    2013-12-01

    Surtsey and Mount St. Helens are celebrated, but very different volcanoes. Permanent plots allow comparisons that reveal mechanisms that control succession and its rate and suggest general principles. We estimated rates from structure development, species composition using detrended correspondence analysis (DCA), changes in Euclidean distance (ED) of DCA vectors and by principal components analysis (PCA) of DCA. On Surtsey, rates determined from DCA trajectory analyses decreased as follows: gull colony on lava with sand > gull colony on lava, no sand ≫ lava with sand > sand spit > block lava > tephra. On Mount St. Helens, plots on lahar deposits near woodlands were best developed. The succession rates of open meadows declined as follows: Lupinus-dominated pumice > protected ridge with Lupinus > other pumice and blasted sites > isolated lahar meadows > barren plain. Despite the prominent contrasts between the volcanoes, common themes were revealed. Isolation restricted the number of colonists on Surtsey and to a lesser degree on Mount St. Helens. Nutrient input from outside the system was crucial. On Surtsey, seabirds fashioned very fertile substrates, while on Mount St. Helens wind brought a sparse nutrient rain, then Lupinus enhanced fertility to promote succession. Environmental stress limits succession in both cases. On Surtsey, bare lava, compacted tephra and infertile sands restrict development. On Mount St. Helens, exposure to wind and infertility slow succession.

  13. Inclusions in Mount St. Helens dacite erupted from 1980 through 1983

    USGS Publications Warehouse

    Heliker, C.

    1995-01-01

    Inclusions of plutonic, metavolcanic and volcanic rocks are abundant in dacite pumice and lava from the 1980-1986 eruption sequence at Mount St. Helens. Point counts of inclusions exposed in talus blocks from the dome from 1980 through 1983 show that inclusions form approximately 3.5 vol.% of the lava. Eighty-five percent of the inclusions are medium-grained gabbros. The gabbroic inclusions are of four distinct type. The most abundant type is laminated gabbronorite. Various types of gabbroic inclusions, including the laminated gabbronorite, are common in Mount St. Helens lavas of approximately the last 3000 years. This coincides with the interval in which Mount St. Helens first erupted basalt and basaltic andesite lavas. These observations, together with the fact that the gabbroic inclusions are compositionally unlike any of the Tertiary intrusive rocks in the Mount St. Helens area, strongly suggest that the inclusions are related to the introduction of basalt to the Mount St. Helens magmatic system. -from Author

  14. The "Unsavory Researches" of Helen Campbell: A 19th-Century Journalist's Investigation of Urban Women's Poverty.

    ERIC Educational Resources Information Center

    Henry, Susan

    In 1886, the New York "Tribune" ran a series of articles by Helen Campbell, "The Prisoners of Poverty," which investigated the sufferings of working women in New York's slums. Initially a fiction and housekeeping writer, Helen Campbell's home economics orientation first pointed her toward the problems of the poor. In the late 1870s, she wrote a…

  15. Road guide to volcanic deposits of Mount St. Helens and vicinity, Washington

    USGS Publications Warehouse

    Doukas, Michael P.

    1990-01-01

    Mount St. Helens, the most recently active and most intensively studied Cascades volcano, is in southwestern Washington. The volcano is a superb outdoor laboratory for studying volcanic processes, deposits of observed events, and deposits whose origins are inferred by classic geologic techniques, including analogy to recent deposits. During the past 4,500 years, Mount St. Helens has been more active and more explosive than any other volcano in the conterminous United States. Mount St. Helens became active in mid-March 1980, and eruptive activity began on March 27. Since the climactic eruption of May 18, 1980, the volcano has continued to be active at least until 1988. The 1890 activity of Mount St. Helens is summarized in U.S. Geological Survey Professional Papers 1249 and 1250. This road guide is a tour of Mount St. Helens volcano and vicinity, with emphasis on the effects and deposits of the 1980 eruption. The road log starts from the U.S. Geological Survey's David A. Johnston Cascades Volcano Observatory, Vancouver, Washington. The guide is organized around two primary routes. LEG I is on paved and gravel roads from Vancouver to areas east of Mount St. Helens, including Windy Ridge Overlook near Spirit Lake. This is possibly the most scenic route described in the guide, including a transect of the devastated zone of May 18, 1980, Spirit Lake, and numerous vistas of the volcano. LEG II leads to areas west of the volcano from Vancouver via U.S. Interstate Highway 5, then on a paved ... road along the Toutle River. Highlights include the spectacular effects of mudflows and a view of the huge debris-avalanche deposit that was formed on May 18, 1980.

  16. Comparative physiographic diagrams of Mount St. Helens, Washington, and Crater Lake, Oregon

    USGS Publications Warehouse

    Alpha, Tau Rho; Morley, Jim M.

    1983-01-01

    These physiographic diagrams provide a visual comparison of two Cascade Range volcanoes which have had their tops destroyed in different ways -- Mount St. Helens in 1980, Mount Mazama (whose site is now occupied by Crater Lake) about 6,800 years ago. Both volcanoes are viewed from the north from 30 degrees above the horizon, with no vertical exaggeration. The ground area portrayed in each diagram is equal; the south edge of the Mount St. Helens drawing is lower than that of Crater Lake drawing because elevations drop away toward the south, whereas elevations are more constant at the north and south edges of the Crater Lake diagram. 

  17. Counting, accounting, and accountability: Helen Verran's relational empiricism.

    PubMed

    Kenney, Martha

    2015-10-01

    Helen Verran uses the term 'relational empiricism' to describe situated empirical inquiry that is attentive to the relations that constitute its objects of study, including the investigator's own practices. Relational empiricism draws on and reconfigures Science and Technology Studies' traditional concerns with reflexivity and relationality, casting empirical inquiry as an important and non-innocent world-making practice. Through a reading of Verran's postcolonial projects in Nigeria and Australia, this article develops a concept of empirical and political 'accountability' to complement her relational empiricism. In Science and an African Logic, Verran provides accounts of the relations that materialize her empirical objects. These accounts work to decompose her original objects, generating new objects that are more promising for the specific postcolonial contexts of her work. The process of decomposition is part of remaining accountable for her research methods and accountable to the worlds she is working in and writing about. This is a practice of narrating relations and learning to tell better technoscientific stories. What counts as better, however, is not given, but is always contextual and at stake. In this way, Verran acts not as participant-observer, but as participant-storyteller, telling stories to facilitate epistemic flourishing within and as part of a historically located community of practice. The understanding of accountability that emerges from this discussion is designed as a contribution, both practical and evocative, to the theoretical toolkit of Science and Technology Studies scholars who are interested in thinking concretely about how we can be more accountable to the worlds we study.

  18. Counting, accounting, and accountability: Helen Verran's relational empiricism.

    PubMed

    Kenney, Martha

    2015-10-01

    Helen Verran uses the term 'relational empiricism' to describe situated empirical inquiry that is attentive to the relations that constitute its objects of study, including the investigator's own practices. Relational empiricism draws on and reconfigures Science and Technology Studies' traditional concerns with reflexivity and relationality, casting empirical inquiry as an important and non-innocent world-making practice. Through a reading of Verran's postcolonial projects in Nigeria and Australia, this article develops a concept of empirical and political 'accountability' to complement her relational empiricism. In Science and an African Logic, Verran provides accounts of the relations that materialize her empirical objects. These accounts work to decompose her original objects, generating new objects that are more promising for the specific postcolonial contexts of her work. The process of decomposition is part of remaining accountable for her research methods and accountable to the worlds she is working in and writing about. This is a practice of narrating relations and learning to tell better technoscientific stories. What counts as better, however, is not given, but is always contextual and at stake. In this way, Verran acts not as participant-observer, but as participant-storyteller, telling stories to facilitate epistemic flourishing within and as part of a historically located community of practice. The understanding of accountability that emerges from this discussion is designed as a contribution, both practical and evocative, to the theoretical toolkit of Science and Technology Studies scholars who are interested in thinking concretely about how we can be more accountable to the worlds we study. PMID:26630820

  19. Two cases of induced insanity. Helene Deutsch, Cambridge, Mass.

    PubMed

    Roazen, P

    1981-01-01

    "Two cases of induced insanity", hitherto untranslated, was Helene Deutsch's first (1918) psychoanalytic paper; she presented Freud with a copy of it during the beginning of her analysis with him. As an experienced clinician who had studied under both Wagner von Jauregg in Vienna and Emil Kraepelin in Munich, Deutsch observed these cases during World War I as the University of Vienna's psychiatric facilities. Although the general reading public knows her best for her The Psychology of Women, she also wrote some well-known clinical papers; and it is characteristic of her that she brought these two cases without excessive theoretical speculation. In "Two cases in induced insanity" Deutsch described some of the strains of the wartime situation, and how whole families could join in hysterical confabulations in order to cope with emotional distress. One of her most famous later clinical contribution had to do with the emotional impoverishment of 'as if' personalities and their specific suggestibility. In other papers she continued her early concern with disturbed identification. As one examines Deutsch's work it is possible to fill out the history of psychoanalytic psychology. Without ignoring her later increase in theoretical sophistication, in "Two cases of induced insanity" we find Deutsch remarkably tolerant in her willingness to suspend judgement about the sources and fate of morbid thinking. A key therapeutic recommendation of hers was to separate the family members to allow their reality to return. Like some recent critics of undue diagnostic name-calling she advocated hesitation in discerning of disease entities as well as cautionary approach to treatment. The nature of familial love may leave everyone "normal" prone to disturbances which are not necessarily to be treated as a psychiatric illness. This example of one of Deutsch's first professional essays reflects the early thinking of a giant in psychoanalysis. She followed Freud in the conviction that the

  20. Physical and chemical characteristics of Mt. St. Helens airborne debris

    SciTech Connect

    Sedlacek, W.A.; Heiken, G.H.; Mroz, E.J.; Gladney, E.S.; Perrin, D.R.; Leifer, R.; Fisenne, I.; Hinchliffe, L.; Chuan, R.L.

    1980-01-01

    Tephra and aerosols from the May 18, 1980 eruption of Mt. St. Helens, Washington were sampled in the lower stratosphere with a WB-57F aircraft. The main body of the plume was intercepted over western Kansas on May 20, 48 hours after the eruption, at an altitude of 15.2 km. Concentrations on filter samples were 26 ng of SO/sub 4//g of air and 579 ng of ash/g of air. Angular glass pyroclasts ranged in size from 0.5 to 10 ..mu..m, with a mean grain size of 2 ..mu..m. Samples collected at altitudes of 16.7 and 12.5 km had only traces of SO/sub 4/ and ash. A second flight was flown, 72 hours after the eruption, on May 21. From north Texas to central Wyoming, at an altitude of 15.2 km, < 0.5 to 38 ng of ash/g of air and 1.0 to 2.2 ng of SO/sub 4//g of air were sampled. At an altitude of 18.3 km, from central Wyoming to NW New Mexico, the plume density and character were variable. Glassy pyroclasts similar to those sampled on the first flight range in size from 0.5 to 4 ..mu..m dia. Trace element analysis revealed some volatile element enrichment, but far less than previously observed in the plume from St. Augustine Volcano, 1976. Values of /sup 210/Po//sup 210/Pb were 0.7 to 1.32 comparable to the secular equilibrium value of 1.0 and far less than ratios previously reported by Lambert.

  1. Meet Helen J. Post-Brown, Director: Sunbeam Child Care Center, Fairmont, West Virginia

    ERIC Educational Resources Information Center

    Exchange: The Early Childhood Leaders' Magazine Since 1978, 2005

    2005-01-01

    This article profiles Helen J. Post-Brown, director of Sunbeam Child Care Center in Fairmont and president of West Virginia Childcare Centers United, and explains how Post-Brown faced the obstacles when managing a child care business. In the fall of 1980, Post-Brown started Sunbeam as a small preschool with 12 children. Over the years, Sunbeam has…

  2. Attenuation of terrestrial solar radiation by the eruption of Mt. St. Helens

    NASA Astrophysics Data System (ADS)

    Howard, R. G.

    1981-02-01

    Incident solar radiation attenuation due to the May 18, 1980 Mt. St. Helens eruption was measured by PSP pyranometers. Graphs are presented on the attenuation due to the ash cloud that passed over Richland, Washington, and over Billings, Montana the same day at different hours.

  3. Atmospheric Effects and Potential Climatic Impact of the 1980 Eruptions of Mount St. Helens

    NASA Technical Reports Server (NTRS)

    Deepak, A. (Editor)

    1982-01-01

    Measurements and studies of the 1980 Mount St. Helens volcanic eruptions and their atmospheric effects and climatic impact are addressed. Specific areas discussed include: (1) nature and impact of volcanic eruptions; (2) in situ measurements of effluents; (3) remote sensing measurements; (4) transport and dispersion of volcanic effluents; (5) chemistry of volcanic effluents; and (6) weather and potential climate impact.

  4. Multipass reconfiguration of the HELEN Nd:glass laser at the Atomic Weapons Establishment.

    PubMed

    Norman, Michael J; Andrew, James E; Bett, Thomas H; Clifford, Roger K; England, John E; Hopps, Nicholas W; Parker, Kenneth W; Porter, Kenneth; Stevenson, Mark

    2002-06-20

    The HELEN high-power Nd:glass laser has been rebuilt in a new multipass configuration that requires fewer components to maintain existing performance. This is expected to lead to greater system availability and reduced running costs. We describe the new design, discuss some of the key issues that had to be addressed, and present operational results. PMID:12078672

  5. Contingency Planning for Natural Disasters: The Mount St. Helens Experience. AIR Forum 1981 Paper.

    ERIC Educational Resources Information Center

    Burns, James A.; Concordia, Louis R.

    The effectiveness of existing contingency planning efforts at five community colleges, three colleges, and five universities during the Mount St. Helens eruptions in 1980 in Washington state was assessed. Planning efforts in the areas of institutional policy, academic policy, business office, physical plant, residence halls, financial aid, and…

  6. Using Microcomputer Game-Simulation Experiments to Study Family Response to Mt. St. Helens Eruptions.

    ERIC Educational Resources Information Center

    Ekker, Knut; And Others

    1988-01-01

    Explains how computerized game-simulation experiments were conducted to ascertain responses to the 1980 eruptions of Mt. St. Helens (Washington). Results indicate different aspects of individual preferences and family decisions with respect to relocation: (1) highly consistent in the game simulation; (2) responsive to the simulated threat; and (3)…

  7. Multipass reconfiguration of the HELEN Nd:glass laser at the Atomic Weapons Establishment.

    PubMed

    Norman, Michael J; Andrew, James E; Bett, Thomas H; Clifford, Roger K; England, John E; Hopps, Nicholas W; Parker, Kenneth W; Porter, Kenneth; Stevenson, Mark

    2002-06-20

    The HELEN high-power Nd:glass laser has been rebuilt in a new multipass configuration that requires fewer components to maintain existing performance. This is expected to lead to greater system availability and reduced running costs. We describe the new design, discuss some of the key issues that had to be addressed, and present operational results.

  8. Evolution of Crater Glacier, Mount St. Helens, Washington, September 2006-November 2009

    USGS Publications Warehouse

    Walder, Joseph S.; Schilling, Steven P.; Sherrod, David R.; Vallance, James W.

    2010-01-01

    Lava-dome emplacement through a glacier was observed for the first time during the 2004-08 eruption of Mount St. Helens and documented using photography, photogrammetry, and geodetic measurements. Previously published reports present such documentation through September 2006; this report extends that documentation until November 2009.

  9. Multipass reconfiguration of the HELEN Nd:glass laser at the Atomic Weapons Establishment

    NASA Astrophysics Data System (ADS)

    Norman, Michael J.; Andrew, James E.; Bett, Thomas H.; Clifford, Roger K.; England, John E.; Hopps, Nicholas W.; Parker, Kenneth W.; Porter, Kenneth; Stevenson, Mark

    2002-06-01

    The HELEN high-power Nd:glass laser has been rebuilt in a new multipass configuration that requires fewer components to maintain existing performance. This is expected to lead to greater system availability and reduced running costs. We describe the new design, discuss some of the key issues that had to be addressed, and present operational results.

  10. The Larry Jarret House Program at the Helen Beebe Speech and Hearing Center.

    ERIC Educational Resources Information Center

    Goldberg, Donald M.; Talbot, Pamela J.

    1993-01-01

    The Larry Jarret House is a one-week in-residence program of the Helen Beebe Speech and Hearing Center in Easton, Pennsylvania, for parents of children with hearing impairments. The program is designed to help parents maximize their child's use of residual hearing in daily life situations to develop spoken language. (JDD)

  11. [100th anniversary of the Oskar-Helene-Heim - an obituary].

    PubMed

    Jüttemann, A

    2014-12-01

    The Oskar-Helene-Heim is one of the birthplaces of German orthopaedic clinics. The clinic was demolished in winter 2013/2014. Almost all of the historic buildings of the traditional specialist hospital in south-west Berlin were torn down in in the preparation for a housing project. The history of this facility is briefly described in this article. PMID:25531517

  12. The structure, dynamics, and chemical composition of noneruptive plumes from Mount St. Helens, 1980-1988

    USGS Publications Warehouse

    McGee, K.A.

    1992-01-01

    From May 1980 to September 1988, more than 1000 fixed-wing aircraft flights were made with a correlation spectrometer to measure the sulfur dioxide flux from Mount St. Helens volcano. These flights also provided valuable data on the structure and dynamics of noneruptive plumes emanating from Mount St. Helens. During 1980 and part of 1981, an infrared spectrometer was also used to measure carbon dioxide emission rates. At distances up to 25 km from Mount St. Helens, plume widths can range up to 20 km or more, with width/thickness ratios from 3 to about 30. Maximum sulfur dioxide concentrations in these plumes depend on wind speed and are typically under 5 ppm and usually 1 ppm or less. Close examination of the plume data reveals that the characteristics of quiescent plumes from Mount St. Helens are strongly affected by certain meteorological conditions such as thermal and wind stratification in the troposphere, as well as by the topography of the volcano. ?? 1992.

  13. Deposits of large volcanic debris avalanches at Mount St. Helens and Mount Shasta volcanoes

    SciTech Connect

    Glicken, H.

    1985-01-01

    Large volcanic debris avalanches are among the world's largest mass movements. The rockslide-debris avalanche of the May 18, 1980, eruption of Mount St. Helens produced a 2.8 km/sup 3/ deposit and is the largest historic mass movement. A Pleistocene debris avalanche at Mount Shasta produced a 26 km/sup 3/ deposit that may be the largest Quaternary mass movement. The hummocky deposits at both volcanoes consist of rubble divided into (1) block facies that comprises unconsolidated pieces of the old edifice transported relatively intact, and (2) matrix facies that comprises a mixture of rocks from the old mountain and material picked up from the surrounding terrain. At Mount St. Helens, the juvenile dacite is found in the matrix facies, indicating that matrix facies formed from explosions of the erupting magma as well as from disaggregation and mixing of blocks. The block facies forms both hummocks and interhummock areas in the proximal part of the St. Helens avalanche deposit. At Mount St. Helens, the density of the old cone is 21% greater than the density of the avalanche deposit. Block size decreases with distance. Clast size, measured in the field and by sieving, coverages about a mean with distance, which suggests that blocks disaggregated and mixed together during transport.

  14. Lateral blasts at Mount St. Helens and hazard zonation

    USGS Publications Warehouse

    Crandell, D.R.; Hoblitt, R.P.

    1986-01-01

    Lateral blasts at andesitic and dacitic volcanoes can produce a variety of direct hazards, including ballistic projectiles which can be thrown to distances of at least 10 km and pyroclastic density flows which can travel at high speed to distances of more than 30 km. Indirect effect that may accompany such explosions include wind-borne ash, pyroclastic flows formed by the remobilization of rock debris thrown onto sloping ground, and lahars. Two lateral blasts occurred at a lava dome on the north flank of Mount St. Helens about 1200 years ago; the more energetic of these threw rock debris northeastward across a sector of about 30?? to a distance of at least 10 km. The ballistic debris fell onto an area estimated to be 50 km2, and wind-transported ash and lapilli derived from the lateral-blast cloud fell on an additional lobate area of at least 200 km2. In contrast, the vastly larger lateral blast of May 18, 1980, created a devastating pyroclastic density flow that covered a sector of as much as 180??, reached a maximum distance of 28 km, and within a few minutes directly affected an area of about 550 km2. The May 18 lateral blast resulted from the sudden, landslide-induced depressurization of a dacite cryptodome and the hydrothermal system that surrounded it within the volcano. We propose that lateral-blast hazard assessments for lava domes include an adjoining hazard zone with a radius of at least 10 km. Although a lateral blast can occur on any side of a dome, the sector directly affected by any one blast probably will be less than 180??. Nevertheless, a circular hazard zone centered on the dome is suggested because of the difficulty of predicting the direction of a lateral blast. For the purpose of long-term land-use planning, a hazard assessment for lateral blasts caused by explosions of magma bodies or pressurized hydrothermal systems within a symmetrical volcano could designate a circular potential hazard area with a radius of 35 km centered on the volcano

  15. Clast comminution during pyroclastic density current transport: Mt St Helens

    NASA Astrophysics Data System (ADS)

    Dawson, B.; Brand, B. D.; Dufek, J.

    2011-12-01

    Volcanic clasts within pyroclastic density currents (PDCs) tend to be more rounded than those in fall deposits. This rounding reflects degrees of comminution during transport, which produces an increase in fine-grained ash with distance from source (Manga, M., Patel, A., Dufek., J. 2011. Bull Volcanol 73: 321-333). The amount of ash produced due to comminution can potentially affect runout distance, deposit sorting, the volume of ash lofted into the upper atmosphere, and increase internal pore pressure (e.g., Wohletz, K., Sheridan, M. F., Brown, W.K. 1989. J Geophy Res, 94, 15703-15721). For example, increased pore pressure has been shown to produce longer runout distances than non-comminuted PDC flows (e.g., Dufek, J., and M. Manga, 2008. J. Geophy Res, 113). We build on the work of Manga et al., (2011) by completing a pumice abrasion study for two well-exposed flow units from the May 18th, 1980 eruption of Mt St Helens (MSH). To quantify differences in comminution from source, sampling and the image analysis technique developed in Manga et al., 2010 was completed at distances proximal, medial, and distal from source. Within the units observed, data was taken from the base, middle, and pumice lobes within the outcrops. Our study is unique in that in addition to quantifying the degree of pumice rounding with distance from source, we also determine the possible range of ash sizes produced during comminution by analyzing bubble wall thickness of the pumice through petrographic and SEM analysis. The proportion of this ash size is then measured relative to the grain size of larger ash with distance from source. This allows us to correlate ash production with degree of rounding with distance from source, and determine the fraction of the fine ash produced due to comminution versus vent-fragmentation mechanisms. In addition we test the error in 2D analysis by completing a 3D image analysis of selected pumice samples using a Camsizer. We find that the roundness of PDC

  16. Large-N Nodal Seismic Deployment at Mount St Helens

    NASA Astrophysics Data System (ADS)

    Hansen, S. M.; Schmandt, B.; Vidale, J. E.; Creager, K. C.; Levander, A.; Kiser, E.; Barklage, M.; Hollis, D.

    2014-12-01

    In late July of 2014 over 900 autonomous short period seismometers were deployed within 12 km of the summit crater at Mount St Helens. In concert with the larger iMUSH experiment, these data constitute the largest seismic interrogation of an active volcano ever conducted. The array was deployed along the road and trail system of the national volcanic monument and adjacent regions with an average station spacing of 250 meters and included several station clusters with increased sampling density. The 10 Hz phones recorded the vertical component wavefield continuously at 250 Hz sampling rate over a period of approximately two weeks. During the recording time, the Pacific Northwest Seismic Network detected ~65 earthquakes within the array footprint ranging in magnitude from -0.9 to 1.1, the majority of which were located beneath the crater at less than 10 km depth. In addition to the natural seismicity, 23 explosion sources from the iMUSH active source experiment were recorded, several of which exceeded magnitude 2. Preliminary results for this project will include an expanded event catalog as the array should significantly reduce the detection threshold. The sheer number of instruments allows for stacking of station clusters producing high signal-to-noise beam traces which can be used for event triggering and for creating waveform templates to measure relative travel-times across the array via cross-correlation. The ability of the array to estimate focal mechanisms from event radiation patterns and delineate complex path effects will also be investigated. The density and azimuthal coverage provide by this array offers an excellent opportunity to investigate short-wavelength variations of the seismic wavefield in a complex geologic environment. Previous seismic tomography results suggest the presence of a shallow magma chamber at 1-3 km depth near the region of shallow seismicity as evidenced by a P wave low-velocity anomaly of at least -5.5% [Waite and Moran, 2009

  17. Blast dynamics at Mount St Helens on 18 May 1980

    USGS Publications Warehouse

    Kieffer, S.W.

    1981-01-01

    At 8.32 a.m. on 18 May 1980, failure of the upper part of the north slope of Mount St Helens triggered a lateral eruption ('the blast') that devastated the conifer forests in a sector covering ???500 km2 north of the volcano. I present here a steady flow model for the blast dynamics and propose that through much of the devastated area the blast was a supersonic flow of a complex multiphase (solid, liquid, vapour) mixture. The shape of the blast zone; pressure, temperature, velocity (Mach number) and density distributions within the flow; positions of weak and strong internal shocks; and mass flux, energy flux, and total energy are calculated. The shape of blast zone was determined by the initial areal expansion from the reservoir, by internal expansion and compression waves (including shocks), and by the density of the expanding mixture. The pressure within the flow dropped rapidly away from the source of the blast until, at a distance of ???11 km, the flow became underpressured relative to the surrounding atmosphere. Weak shocks within the flow subparallel to the east and west margins coalesced at about this distance into a strong Mach disk shock, across which the flow velocities would have dropped from supersonic to subsonic as the pressure rose back towards ambient. The positions of the shocks may be reflected in differences in the patterns of felled trees. At the limits of the devastated area, the temperature had dropped only 20% from the reservoir temperature because the entrained solids thermally buffered the flow (the dynamic and thermodynamic effects of the admixture of the surrounding atmosphere and the uprooted forest and soils into the flow are not considered). The density of the flow decreased with distance until, at the limits of the blast zone, 20-25 km from the volcano, the density became comparable with that of the surrounding (dirty) atmosphere and the flow became buoyant and ramped up into the atmosphere. According to the model, the mass flux per

  18. Double-Difference Earthquake Locations Using imaging Magma Under St. Helens (iMUSH) Data

    NASA Astrophysics Data System (ADS)

    Williams, M. C. B.; Ulberg, C. W.; Creager, K. C.

    2015-12-01

    The imaging Magma Under St. Helens (iMUSH) project deployed a magnetotelluric survey, high-resolution active-source experiment, two-year passive-source experiment, and gathered geochemical-petrological data to better understand the magmatic architecture of Mount St. Helens. A primary goal of the passive source experiment is to create 3-D P-wave and S-wave velocity models under the volcano from the surface to the slab. We use hypoDD, a double-difference algorithm, to gain high-precision relative earthquake locations for several hundred events within tens of kilometers of the Mount St. Helens crater. We use data from the first half (2014 June- 2015 July) of the two-year passive-source component of the iMUSH array recording six hundred useable earthquakes with a high-event density near the volcanic crater. The array includes seventy evenly-spaced broadband seismometers continuously sampling at 50 Hz within a 50 km radius of Mount St. Helens, and is augmented by dozens of permanent network stations. Precise relative earthquake locations are determined for spatially clustered hypocenters using a combination of hand picked P-wave arrivals and high-precision relative times determined by cross correlation of waveforms recorded at a common station for event pairs using a 1-D velocity structure. These high-quality relative times will be used to help constrain seismic tomography models as well. We will interrupt earthquake clusters in the context of emerging 3-D wave-speed models from the active-source and passive-source observations. We are examining the relationship between hypocentral locations and regions of partial melt, as well as the relationship between hypocentral locations and the NNW-SSE trending Saint Helens seismic Zone.

  19. A Gentle Frost: Poet Helen Frost Talks about the Healing Power of Poetry and Her Latest Novel

    ERIC Educational Resources Information Center

    Margolis, Rick

    2006-01-01

    This article presents an interview with poet Helen Frost. Frost talked about how poetry can help at-risk children. She also related the challenges she faced when she wrote her latest book titled "The Braid."

  20. Mount St. Helens erupts again: activity from September 2004 through March 2005

    USGS Publications Warehouse

    Major, Jon J.; Scott, William E.; Driedger, Carolyn; Dzurisin, Dan

    2005-01-01

    Eruptive activity at Mount St. Helens captured the world’s attention in 1980 when the largest historical landslide on Earth and a powerful explosion reshaped the volcano, created its distinctive crater, and dramatically modified the surrounding landscape. Over the next 6 years, episodic extrusions of lava built a large dome in the crater. From 1987 to 2004, Mount St. Helens returned to a period of relative quiet, interrupted by occasional, short-lived seismic swarms that lasted minutes to days, by months-to-yearslong increases in background seismicity that probably reflected replenishment of magma deep underground, and by minor steam explosions as late as 1991. During this period a new glacier grew in the crater and wrapped around and partly buried the lava dome. Although the volcano was relatively quiet, scientists with the U.S. Geological Survey and University of Washington’s Pacific Northwest Seismograph Network continued to closely monitor it for signs of renewed activity.

  1. Processing and interpretation of microbarograph signals generated by the explosion of Mount St. Helens

    SciTech Connect

    Delclos, C.; Blanc, E. ); Broche, P. ); Glangeaud, F.; Lacoume, J.L. )

    1990-04-20

    Following the eruption of the Mount St. Helens volcano on May 18, 1980, atmospheric waves were recorded by a network of micrographs located over 7,000 km from the source. Analysis of these data requires the use of complex processing techniques based on a high-resolution method to extract the signals produced by the St. Helens source from spurious waves or noise in each record. This facilitates interpretation of the wave trains in terms of propagation modes. It is thus shown that Lamb mode L{sub 0} is present in the low-frequency part of all signals, whereas acoustic modes (more probably A{prime}{sub 2}) are needed to explain all the properties of the high-frequency part, which is clearly observed for a westward and a southward propagation.

  2. Geologic Map of Mount St. Helens, Washington Prior to the 1980 Eruption

    USGS Publications Warehouse

    Hopson, Clifford A.

    2008-01-01

    It is rare that a geologic map exists for a volcano prior to such a catastrophic modification as that produced by the eruption of Mount St. Helens in 1980. As such, this map provides an important historical record of the volcano prior to that eruption. The map has not been reviewed or checked for conformity to USGS editorial standards or stratigraphic nomenclature, and it has not been digitized. This version of the map is unchanged from that submitted to the USGS for publication shortly after the 1980 eruption of Mount St. Helens and includes unresolved inconsistencies with the subsequently published work of Crandell (1987) and Mullineaux (1996). Nevertheless, it is the most accurate available depiction of the pre-1980 edifice and is published here for comparison with more recent geologic mapping and historical perspectives.

  3. Monitoring vegetation recovery patterns on Mount St. Helens using thermal infrared multispectral data

    NASA Technical Reports Server (NTRS)

    Langran, Kenneth J.

    1986-01-01

    The Mount St. Helens 1980 eruption offers an opportunity to study vegetation recovery rates and patterns in a perturbed ecosystem. The eruptions of Mount St. Helens created new surfaces by stripping and implacing large volumes of eroded material and depositing tephra in the blast area and on the flanks of the mountain. Areas of major disturbance are those in the blast zone that were subject to debris avalanche, pyroclastic flows, mudflows, and blowdown and scorched timber; and those outside the blast zone that received extensive tephra deposits. It was observed that during maximum daytime solar heating, surface temperatures of vegetated areas are cooler than surrounding nonvegetated areas, and that surface temperature varies with percent vegetation cover. A method of measuring the relationship between effective radiant temperature (ERT) and percent vegetation cover in the thermal infrared (8 to 12 microns) region of the electromagnetic spectrum was investigated.

  4. VLF electromagnetic investigations of the crater and central dome of Mount St. Helens, Washington

    USGS Publications Warehouse

    Towle, J.N.

    1983-01-01

    A very low frequency (VLF) electromagnetic induction survey in the crater of Mount St. Helens has identified several electrically conductive structures that appear to be associated with thermal anomalies and ground water within the crater. The most interesting of these conductive structures lies beneath the central dome. It is probably a partial melt of dacite similar to that comprising the June 1981 lobe of the central dome. ?? 1983.

  5. Eruption-triggered avalanche, flood, and lahar at Mount St. Helens - Effects of winter snowpack

    USGS Publications Warehouse

    Waitt, R.B., Jr.; Pierson, T.C.; MacLeod, N.S.; Janda, R.J.; Voight, B.; Holcomb, R.T.

    1983-01-01

    An explosive eruption of Mount St. Helens on 19 March 1982 had substantial impact beyond the vent because hot eruption products interacted with a thick snowpack. A blast of hot pumice, dome rocks, and gas dislodged crater-wall snow that avalanched through the crater and down the north flank. Snow in the crater swiftly melted to form a transient lake, from which a destructive flood and lahar swept down the north flank and the North Fork Toutle River.

  6. Temporal change in coda wave attenuation observed during an eruption of Mount St. Helens

    SciTech Connect

    Fehler, M.; Roberts, P.; Fairbanks, T.

    1988-05-10

    During the past few years there have been numerous reports of changes in coda wave attenuation occurring before major earthquakes. These observations are important because they may provide insight into stress-related structural changes taking place in the focal region prior to the occurrence of large earthquakes. The results of these studies led us to suspect that temporal changes in coda wave attenuation might also accompany volcanic eruptions. By measuring power decay envelopes for earthquakes at Mount St. Helens recorded before, during, and after an eruption that took place during September 3--6, 1981, we found that coda Q/sup -1/ for frequencies between 6 and 30 Hz was 20--30% higher before the eruption than after. The change is attributed to an increase in the density of open microcracks in the rock associated with inflation of the volcano prior to the eruption. Q/sup -1/ was found to be only weakly dependent on frequency and displayed a slight peak near 10 Hz. The weak frequency dependence is attributed to the dominance of intrinsic attenuation over scattering attenuation, since it is generally accepted that intrinsic attenuation is constant with frequency, whereas scattering attenuation decreases strongly at higher frequencies. The weak frequency dependence of Q/sup -1/ at Mount St. Helens contrasts with results reported for studies in nonvolcanic regions. The peak in Q/sup -1/ near 10 Hz at Mount St. Helens is attributed to the scale length of heterogeneity responsible for generating backscattered waves. Results for nonvolcanic regions have shown this peak to occur near 0.5 Hz. Thus a smaller scale length of heterogeneity is required to explain the 10-Hz peak at Mount St. Helens. copyright American Geophysical Union 1988

  7. Trace element composition of the Mount St. Helens plume: stratospheric samples from the 18 May eruption

    SciTech Connect

    Vossler, T.; Anderson, D.L.; Aras, N.K.; Phelan, J.M.; Zoller, W.H.

    1981-01-01

    Atmospheric particulate material collected from the stratosphere in plume of the 18 May 1980 eruption of the Mount St. Helens volcano was quite similar in composition to that of ash that fell to the ground in western Washington. However, there were small but significant differences in concentrations of some elements with altitude, indicating that the statospheric material was primarily produced from fresh magma, but fragments of the mountain.

  8. The Evolution and Role of the Saharan Air Layer During Hurricane Helene (2006)

    NASA Technical Reports Server (NTRS)

    Braun, Scott A.; Sippel, Jason A.; Shie, Chung-Lin; Boller, Ryan A.

    2013-01-01

    The Saharan air layer (SAL) has received considerable attention in recent years as a potential negative influence on the formation and development of Atlantic tropical cyclones. Observations of substantial Saharan dust in the near environment of Hurricane Helene (2006) during the National Aeronautics and Space Administration (NASA) African Monsoon Multidisciplinary Activities (AMMA) Experiment (NAMMA) field campaign led to suggestions about the suppressing influence of the SAL in this case. In this study, a suite of satellite remote sensing data, global meteorological analyses, and airborne data are used to characterize the evolution of the SAL in the environment of Helene and assess its possible impact on the intensity of the storm. The influence of the SAL on Helene appears to be limited to the earliest stages of development, although the magnitude of that impact is difficult to determine observationally. Saharan dust was observed on the periphery of the storm during the first two days of development after genesis when intensification was slow. Much of the dust was observed to move well westward of the storm thereafter, with little SAL air present during the remainder of the storm's lifetime and with the storm gradually becoming a category-3 strength storm four days later. Dry air observed to wrap around the periphery of Helene was diagnosed to be primarily non-Saharan in origin (the result of subsidence) and appeared to have little impact on storm intensity. The eventual weakening of the storm is suggested to result from an eyewall replacement cycle and substantial reduction of the sea surface temperatures beneath the hurricane as its forward motion decreased.

  9. Size distributions and mineralogy of ash particles in the stratosphere from eruptions of mount st. Helens.

    PubMed

    Farlow, N H; Oberbeck, V R; Snetsinger, K G; Ferry, G V; Polkowski, G; Hayes, D M

    1981-02-20

    Samples from the stratosphere obtained by U-2 aircraft after the first three major eruptions of Mount St. Helens contained large globules of liquid acid and ash. Because of their large size, these globules had disappeared from the lower stratosphere by late June 1980, leaving behind only smaller acid droplets. Particle-size distributions and mineralogy of the stratospheric ash grains demonstrate in-homogeneity in the eruption clouds.

  10. Multi-scale roughness spectra of Mount St. Helens debris flows

    NASA Technical Reports Server (NTRS)

    Austin, Richard T.; England, Anthony W.

    1993-01-01

    A roughness spectrum allows surface structure to be interpreted as a sum of sinusoidal components with differing wavelengths. Knowledge of the roughness spectrum gives insight into the mechanisms responsible for electromagnetic scattering at a given wavelength. Measured spectra from 10-year-old primary debris flow surfaces at Mount St. Helens conform to a power-law spectral model, suggesting that these surfaces are scaling over the measured range of spatial frequencies. Measured spectra from water-deposited surfaces deviate from this model.

  11. Preliminary Shear Velocity Tomography of Mt St Helens, Washington from iMUSH Array

    NASA Astrophysics Data System (ADS)

    Crosbie, K.; Abers, G. A.; Creager, K. C.; Moran, S. C.; Denlinger, R. P.; Ulberg, C. W.

    2015-12-01

    The imaging Magma Under Mount St Helens (iMUSH) experiment will illuminate the crust beneath Mt St Helens volcano. The ambient noise tomography (ANT) component of this experiment measures shear velocity structure, which is more sensitive than P velocity to the presence of melt and other pore fluids. Seventy passive-source broadband seismometers for iMUSH were deployed in the summer of 2014 in a dense array of 100 Km diameter with a 10 km station spacing. We cross correlated ambient noise in 120 s windows and summed the result over many months for pairs of stations. Then frequency-domain methods on these cross correlations are employed to measure the phase velocities (Ekström et al. Geophys Rev Lett, 2009). Unlike velocities attained by group velocity methods, velocities for path lengths as small as one wavelength can be measured, enabling analysis of higher frequency signals and increasing spatial resolution. The minimum station spacing from which signals can be recovered ranges from 12 km at 0.18 Hz, a frequency that dominantly samples the upper crust to 20 km, to 37 km at 0.04 Hz, a frequency sensitive to structure through the crust and uppermost mantle, with lower spacing at higher frequencies. These phase velocities are tomographically inverted to obtain shear velocity maps for each frequency, assuming ray theory. Initial shear velocity maps for frequencies between 0.04-0.18 Hz reveal low-velocity sediments in the Puget Lowland west of Mount St Helens at 0.16-0.18 Hz, and a low velocity zone near 0.10 Hz between Mt Rainier and Mt Adams, east of Mount St Helens. The latter may reflect large-scale crustal plumbing of the arc between volcanic centers. In subsequent analyses these ANT results will be jointly inverted with receiver functions in order to further resolve crustal and upper mantle structure.

  12. Impact of Mount St. Helens eruption on hydrology and water quality

    NASA Technical Reports Server (NTRS)

    Bonelli, J. E.; Taylor, H. E.; Klein, J. M.

    1982-01-01

    The 1980 eruptions of Mount St. Helens in southeast Washington resulted in a pronounced effect on the surface and ground water resources of the state. In response to the volcanic activity, the U.S. Geological Survey intensified statewide surface and ground water sampling programs to determine the nature and magnitude of the volcanic-induced variations. Streams to the east of Mount St. Helens received the major ash fallout. Chemical effects were best noted in smaller streams sampled 60 to 70 miles northeast of Mount St. Helens. The chemical variations observed were pronounced but short lived. Sulfate and chloride increases in anionic composition were prevalent immediately following the eruption; however, the original bicarbonate predominance was again attained within several days. Suspended iron and aluminum concentrations were similarly elevated during the period of greatest ash deposition (highest turbidity); however, the dissolved concentrations remained relatively constant. Depressions of pH were minor and short lived. Streams draining to the south, tributaries to the Columbia river, showed little observable changes in water chemistry. Streams draining to the west (Toutle river and its tributaries) were compositionally affected by the various volcanic activities. Chloride and sulfate anion percentage exceeded the bicarbonate percentage up to one month following the eruption period. Streams and lakes sampled in the immediate vicinity of Mount St. Helens, in addition to trace metals, contained organic compounds derived from decomposing wood buried in the debris deposits. This organic material may constitute a significant source of organic compounds to surface and ground water for some time to come.

  13. A decade of dome growth at Mount St. Helens, 1980-90

    USGS Publications Warehouse

    Swanson, D.A.

    1990-01-01

    The growth of the dacite dome at Mount St. Helens between 1980 and 1986 has been more intensively studied than that of any other dome-building eruption. The growth has been complex in detail, but remarkably regular overall. This paper summarizes some of what has been learned and provides many references to additional information. Whether dome building has ended is an open question, particularly in view of the renewed, though minor, explosive activity of late 1989 and early 1990. -Author

  14. Holocene geomagnetic secular variation recorded by volcanic deposits at Mount St. Helens, Washington

    USGS Publications Warehouse

    Hagstrum, J.T.; Hoblitt, R.P.; Gardner, C.A.; Gray, T.E.

    2002-01-01

    A compilation of paleomagnetic data from volcanic deposits of Mount St. Helens is presented in this report. The database is used to determine signature paleomagnetic directions of products from its Holocene eruptive events, to assign sampled units to their proper eruptive period, and to begin the assembly of a much larger database of paleomagnetic directions from Holocene volcanic rocks in western North America. The paleomagnetic results from Mount St. Helens are mostly of high quality, and generally agree with the division of its volcanic deposits into eruptive episodes based on previous geologic mapping and radiocarbon dates. The Muddy River andesite's paleomagnetic direction, however, indicates that it is more likely part of the Pine Creek eruptive period rather than the Castle Creek period. In addition, the Two-Fingers andesite flow is more likely part of the Middle Kalama eruptive period and not part of the Goat Rocks period. The paleomagnetic data from Mount St. Helens and Mount Hood document variation in the geomagnetic field's pole position over the last ~2,500 years. A distinct feature of the new paleosecular variation (PSV) record, similar to the Fish Lake record (Oregon), indicates a sudden change from rapid clockwise movement of the pole about the Earth's spin axis to relatively slow counterclockwise movement at ???800 to 900 years B.P.

  15. A new tree-ring date for the "floating island" lava flow, Mount St. Helens, Washington

    USGS Publications Warehouse

    Yamaguchi, D.K.; Hoblitt, R.P.; Lawrence, D.B.

    1990-01-01

    Anomalously narrow and missing rings in trees 12 m from Mount St. Helens' "floating island" lava flow, and synchronous growth increases in trees farther from the flow margin, are evidence that this andesitic flow was extruded between late summer 1799 and spring 1800 a.d., within a few months after the eruption of Mount St. Helens' dacitic layer T tephra. For ease of reference, we assign here an 1800 a.d. date to this flow. The new date shows that the start of Mount St. Helens' Goat Rocks eruptive period (1800-1857 a.d.) resembled the recent (1980-1986) activity in both petrochemical trends and timing. In both cases, an initial explosive eruption of dacite was quickly succeeded by the eruption of more mafic lavas; dacite lavas then reappeared during an extended concluding phase of activity. This behavior is consistent with a recently proposed fluid-dynamic model of magma withdrawal from a compositionally zoned magma chamber. ?? 1990 Springer-Verlag.

  16. Deposition and dose from the 18 May 1980 eruption of Mount St. Helens

    NASA Technical Reports Server (NTRS)

    Peterson, K. R.

    1982-01-01

    The downwind deposition and radiation doses was calculated for the tropospheric part of the ash cloud from the May 18, 1980 eruption of Mount St. Helens, by using a large cloud diffusion model. The naturally occurring radionnuclides of radium and thorium, whose radon daughters normally seep very slowly from the rocks and soil, were violently released to the atmosphere. The largest dose to an individual from these nuclides is small, but the population dose to those affected by the radioactivity in the ash is about 100 person rem. This population dose from Mount St. Helens is much greater than the annual person rem routinely released by a typical large nuclear power plant. It is estimated that subsequent eruptions of Mount St. Helens have doubled or tripled the person rem calculated from the initial large eruption. The long range global ash deposition of the May 18 eruption is estimated through 1984, by use of a global deposition model. The maximum deposition is nearly 1000 kg square km and occurs in the spring of 1981 over middle latitudes of the Northern Hemisphere.

  17. Forecasts and predictions of eruptive activity at Mount St. Helens, USA: 1975-1984

    USGS Publications Warehouse

    Swanson, D.A.; Casadevall, T.J.; Dzurisin, D.; Holcomb, R.T.; Newhall, C.G.; Malone, S.D.; Weaver, C.S.

    1985-01-01

    Public statements about volcanic activity at Mount St. Helens include factual statements, forecasts, and predictions. A factual statement describes current conditions but does not anticipate future events. A forecast is a comparatively imprecise statement of the time, place, and nature of expected activity. A prediction is a comparatively precise statement of the time, place, and ideally, the nature and size of impending activity. A prediction usually covers a shorter time period than a forecast and is generally based dominantly on interpretations and measurements of ongoing processes and secondarily on a projection of past history. The three types of statements grade from one to another, and distinctions are sometimes arbitrary. Forecasts and predictions at Mount St. Helens became increasingly precise from 1975 to 1982. Stratigraphic studies led to a long-range forecast in 1975 of renewed eruptive activity at Mount St. Helens, possibly before the end of the century. On the basis of seismic, geodetic and geologic data, general forecasts for a landslide and eruption were issued in April 1980, before the catastrophic blast and landslide on 18 May 1980. All extrusions except two from June 1980 to the end of 1984 were predicted on the basis of integrated geophysical, geochemical, and geologic monitoring. The two extrusions that were not predicted were preceded by explosions that removed a substantial part of the dome, reducing confining pressure and essentially short-circuiting the normal precursors. ?? 1985.

  18. Eruptive activity at Mount St Helens, Washington, USA, 1984-1988: a gas geochemistry perspective

    USGS Publications Warehouse

    McGee, K.A.; Sutton, A.J.

    1994-01-01

    The results from two different types of gas measurement, telemetered in situ monitoring of reducing gases on the dome and airborne measurements of sulfur dioxide emission rates in the plume by correlation spectrometry, suggest that the combination of these two methods is particularly effective in detecting periods of enhanced degassing that intermittently punctuate the normal background leakage of gaseous effluent from Mount St Helens to the atmosphere. Gas events were recorded before lava extrusion for each of the four dome-building episodes at Mount St Helens since mid-1984. For two of the episodes, precursory reducing gas peaks were detected, whereas during three of the episodes, COSPEC measurements recorded precursory degassing of sulfur dioxide. During one episode (October 1986), both reducing gas monitoring and SO2 emission rate measurements simultaneously detected a large gas release several hours before lava extrusion. Had both types of gas measurements been operational during each of the dome-building episodes, it is thought that both would have recorded precursory signals for all four episodes. Evidence from the data presented herein suggests that increased degassing at Mount St Helens becomes detectable when fresh upward-moving magma is between 2 km and a few hundred meters below the base of the dome and between about 60 and 12 hours before the surface extrusion of lava. ?? 1994 Springer-Verlag.

  19. Mount St. Helens, 1980 to now—what’s going on?

    USGS Publications Warehouse

    Dzurisin, Daniel; Driedger, Carolyn L.; Faust, Lisa M.

    2013-01-01

    Mount St. Helens seized the world’s attention in 1980 when the largest historical landslide on Earth and a powerful explosive eruption reshaped the volcano, created its distinctive crater, and dramatically modified the surrounding landscape. An enormous lava dome grew episodically in the crater until 1986, when the volcano became relatively quiet. A new glacier grew in the crater, wrapping around and partly burying the lava dome. From 1987 to 2003, sporadic earthquake swarms and small steam explosions indicated that magma (molten rock) was being replenished deep underground. In 2004, steam-and-ash explosions heralded the start of another eruption. A quieter phase of continuous lava extrusion followed and lasted until 2008, building a new dome and doubling the volume of lava on the crater floor. Scientists with the U.S. Geological Survey and University of Washington’s Pacific Northwest Seismograph Network maintain constant watch for signs of renewed activity at Mount St. Helens and other Cascade volcanoes. Now is an ideal time for both actual and virtual visitors to Mount St. Helens to learn more about dramatic changes taking place on and beneath this active volcano.

  20. Mount St. Helens: A case study of managing for change in wildland recreation

    NASA Astrophysics Data System (ADS)

    Ewert, Alan

    1990-03-01

    Mount St. Helens provides an interesting case study of a forest and wildland area that has been radically altered in recent history. As a result of volcanic activity, the recreation environment has changed with respect to the setting, climbing opportunities, and motivations for mountaineering. An evaluation process using both qualitative and quantitative methods was developed to determine what the motivations, demographic characteristics, and preferred management techniques were for the posteruption Mount St. Helens mountain-climbing visitor. Results suggest that changes have occurred in the “new” or posteruption climbing visitor. These changes have not all been congruent with those anticipated by management. For example, the climbing visitor is now less interested in climbing opportunities and more concerned with seeing the crater and other volcanic-related features. This article discusses the findings of this research in light of how resource managers might consider the issue of visitor changes in both demands and types of uses. For example, determining quota numbers based on sociological determinants (e.g., desire for solitude) need to be firmly grounded in who the visitors actually are rather than who they were. Consequently, management tools such as the Recreational Opportunity Spectrum (ROS) and Limits of Acceptable Change (LAC) may need to be altered to accommodate a changing resource or visitor base. These and other findings have implications for the future management practices of the Mount St. Helens area and other environments where the recreation resources have undergone rapid and profound change.

  1. Proximal ecological effects of the 1980 eruptions of Mount St. Helens

    NASA Technical Reports Server (NTRS)

    Swanson, F. J.

    1988-01-01

    The diversity of ecosystems and volcanic processes involved in the 1980 eruptions of Mount St. Helens, southwest Washington, provide an excellent setting for examining effects of volcanic events on ecosystems. These eruptions included a lateral blast, debris avalanche, mudflows, pyroclastic flows, and airfall tephra. Affected ecosystems within 30 km of the vent were lakes, streams, upland and riparian forest, and meadows. Ecological disturbances imposed by the Mount St. Helens events were predominantly physical, rather than climatic or chemical which are the dominant classes of disturbances considered in analysis of global catastrophes. Analysis of ecosystem response to disturbance should be based on consideration of composition and structure of the predisturbance system in terms that represent potential survivability of organisms, mechanisms in the primary disturbance, initial survivors, secondary disturbances arising from the primary disturbance and the biological responses to secondary disturbances, invasion of the site by new propagules, interactions among secondary disturbance processes and surviving and invading organisms. Predicting ecosystem response to disturbance is enchanced by considering the mechanisms of disturbance rather than type of disturbance. In the 1980 Mount St. Helens events, the disturbance types, involved primarily the mechanisms of sedimentation, heating, and shear stress. Each disturbance type involved one or more mechanisms. Ecosystem response varied greatly across the landscape. Analysis of ecosystem response to disturbance, regardless of type, should include detailed consideration of the properties of individual species, primary and secondary disturbance mechanisms, and their distributions across landscapes.

  2. Distribution of melt beneath Mount St Helens and Mount Adams inferred from magnetotelluric data

    USGS Publications Warehouse

    Hill, G.J.; Caldwell, T.G.; Heise, W.; Chertkoff, D.G.; Bibby, H.M.; Burgess, M.K.; Cull, J.P.; Cas, Ray A.F.

    2009-01-01

    Three prominent volcanoes that form part of the Cascade mountain range in Washington State (USA)Mounts StHelens, Adams and Rainierare located on the margins of a mid-crustal zone of high electrical conductivity1,5. Interconnected melt can increase the bulk conductivity of the region containing the melt6,7, which leads us to propose that the anomalous conductivity in this region is due to partial melt associated with the volcanism. Here we test this hypothesis by using magnetotelluric data recorded at a network of 85 locations in the area of the high-conductivity anomaly. Our data reveal that a localized zone of high conductivity beneath thisvolcano extends downwards to join the mid-crustal conductor. As our measurements were made during the recent period of lava extrusion at Mount St Helens, we infer that the conductivity anomaly associated with the localized zone, and by extension with the mid-crustal conductor, is caused by the presence of partial melt. Our interpretation is consistent with the crustal origin of silicic magmas erupting from Mount St Helens8, and explains the distribution of seismicity observed at the time of the catastrophic eruption in 1980 (refs9, 10). ?? 2009 Macmillan Publishers Limited. All rights reserved.

  3. The dust environment surrounding the E-ring moons Dione, Helene and Polydeuce

    NASA Astrophysics Data System (ADS)

    Moldenhawer, T.; Hoffmann, H.; Seiß, M.; Sachse, M.; Spahn, F.

    2015-10-01

    Compared to the dust clouds around three of the Galilean satellites of Jupiter, no clear Saturnian pendants have been found yet by the CDA detector aboardthe Cassini spacecraft. However, three dust tori and arcs have been detected along the orbits of Pallene, Methone and Anthe in ISS images [1] and the Pallene dust torus was confirmed by in situ CDA measurements [4]. These observations have sparked interest whether the small co-orbital companions to E-ring moons like Dione or Thetys are efficient dust sources. We simulate the motion of dust particles, which originate from hypervelocity impacts of micrometeoroids onto Dione, Helene and Polydeuce [2]. Gravity, Lorentz force, solar radiation pressure and plasma drag are considered for the dynamic evolution of small dust particles. Assuming a steady state distribution, we scale the phase space data with dust production rates based on recent IDP measurements at Saturn [3]. We will present dust particle number densities along the orbits of Dione, Helene and Polydeuce and we will make predictions for the Cassini flybys of Helene and Polydeuce, which take place in the summer and fall this year.

  4. Catalog of Mount St. Helens 2004 - 2005 Tephra Samples with Major- and Trace-Element Geochemistry

    USGS Publications Warehouse

    Rowe, Michael C.; Thornber, Carl R.; Gooding, Daniel J.; Pallister, John S.

    2008-01-01

    This open-file report presents a catalog of information about 135 ash samples along with geochemical analyses of bulk ash, glass and individual mineral grains from tephra deposited as a result of volcanic activity at Mount St. Helens, Washington, from October 1, 2004 until August 15, 2005. This data, in conjunction with that in a companion report on 2004?2007 Mount St. Helens dome samples by Thornber and others (2008a) are presented in support of the contents of the U.S. Geological Survey Professional Paper 1750 (Sherrod and others, ed., 2008). Readers are referred to appropriate chapters in USGS Professional Paper 1750 for detailed narratives of eruptive activity during this time period and for interpretations of sample characteristics and geochemical data presented here. All ash samples reported herein are currently archived at the David A. Johnston Cascades Volcano Observatory in Vancouver, Washington. The Mount St. Helens 2004?2005 Tephra Sample Catalogue along with bulk, glass and mineral geochemistry are tabulated in 6 worksheets of the accompanying Microsoft Excel file, of2008-1131.xls. Samples in all tables are organized by collection date. Table 1 is a detailed catalog of sample information for tephra deposited downwind of Mount St. Helens between October 1, 2004 and August 18, 2005. Table 2 provides major- and trace-element analyses of 8 bulk tephra samples collected throughout that interval. Major-element compositions of 82 groundmass glass fragments, 420 feldspar grains, and 213 mafic (clinopyroxene, amphibole, hypersthene, and olivine) mineral grains from 12 ash samples collected between October 1, 2004 and March 8, 2005 are presented in tables 3 through 5. In addition, trace-element abundances of 198 feldspars from 11 ash samples (same samples as major-element analyses) are provided in table 6. Additional mineral and bulk ash analyses from 2004 and 2005 ash samples are published in chapters 30 (oxide thermometry; Pallister and others, 2008), 32

  5. Effects of the 1980 eruption of Mount St Helens on the limnological characteristics of selected lakes in western Washington

    USGS Publications Warehouse

    Embrey, S.S.; Dion, N.P.

    1988-01-01

    The 1980 eruption of Mount St. Helens provided the opportunity to study its effect on the physical, chemical, and biological characteristics of lakes near the volcano, and to describe two newly created lakes. Concentrations of dissolved solids and organic carbon, measured in June 1980, had increased from 2 to 30 times those observed in the 1970 's in Spirit, St. Helens, and Venus Lakes. Water in the lakes was altered from preeruption calcium-bicarbonate types to calcium-sulfate, calcium sulfate-chloride, or lake surface, as in St. Helens Lake; transparency in Venus Lake had improved to a depth of 24 ft by 1982. Spirit Lake was anoxic into fall 1980, but had reaerated to 5.2 mg/L of dissolved oxygen by May 1981. Phytoplankton communities in existing lakes in the blast zone in 1980 were primarily green and bluegreen algae; diatoms were sparse until summer 1982. Small numbers of zooplankton in Spirit, St. Helens, and Venus Lakes, compared to numbers in Walupt and Fawn Lakes, may indicate some post-eruption mortality. Rotifers were absent from lakes in the blast zone, but by 1981 were observed in all the lakes. The recovery of the physical, chemical, and biological characteristics of the lakes will depend on stabilization of the surrounding environment and biological processes within each lake. Excluding Spirit Lake, it is estimated that St. Helens Lake would be the slowest to recover and Venus Lake the fastest. (USGS)

  6. Frictional properties of the Mount St. Helens gouge: Chapter 20 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

    USGS Publications Warehouse

    Moore, Peter L.; Iverson, Neal R.; Iverson, Richard M.; Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

    2008-01-01

    Rate-weakening friction is a requirement for stick-slip behavior that is satisfied by the Mount St. Helens gouge. Indeed, regular stick-slip oscillations were observed in two experiments performed at the highest normal stress and lowest rates of shear. The conditions under which this stick-slip motion occurred indicate that the gouge also satisfies a second criterion for stick-slip behavior of materials exhibiting rateand-state dependent friction-gouge stiffness exceeds that of the ascending magma that drives upward motion of the plug. The presence of highly compliant magma as a driving element may be crucial for generating stick-slip instabilities at the shallow earthquake focal depths observed during the eruption.

  7. Lidar observations of the Mount St. Helens eruption clouds over mid-Europe, May to July 1980

    NASA Astrophysics Data System (ADS)

    Reiter, R.; Jaeger, H.; Carnuth, W.; Funk, W.

    1980-12-01

    Three violent eruptions of the Mount St. Helens volcano on 18 and 24 May and 13 June terminated the period of background aerosol prevailing in the stratosphere since the end of 1976, after the decay of the volcanic aerosols injected by the Fuego eruption in 1974. The Mt. St. Helens eruption cloud arrived over mid-Europe on 26 May. The subsequent formation of a multi-layered aerosol structure between 12 and 24 km could be observed by the ground-based lidar at Garmisch-Partenkirchen. The highest altitude of 24 km was reached on 30 June, the maximum scattering ratio of 4.8 at 21 km on 14 July. The scattering ratios observed indicate that the St. Helens eruption is comparable to that of Fuego in 1974.

  8. VP Structure of Mount St. Helens, Washington, USA, imaged with local earthquake tomography

    USGS Publications Warehouse

    Waite, G.P.; Moran, S.C.

    2009-01-01

    We present a new P-wave velocity model for Mount St. Helens using local earthquake data recorded by the Pacific Northwest Seismograph Stations and Cascades Volcano Observatory since the 18 May 1980 eruption. These data were augmented with records from a dense array of 19 temporary stations deployed during the second half of 2005. Because the distribution of earthquakes in the study area is concentrated beneath the volcano and within two nearly linear trends, we used a graded inversion scheme to compute a coarse-grid model that focused on the regional structure, followed by a fine-grid inversion to improve spatial resolution directly beneath the volcanic edifice. The coarse-grid model results are largely consistent with earlier geophysical studies of the area; we find high-velocity anomalies NW and NE of the edifice that correspond with igneous intrusions and a prominent low-velocity zone NNW of the edifice that corresponds with the linear zone of high seismicity known as the St. Helens Seismic Zone. This low-velocity zone may continue past Mount St. Helens to the south at depths below 5??km. Directly beneath the edifice, the fine-grid model images a low-velocity zone between about 2 and 3.5??km below sea level that may correspond to a shallow magma storage zone. And although the model resolution is poor below about 6??km, we found low velocities that correspond with the aseismic zone between about 5.5 and 8??km that has previously been modeled as the location of a large magma storage volume. ?? 2009 Elsevier B.V.

  9. Characterization of organic contaminants in environmental samples associated with mount St. Helens 1980 volcanic eruption

    USGS Publications Warehouse

    Pereira, W.E.

    1982-01-01

    Volcanic ash, surface-water, and bottom-material samples obtained in the vicinity of Mount St. Helens after the May 18, 1980, eruption were analyzed for organic contaminants by using capillary gas chromatography-mass spectrometry-computer techniques. Classes of compounds identified include n-alkanes, fatty acids, dicarboxylic acids, aromatic acids and aldehydes, phenols, resin acids, terpenes, and insect juvenile hormones. The most probable source of these compounds is from pyrolysis of plant and soil organic matter during and after the eruption. The toxicity of selected compounds and their environmental significance are discussed.

  10. Evaluation of radon progeny from Mount St. Helens eruptions. Final report

    SciTech Connect

    Lepel, E.A.; Olsen, K.B.; Thomas, V.W.; Eichner, F.N.

    1982-09-01

    A network of twelve monitoring sites around Mount St. Helens was established to evaluate possible short-lived radioactivity in the fallen ash. Seven sites were located near major population centers of Washington and Oregon, and five sites were located within 80 km of the volcano. Each site monitored the radioactivity present by the use of thermoluminescent dosimeters which recorded the total exposure to radioactivity over the exposure period. Eruptions occurring on July 22, August 7, and October 16 to 18, 1980 were monitored. No statistically significant quantities of measurable radon daughters were observed.

  11. Direct temperature measurements of deposits, Mount St. Helens, Washington, 1980-1981

    USGS Publications Warehouse

    Banks, N.G.; Hoblitt, R.P.

    1996-01-01

    A program of temperature studies of the eruptive products of Mount St. Helens was established May 20, 1980, just 2 days after the catastrophic eruption of May 18. In general, the more recent deposits were emplaced at higher temperatures than the earlier ones. Emplacement temperatures of deposits of the debris avalanche of May 18 ranged from about 70 to 100 deg C, of the directed blast of May 18 from about 100 to 325 deg C (depending on azimuth from the vent), and of the subsequent pumiceous pyroclastic flows from about 300 to 850 deg C. Temperatures of the summit domes were as high as 897 deg C.

  12. Airborne studies of the emissions from the volcanic eruptions of mount st. Helens.

    PubMed

    Hobbs, P V; Radke, L F; Eltgroth, M W; Hegg, D A

    1981-02-20

    The concentrations of particles less than 10 micrometers in diameter in the ash emissions from Mount St. Helens have been more than 1000 times greater than those in the ambient air. Mass loadings of particles less than 2 micrometers in diameter were generally several hundred micrograms per cubic meter. In the ash clouds, produced by the large eruption on 18 May 1980, the concentrations of several trace gases generally were low. In other emissions, significant, but variable, concentrations of sulfur gases were measured. The 18 May eruption produced nuées ardentes, lightning flashes, and volcanic hail.

  13. Problems in the climatology of the 1980 Mount St. Helens eruptions. [surface heat and water budgets

    NASA Technical Reports Server (NTRS)

    Critchfield, H. J.

    1982-01-01

    A brief review of the effects of climate and weather on the 1980 Mount St. Helens eruptions and the subsequent dispersion of ash and gases and the reciprocal influences of the eruptions on climate and climatology is presented. The effects of mesoscale destruction of snow fields and vegetation, a revised mountain profile, and ash deposits are addressed along with impacts on hemispheric climate and disruption of normal climatological observations, in the areas directly affected by the explosions and ashfall. Environmental and economic consequences are also considered.

  14. The Stars Belong to Everyone: Astronomer and Science Writer Dr. Helen Sawyer Hogg (1905-1993)

    NASA Astrophysics Data System (ADS)

    Cahill, Maria J.

    2011-05-01

    University of Toronto astronomer and science writer Helen Sawyer Hogg (President of the AAVSO 1939-41) served her field through research, teaching, and administrative leadership. Additionally, she reached out to students and the public through her Toronto Star newspaper column entitled "With the Stars" for thirty years; she wrote The Stars Belong to Everyone, a book that speaks to a lay audience; she hosted a successful television series entitled Ideas; and she delivered numerous speeches at scientific conferences, professional women's associations, school programs, libraries, and other venues. This paper will illumine her life and the personal and professional forces that influenced her work.

  15. Effect of the May-June Mount St. Helens eruptions on precipitation chemistry in central Colorado

    NASA Astrophysics Data System (ADS)

    Lewis, William M.; Grant, Michael C.

    Bulk precipitation chemistry for the interval 17 May to 12 June 1980, when the Mount St. Helens volcano was intermittently erupting, was compared with similar data over the same interval in previous years at a site in central Colorado. Although phosphorus, chloride and paniculate loading values were higher than in previous years, no significant differences exist for these or other variables, indicating that the volcanic effect on chemical loading from the atmosphere at this site was within the ordinary range of variability for bulk precipitation chemistry.

  16. In Memory of Helen Meriwether Lewis Thomas August 21, 1905 - August 6, 1997

    NASA Astrophysics Data System (ADS)

    Hoffleit, Dorrit

    2000-08-01

    Helen Lewis Thomas was Secretary to Leon Campbell, the first Recorder of the AAVSO, from 1934 to 1937, but worked intermittently on variable stars at Harvard from 1927 until World War II. In 1948 she earned the third Ph.D degree in the History of Science awarded at Harvard or Radcliffe, being the first American woman to receive this degree. A most versatile scholar, she was successful in a variety of careers ranging from Engineer at the Raytheon electronics company to Head of Publications at the M.I.T. Laboratory of Electronics. She maintained a lifelong interest in the AAVSO.

  17. Revised tephra volumes for Mount St. Helens and Glacier Peak volcanoes

    NASA Astrophysics Data System (ADS)

    Nathenson, M.

    2015-12-01

    Isopach maps from 8 tephra eruptions from Mount St. Helens were reported in Carey et al. (1995) and for 3 eruptions from Glacier Peak in Gardner et al. (1998). These isopach data only define single slopes on a thickness versus square root of area plot (Fierstein and Nathenson, 1992) whereas one expects a second slope in the medial to distal region for larger eruptions. A model was proposed by Carey et al. (1995) for estimating the second slope to calculate volumes. A more recent study by Sulpizio (2005) for estimating the second slope involves a systematic analysis of many eruptions to provide correlation equations. The purpose of this study is to recalculate the volumes of Mount St. Helens and Glacier Peak eruptions and compare results from the two methods for estimating second slopes. In order to gain some perspective on the methods for estimating the second slope, we use data for thickness versus distance beyond the last isopach that is available for some of the eruptions. The thickness versus square root of area method is extended to thickness versus distance by developing an approximate relation between the two, assuming elliptical isopachs. Thickness versus distance data tend to support the Sulpizio method. The volumes derived using the Sulpizio method are 20 % or less of the values for the Mount St. Helens layers given in Carey et al. (1995) and about 50 % of the values for the Glacier Peak layers given in Gardner et al (1998). For example, for Mount St. Helens layer Wn, the volume calculated from the isopachs is 0.55 km3, using the Carey et al. (1995) method it is 7.7 km3, and using the Sulpizio (2005) method it is 1.4 km3. Carey, S., Gardner, J., and Sigurdsson, H., 1995, J. Volc. and Geoth. Res. 66, 185-202. Fierstein, J., and Nathenson, M., 1992, Bull. Volc. 54, 156-167. Gardner, J.E., Carey, S., and Sigurdsson, H., 1998, Geol. Soc. of Am. Bull. 110, 173-187. Sulpizio, R., 2005, J. Volc. Geoth. Res. 145, 315-336.

  18. Helen Flanders Dunbar, John Dewey, and clinical pragmatism: reflections on method in psychosomatic medicine and bioethics.

    PubMed

    Hart, Curtis W

    2002-01-01

    This article outlines the method utilized by physicians and major figures in the founding of Clinical Pastoral Education, Helen Flanders Dunbar, in her work of 1943, Psychosomatic Diagnosis, and relates it to the currently evolving approach in bioethics known as clinical pragmatism. It assesses Dewey's influence on both Dunbar in psychosomatic medicine and clinical pragmatism in bioethics, and illustrates the breadth of influence of the school of philosophical thought known as pragmatism with which Dewey's name and those of William James and Charles Sanders Pierce are most often identified.

  19. Airborne studies of the emissions from the volcanic eruptions of mount st. Helens.

    PubMed

    Hobbs, P V; Radke, L F; Eltgroth, M W; Hegg, D A

    1981-02-20

    The concentrations of particles less than 10 micrometers in diameter in the ash emissions from Mount St. Helens have been more than 1000 times greater than those in the ambient air. Mass loadings of particles less than 2 micrometers in diameter were generally several hundred micrograms per cubic meter. In the ash clouds, produced by the large eruption on 18 May 1980, the concentrations of several trace gases generally were low. In other emissions, significant, but variable, concentrations of sulfur gases were measured. The 18 May eruption produced nuées ardentes, lightning flashes, and volcanic hail. PMID:17740388

  20. Airborne studies of the emissions from the volcanic eruptions of Mount St. Helens

    SciTech Connect

    Hobbs, P.V.; Radke, L.F.; Eltgroth, M.W.; Hegg, D.A.

    1981-01-01

    The concentrations of particles less than 10 micrometers in diameter in the ash emissions from Mount St. Helens have been more than 1000 times greater than those in the ambient air. Mass loadings of particles less than 2 micrometers in diameter were generally several hundred micrograms per cubic meter. In the ash clouds, produced by the large eruption on 18 May 1980, the concentrations of several trace gases generally were low. In other emissions, significant, but variable, concentrations of sulfur gases were measured. The 18 May eruption produced nuees ardentes, lightning flashes, and volcanic hail.

  1. Recovery of lakes in the 1980 blast zone of Mount St. Helens

    SciTech Connect

    Wissmar, R.C. )

    1990-11-01

    Over the past 10 years, following the catastrophic 1980 eruption of Mount St. Helens, considerable research has been conducted on altered and newly created lake ecosystems in different depositional regions of the blast zone. Impact and recovery characteristics have been followed for the altered Spirit Lake and two newly created lakes S. F. Castle and Coldwater Lakes. During the 1980 eruption, Spirit Lake was directly impacted by debris avalanches and pyroclastic flows. The unique characteristics of the Mount St. Helens volcanic eruption and geochemistry, such as low inputs of sulfate and high loadings of organics from devastated forests to lakes, combined to form chemical environments favorable to biological activity. Even though weathering, organic and microbial reactions were evidently the important processes regulating alkalinity of these lakes, patterns of changes in pH, total alkalinity, and dissolved organic carbon and changes in microbial assemblages and processes also suggested a sequence of biological reactions that occurred during the early recovery period of 1980 and 1981. The biological recovery of the lakes via succession of microbial reactions suggests a tendency for the higher energy producing reactions to dominate lesser energy producing reactions. As turbid and high suspended particulate matter levels decreased, phytoplankton primary production increased to produce mixed bacteria-phytoplankton-zooplankton communities.

  2. Zircon reveals protracted magma storage and recycling beneath Mount St. Helens

    USGS Publications Warehouse

    Claiborne, L.L.; Miller, C.F.; Flanagan, D.M.; Clynne, M.A.; Wooden, J.L.

    2010-01-01

    Current data and models for Mount St. Helens volcano (Washington, United States) suggest relatively rapid transport from magma genesis to eruption, with no evidence for protracted storage or recycling of magmas. However, we show here that complex zircon age populations extending back hundreds of thousands of years from eruption age indicate that magmas regularly stall in the crust, cool and crystallize beneath the volcano, and are then rejuvenated and incorporated by hotter, young magmas on their way to the surface. Estimated dissolution times suggest that entrained zircon generally resided in rejuvenating magmas for no more than about a century. Zircon elemental compositions reflect the increasing influence of mafic input into the system through time, recording growth from hotter, less evolved magmas tens of thousands of years prior to the appearance of mafic magmas at the surface, or changes in whole-rock geochemistry and petrology, and providing a new, time-correlated record of this evolution independent of the eruption history. Zircon data thus reveal the history of the hidden, long-lived intrusive portion of the Mount St. Helens system, where melt and crystals are stored for as long as hundreds of thousands of years and interact with fresh influxes of magmas that traverse the intrusive reservoir before erupting. ?? 2010 Geological Society of America.

  3. The mechanisms of fine particle generation and electrification during Mount St. Helens volcanic eruption

    NASA Technical Reports Server (NTRS)

    Cheng, R. J.

    1982-01-01

    Microscopical investigation of volcanic ash collected from ground stations during Mount St. Helens eruptions reveal a distinctive bimodel size distribution with high concentrations of particle ranges at (1) 200-100 microns and (2) 20-0.1 microns. Close examination of individual particles shows that most larger ones are solidified magma particles of porous pumice with numerous gas bubbles in the interior and the smaller ones are all glassy fragments without any detectable gas bubbles. Elemental analysis demonstrates that the fine fragments all have a composition similar to that of the larger pumice particles. Laboratory experiments suggest that the formation of the fine fragments is by bursting of glassy bubbles from a partially solidified surface of a crystallizing molten magma particle. The production of gas bubbles is due to the release of absorbed gases in molten magma particles when solubility decreases during phase transition. Diffusion cloud chamber experiments strongly indicate that sub-micron volcanic fragments are highly hygroscopic and extremely active as cloud condensation nuclei. Ice crystals also are evidently formed on those fragments in a supercooled (-20 C) cloud chamber. It has been reported that charge generation from ocean volcanic eruptions is due to contact of molten lava with sea water. This seems to be insufficient to explain the observed rapid and intense lightning activities over Mount St. Helens eruptions. Therefore, a hypothesis is presented here that highly electrically charged fine solid fragments are ejected by bursting of gas bubbles from the surface of a crystallizing molten magma particles.

  4. Posteruption glacier development within the crater of Mount St. Helens, Washington, USA

    USGS Publications Warehouse

    Schilling, S.P.; Carrara, P.E.; Thompson, R.A.; Iwatsubo, E.Y.

    2004-01-01

    The cataclysmic eruption of Mount St. Helens on May 18, 1980, resulted in a large, north-facing amphitheater, with a steep headwall rising 700 m above the crater floor. In this deeply shaded niche a glacier, here named the Amphitheater glacier, has formed. Tongues of ice-containing crevasses extend from the main ice mass around both the east and the west sides of the lava dome that occupies the center of the crater floor. Aerial photographs taken in September 1996 reveal a small glacier in the southwest portion of the amphitheater containing several crevasses and a bergschrund-like feature at its head. The extent of the glacier at this time is probably about 0.1 km2. By September 2001, the debris-laden glacier had grown to about 1 km2 in area, with a maximum thickness of about 200 m, and contained an estimated 120,000,000 m3 of ice and rock debris. Approximately one-third of the volume of the glacier is thought to be rock debris derived mainly from rock avalanches from the surrounding amphitheater walls. The newly formed Amphitheater glacier is not only the largest glacier on Mount St. Helens but its aerial extent exceeds that of all other remaining glaciers combined. Published by University of Washington.

  5. Water fact sheet; evolution of sediment yield from Mount St. Helens, Washington, 1980-1993

    USGS Publications Warehouse

    Costa, John E.

    1994-01-01

    The most enduring geological consequence of the eruption of Mount St. Helens, Washington, on May 18, 1980, and the most costly single element in the recovery effort, has been the persistent downstream sedimentation caused by erosion of the approximately 3 cubic kilometers (km3) of sediment deposited on the landscape surrounding the volcano. Most of the sediment was associated with the emplacement of a 2.8 km3 debris avalanche in the upper part of the watershed of the North Fork Toutle River, and debris flows in the channels of the South Fork Toutle River, Pine Creek, Swift Creek, and Muddy River. An additional 0.2-0.3 km3 of volcanic material was emplaced by pyroclastic flows, blasts, and ash fall. Part of this vast quantity of volcaniclastic sediment has been subsequently eroded by runoff and streamflow. This brief report summarizes the changes in sediment yield at five locations around Mount St. Helens in the first 13 years following the May 18, 1980 eruption.

  6. Democracy and Schooling in California: The Legacy of Helen Heffernan and Corinne Seeds. Historical Studies in Education

    ERIC Educational Resources Information Center

    Weiler, Kathleen

    2011-01-01

    Helen Heffernan and Corinne Seeds were nationally recognized as leaders of the progressive education movement and were key figures in what was probably the most concerted attempt to put the ideals of progressive education into practice in a state-wide system of public education in the United States. This book examines the struggle over public…

  7. Towards a Transactional View of Rhetorical and Feminist Theory: Rereading Helen Cixous's "The Laugh of the Medusa."

    ERIC Educational Resources Information Center

    Biesecker, Barbara A.

    1992-01-01

    Argues that by rereading Helene Cixous's "The Laugh of Medusa" as a rhetoric--that is, an essay which posits what can and must be done by women if they are to intervene effectively in the public sphere through written or oral discourse--both rhetorical and feminist theory and criticism are enriched. (SR)

  8. Impossible Practice and Theories of the Impossible: A Response to Helene Illeris's "Potentials of Togetherness"

    ERIC Educational Resources Information Center

    Kallio-Tavin, Mira

    2014-01-01

    In a recent commentary in "Studies in Art Education," Helene Illeris (2013) discussed the idea of "performative experimental communities" via a critique of visual culture pedagogy and the romanticism of community-oriented art education in Nordic countries. Illeris underpinned her arguments with Jean-Luc Nancy's (1997)…

  9. An investigation of pre-eruptive deformation for the 2004 eruption of Mount St. Helens using persistent scatterer interferometry

    NASA Astrophysics Data System (ADS)

    Welch, M.; Schmidt, D. A.

    2014-12-01

    The volcanoes of the Cascade Range pose a legitimate threat to people living in the Pacific Northwest. Mt St Helens, which erupted in 2004 as a part of a dome building event, is a notable example of this danger. Deformation and seismicity are known indicators of volcanic activity and can provide warning of an imminent eruption. In the weeks leading up to the 2004 eruption, a shallow earthquake swarm was detected under St. Helens, suggesting ongoing deformation with its source beneath the edifice. A campaign GPS survey conducted in 2000 found no evidence of deformation. The sole continuous GPS station that was operational prior to the eruption (located ~9 km away from the crater) began moving only with the onset of the earthquake swarm. Because of the lack of ground based geodetic instruments in the near-field of Mt St Helens at the time of the 2004 eruption, it is unknown whether pre-eruptive deformation occurred on the edifice or solely within crater. InSAR is the only method available to conclusively determine whether the 2004 eruption was preceded by deformation of the edifice. Previous work explored this question using standard 2-pass interferometry, but the results were inconclusive. The main obstacle to implementing InSAR methods in the Cascades region is phase decorrelation due to the presence of both dense forest and snow for most of the year. We revisit the available InSAR data for St. Helens by experimenting with the application of the Persistent Scatterers and Distributed Scatterers processing techniques in order to overcome the decorrelation problem. By using these techniques on the question of Mt St Helens pre-eruptive deformation, we will demonstrate the viability of their application to the entire Northwest region as a low cost, low maintenance, monitoring tool.

  10. Photogeologic maps of the 2004-2005 Mount St. Helens eruption: Chapter 10 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

    USGS Publications Warehouse

    Herriott, Trystan M.; Sherrod, David R.; Pallister, John S.; Vallance, James W.; Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

    2008-01-01

    The 2004-5 eruption of Mount St. Helens, still ongoing as of this writing (September 2006), has comprised chiefly lava dome extrusion that produced a series of solid, faultgouge-mantled dacite spines. Vertical aerial photographs taken every 2 to 4 weeks, visual observations, and oblique photographs taken from aircraft and nearby observation points provide the basis for two types of photogeologic maps of the dome--photo-based maps and rectified maps. Eight map pairs, covering the period from October 1, 2004, through December 15, 2005, document the development of seven spines: an initial small, fin-shaped vertical spine; a north-south elongate wall of dacite; two large and elongate recumbent spines (“whalebacks”); a tall and elongate inclined spine; a smaller bulbous spine; and an initially endogenous spine extruded between remnants of preceding spines. All spines rose from the same general vent area near the southern margin of the 1980s lava dome. Maps also depict translation and rotation of active and abandoned spines, progressive deformation affecting Crater Glacier, and distribution of ash on the crater floor from phreatic and phreatomagmatic explosions. The maps help track key geologic and geographic features in the rapidly changing crater and help date dome, gouge, and ash samples that are no longer readily correlated to their original context because of deformation in a dynamic environment where spines extrude, deform, slough, and are overrun by newly erupted material.

  11. Anthropology in a postcolonial colony: Helen I. Safa's contribution to Puerto Rican ethnography.

    PubMed

    Duany, Jorge

    2010-01-01

    This article assesses Helen I. Safa's legacy to anthropological thought in Puerto Rico. The first part of the article locates Safa's research on the Island within a long tradition of fieldwork by U.S. scholars since the early twentieth century. More recent research, conducted mostly by Puerto Rican women anthropologists and other social scientists, has expanded upon Safa's insights on gender and work. The second part of the essay analyzes Safa's major empirical work, The Urban Poor of Puerto Rico: A Study in Development and Inequality. Above all, this book helped overcome the theoretical impasse over the culture of poverty that characterized much of urban anthropology during the 1960s and 1970s. The article concludes with an appraisal of the relevance of Safa's work for the ethnography of contemporary Puerto Rico.

  12. Monitoring a restless volcano: The 2004 eruption of Mount St. Helens

    USGS Publications Warehouse

    Gardner, C.

    2005-01-01

    Although the precise course of volcanic activity is difficult to predict, volcanologists are pretty adept at interpreting volcanic signals from well-monitored volcanoes in order to make short-term forecasts. Various monitoring tools record effects to give us warning before eruptions, changes in eruptive behavior during eruptions, or signals that an eruption is ending. Foremost among these tools is seismic monitoring. The character, size, depth and rate of earthquakes are all important to the interpretation of what is happening belowground. The first inkling of renewed activity at Mount St. Helens began in the early hours of Sept. 23, when a seismic swarm - tens to hundreds of earthquakes over days to a week - began beneath the volcano. This article details the obervations made during the eruptive sequence.

  13. Gaseous constituents in the plume from eruptions of Mount St. Helens

    NASA Technical Reports Server (NTRS)

    Inn, E. C. Y.; Vedder, J. F.; Condon, E. P.; Ohara, D.

    1981-01-01

    Measurements in the stratosphere of gaseous constituents in the plume of Mount St. Helens were obtained during five flights of the NASA U-2 aircraft between 19 May and 17 June 1980. Mixing ratios from gas chromatographic measurements on samples acquired about 24 hours after the initial eruption show considerable enhancement over nonvolcanic concentrations for sulfur dioxide (more than 1000 times), methyl chloride (about 10 times), and carbon disulfide (more than 3 times). The mixing ratio of carbonyl sulfide was comparable to nonvolcanic mixing ratios although 3 days later it was enhanced two to three times. Ion chromatography measurements on water-soluble constituents are also reported. Very large concentrations of chloride, nitrate, and sulfate ions were measured, implying large mixing ratios for the water-soluble gaseous constituents from which the anions are derived. Measurements of radon-222 present in the plume are also reported.

  14. Magmatic model for the Mount St. Helens blast of May 18, 1980

    SciTech Connect

    Eichelberger, J.C.; Hayes, D.B.

    1982-09-10

    Analytical and numerical solutions to the hydrodynamic equations of motion, constrained by physical properties of juvenile ejecta in the Mount St. Helens blast deposit, were used to investigate magmatic conditions required to produce the initial devastating blast phase of the eruption of May 18, 1980. Evidence that the blast was magmatic includes equivalence in volume of juvenile blast ejecta to preeruption inflation of the cone, substantial vesicularity of this ejecta, and continued vesiculation of large juvenile clasts after eruption. Observed or inferred ejecta velocities of 100 to 250 m/s are shown to require 0.2 to 0.7 wt% water vapor preexisting in magma unloaded by a landslide 200 to 900 m thick. These conditions imply total magmatic water contents of 0.7 to 1.7 wt%, respectively. Such low required water content suggests that volcanic blasts may be regarded as a normal consequence of magma intrusion into an unstable edifice.

  15. Was the 18 May 1980 lateral blast at Mt St Helens the product of two explosions?

    USGS Publications Warehouse

    Hoblitt, R.P.

    2000-01-01

    The 18 May 1980 lateral blast at Mt St Helens has been interpreted as the product of a single explosion by some stratigraphers and as two closely spaced explosions by others. The stratigraphic evidence that bears on this question is inconclusive; strata change dramatically over short distances and this complexity provides wide latitude for interpretation. Some independent non-stratigraphic evidence, however, suggests that the blast was the product of two explosions or clusters of explosions. The independent evidence comes from eyewitness accounts and photographs, from satellite sensors, and from seismic records. This paper reviews the pertinent evidence, offers a new interpretation, and concludes that the blast was indeed the product of two explosions or clusters of explosions.

  16. Health-hazard-evaluation report MHETA 89-362-2027, Helen Mining Company, Homer City, Pennsylvania

    SciTech Connect

    Ferguson, R.P.

    1990-03-01

    In response to a request from the United Mine Workers of America, an investigation was made of possible hazardous working conditions at the Helen Mining Company, Homer City, Pennsylvania. One of the tipple operators had complained of headaches, dizziness and skin rashes from working with a mixture of solvents used in the float/sink test operation. The solvents included perchloroethylene and dibromomethane. A week prior to receiving the request, the use of dibromomethane had been discontinued. Consequently, on the visit to the site, no traces of dibromomethane were found. After engineering controls were installed, only one of seven personal breathing zone samples detected any perchloroethylene, and that sample was 0.12 parts per million, at the limit of detection. The author concludes that a hazard from perchloroethylene did not exist at the time of the evaluation. The author recommends replacing the rubber/cloth type glove being used with either a Teflon or Viton glove, and enclosing the work table.

  17. Hydrogen-isotope evidence for extrusion mechanisms of the Mount St Helens lava dome

    NASA Technical Reports Server (NTRS)

    Anderson, Steven W.; Fink, Jonathan H.

    1989-01-01

    Hydrogen isotope analyses were used to determine water content and deuterium content for 18 samples of the Mount St Helens dome dacite in an attempt to identify the triggering mechanisms for periodic dome-building eruptions of lava. These isotope data, the first ever collected from an active lava dome, suggest a steady-state process of magma evolution combining crystallization-induced volatile production in the chamber with three different degassing mechanisms: closed-system volatile loss in the magma chamber, open-system volatile release during ascent, and kinetically controlled degassing upon eruption at the surface. The data suggest the future dome-building eruptions may require a new influx of volatile-rich magma into the chamber.

  18. Forward scattering and backscattering of solar radiation by the stratospheric limb after Mount St. Helens eruption

    NASA Technical Reports Server (NTRS)

    Ackerman, M.; Lippens, C.

    1982-01-01

    Stratospheric limb radiance profiles versus altitude of closest approach of the line of sight to the Earth's surface have been measured before and after the Mount St. Helens eruptions by means of photographs taken from a Sun-oriented balloon gondola floating above 35 km altitude over France. Preliminary data were reported for flights in October 1979 and in May and June 1980. The radiance integrated along the line of sight as in-situ radiance (R) can be derived taking into account absorption by ozone and air. The onion peeling inversion method was used to derive the vertical radiance (R) profiles respectively. The values of R were determined in the solar azimuth. The solar elevation angles are chosen larger for the backscattering observation than for the forward scattering observation to deal with as similar illumination conditions as possible despite the Earth's sphericity.

  19. In the path of destruction - eyewitness chronicles of Mount St. Helens

    USGS Publications Warehouse

    Waitt, Richard B.

    2015-01-01

    “The air had no oxygen, like being trapped underwater…I was being cremated, the pain unbearable.”-- Jim Scymanky“I was on my knees, my back to the hot wind. It blew me along, lifting my rear so I was up on my hands…It was hot but I didn’t feel burned—until I felt my ears curl.”—Mike HubbardA napping volcano blinked awake in March 1980. Two months later, the mountain roared. Author Richard Waitt was one of the first to arrive following the mountain’s early rumblings. A geologist with intimate knowledge of Mount St. Helens, Waitt delivers a detailed and accurate chronicle of events. The eruption story unfolds through unforgettable, riveting narratives—the heart of a masterful chronology that also delivers engrossing science, history, and journalism.

  20. Dynamics of seismogenic volcanic extrusion at Mount St Helens in 2004-05

    USGS Publications Warehouse

    Iverson, R.M.; Dzurisin, D.; Gardner, C.A.; Gerlach, T.M.; LaHusen, R.G.; Lisowski, M.; Major, J.J.; Malone, S.D.; Messerich, J.A.; Moran, S.C.; Pallister, J.S.; Qamar, A.I.; Schilling, S.P.; Vallance, J.W.

    2006-01-01

    The 2004-05 eruption of Mount St Helens exhibited sustained, near-equilibrium behaviour characterized by relatively steady extrusion of a solid dacite plug and nearly periodic shallow earthquakes. Here we present a diverse data set to support our hypothesis that these earthquakes resulted from stick-slip motion along the margins of the plug as it was forced incrementally upwards by ascending, solidifying, gas-poor magma. We formalize this hypothesis with a dynamical model that reveals a strong analogy between behaviour of the magma-plug system and that of a variably damped oscillator. Modelled stick-slip oscillations have properties that help constrain the balance of forces governing the earthquakes and eruption, and they imply that magma pressure never deviated much from the steady equilibrium pressure. We infer that the volcano was probably poised in a near-eruptive equilibrium state long before the onset of the 2004-05 eruption. ??2006 Nature Publishing Group.

  1. Didymus the blind: an unknown precursor of Louis Braille and Helen Keller.

    PubMed

    Lascaratos, J; Marketos, S

    1994-01-01

    The present study presents the case of Didymus the Blind, worthy author, philosopher and theologian of the 4th century AD. Blinded by ophthalmia at the age of four years, Didymus succeeded in achieving great learning in the philosophical and natural sciences. He began his education by using a system which was remarkably like Braille, that is reading letters engraved into the surface of wood by touch and subsequently furthering his knowledge by listening. This learning process of Didymus the Blind appears as the precursor of Louis Braille who invented the educational system of reading embossed dots by touch. Like Didymus, Braille lost his vision in infancy (at three years of age). Another parallel of Didymus' career and written works is found in the example and achievements of Helen Keller.

  2. Intrusive and extrusive growth of the Mount St Helens lava dome

    NASA Technical Reports Server (NTRS)

    Fink, Jonathan H.; Malin, Michael C.; Anderson, Steven W.

    1990-01-01

    High-resolution, digital topographic maps of the Mount St. Helens dome derived from aerial photographs are used here to make a quantitative assessment of the partitioning of magma into endogenous intrusion and exogenous lobes. The endogenous growth is found to be predictable, which shows that the cooling dome controls its own development independently of such deep-seated factors as magma overpressure and extrusion rate. The observed regular decrease in exogenous growth rate also allows volume prediction. Knowledge of the volume can be used to determine when an ongoing eruptive event should end. Finally, the observed transition from predominantly exogenous to predominantly endogenous growth reflects the increase in crust thickness, which in turn seems to depend on long repose periods rather than some fundamental change in the character of the dome.

  3. Deep earthquakes beneath Mount St. Helens: Evidence for magmatic gas transport?

    USGS Publications Warehouse

    Weaver, C.S.; Zollweg, J.E.; Malone, S.D.

    1983-01-01

    Small-magnitude earthquakes began beneath Mount St. Helens 40 days before the eruption of 20 March 1982. Unlike earlier preeruption seismicity for this volcano, which had been limited to shallow events (less than 3 kilometers), many of these earthquakes were deep (between 5 and 11 kilometers). The location of these preeruptive events at such depth indicates that a larger volume of the volcanic system was affected prior to the 20 March eruption than prior to any of the earlier dome-building eruptions. The depth-time relation between the deep earthquakes and the explosive onset of the eruption is compatible with the upward migration of magmatic gas released from a separate deep reservoir.

  4. Thermal property measurements in a fresh pumice flow at Mt. St. Helens

    SciTech Connect

    Hardee, H.C.

    1981-03-01

    A thermal penetrator that was air dropped into a freshly emplaced pumice flow at Mt. St. Helens yielded information on the in-situ thermal properties of the pumice. The in-situ conductivity-density-specific heat product at a depth of 60 cm was found to be 7.24 x 10/sup -5/ cal/sup 2/cm//sup 4/ s- /sup 0/C/sup 2/ at an average pumice temperature of 200 /sup 0/C. Using this data, values for the average in-situ thermal conductivity (2.9 x 10/sup -4/ cal/cm-s-/sup 0/C) and thermal diffusivity (1.2 x 10/sup -3/ cm/sup 2//s) were estimated. These thermal properties are of use in studies of pumice cooling and in the interpretation of infrared remote sensing data.

  5. Evaluation of heat flow and its geological implications on Mt. St. Helens

    SciTech Connect

    Grady, T.; Adams, E.; Brown, R.L.; Sato, A.

    1982-04-01

    A study to determine the heat flux pattern in the vicinity of Mt. St. Helens was undertaken as part of a program to evaluate the effects of the eruption on future snowpack conditions in the area. Subsurface temperature and low energy refraction seismic studies were made during the early spring in 1981 to determine both the heat flux in the area of pyroclastic deposition and its potential source. In addition, samples were collected for later laboratory determination of thermal conductivity and diffusivity. Results indicate that the heat flow values in the area of pyroclastic deposition are as large as forty times greater than the heat flow values measured on Mt. Adams and Mt. Hood during the same period. The highest heat flow values appear to coincide with a pumice flow unit on the north side of the mountain.. Comparison with work done on the eruption of Mt. Komagatake indicates that the large heat flow values continue for several years.

  6. Chronology and pyroclastic stratigraphy of the May 18, 1980, eruption of Mount St. Helens, Washington

    NASA Technical Reports Server (NTRS)

    Criswell, C. William

    1987-01-01

    The eruption of Mount St. Helens on May 18, 1980 can be subdivided into six phases: the paroxysmal phase I, the early Plinian phase II, the early ash flow phase III, the climactic phase IV, the late ash flow phase V, and phase VI, the activity of which consisted of a low-energy ash plume. These phases are correlated with stratigraphic subunits of ash-fall tephra and pyroclastic flow deposits. Sustained vertical discharge of phase II produced evolved dacite with high S/Cl ratios. Ash flow activity of phase III is attributed to decreases in gas content, indicated by reduced S/Cl ratios and increased clast density of the less evolved gray pumice. Climactic events are attributed to vent clearing and exhaustion of the evolved dacite.

  7. Beam Diagnostics On The HELEN Laser System At Atomic Weapons Research Establishment (AWRE)

    NASA Astrophysics Data System (ADS)

    Cooke, R. L.; Norman, C. J.; Danson, C. N.

    1982-11-01

    The HELEN laser system at the Atomic Weapons Research Establishment, is a two beam Nd-glass laser used for the study of laser plasma phenomena relevant to weapons physics, and is capable of generating 100 J pulses of 1TW peak power in each arm. This paper presents an overview of the system with particular reference to recent developments in beam diagnostics. The diagnostics discussed fall into two categories of equal importance. Firstly, the measurement of beam parameters required for the complete analysis of experimental target data, namely laser pulse energy, pulse width, pre-pulse ratio and far-field intensity distribution; and secondly, measurement of parameters used to ensure optimum system performance such as near-field intensity distribution, amplifier gains and passive component transmission.

  8. Target diagnostics for commissioning the AWE HELEN Laser Facility 100 TW chirped pulse amplification beam

    SciTech Connect

    Eagleton, R. T.; Clark, E. L.; Davies, H. M.; Edwards, R. D.; Gales, S.; Girling, M. T.; Hoarty, D. J.; Hopps, N. W.; James, S. F.; Kopec, M. F.; Nolan, J. R.; Ryder, K.

    2006-10-15

    The capability of the HELEN laser at the Atomic Weapons Establishment Aldermaston has been enhanced by the addition of a short-pulse laser beam to augment the twin opposing nanosecond time scale beams. The short-pulse beam utilizes the chirped pulse amplification (CPA) technique and is capable of delivering up to 60 J on target in a 500 fs pulse, around 100 TW, at the fundamental laser wavelength of 1.054 {mu}m. During the commissioning phase a number of diagnostic systems have been fielded, these include: x-ray pinhole imaging of the laser heated spot, charged particle time of flight, thermoluminescent dosimeter array, calibrated radiochromic film, and CR39 nuclear track detector. These diagnostic systems have been used to verify the performance of the CPA beam to achieve a focused intensity of around 10{sup 19} W cm{sup -2} and to underwrite the facility radiological safety system.

  9. Seismic and acoustic recordings of an unusually large rockfall at Mount St. Helens, Washington

    USGS Publications Warehouse

    Moran, S.C.; Matoza, R.S.; Garces, M.A.; Hedlin, M.A.H.; Bowers, D.; Scott, W.E.; Sherrod, D.R.; Vallance, J.W.

    2008-01-01

    On 29 May 2006 a large rockfall off the Mount St. Helens lava dome produced an atmospheric plume that was reported by airplane pilots to have risen to 6,000 m above sea level and interpreted to be a result of an explosive event. However, subsequent field reconnaissance found no evidence of a ballistic field, indicating that there was no explosive component. The rockfall produced complex seismic and infrasonic signals, with the latter recorded at sites 0.6 and 13.4 km from the source. An unusual, very long-period (50 s) infrasonic signal was recorded, a signal we model as the result of air displacement. Two high-frequency infrasonic signals are inferred to result from the initial contact of a rock slab with the ground and from interaction of displaced air with a depression at the base of the active lava dome. Copyright 2008 by the American Geophysical Union.

  10. Target diagnostics for commissioning the AWE HELEN Laser Facility 100 TW chirped pulse amplification beam

    NASA Astrophysics Data System (ADS)

    Eagleton, R. T.; Clark, E. L.; Davies, H. M.; Edwards, R. D.; Gales, S.; Girling, M. T.; Hoarty, D. J.; Hopps, N. W.; James, S. F.; Kopec, M. F.; Nolan, J. R.; Ryder, K.

    2006-10-01

    The capability of the HELEN laser at the Atomic Weapons Establishment Aldermaston has been enhanced by the addition of a short-pulse laser beam to augment the twin opposing nanosecond time scale beams. The short-pulse beam utilizes the chirped pulse amplification (CPA) technique and is capable of delivering up to 60J on target in a 500fs pulse, around 100TW, at the fundamental laser wavelength of 1.054μm. During the commissioning phase a number of diagnostic systems have been fielded, these include: x-ray pinhole imaging of the laser heated spot, charged particle time of flight, thermoluminescent dosimeter array, calibrated radiochromic film, and CR39 nuclear track detector. These diagnostic systems have been used to verify the performance of the CPA beam to achieve a focused intensity of around 1019Wcm-2 and to underwrite the facility radiological safety system.

  11. Gas emissions and the eruptions of Mount St. Helens through 1982

    USGS Publications Warehouse

    Casadevall, T.; Rose, W.; Gerlach, T.; Greenland, L.P.; Ewert, J.; Wunderman, R.; Symonds, R.

    1983-01-01

    The monitoring of gas emissions from Mount St. Helens includes daily airborne measurements of sulfur dioxide in the volcanic plume and monthly sampling of gases from crater fumaroles. The composition of the fumarolic gases has changed slightly since 1980: the water content increased from 90 to 98 percent, and the carbon dioxide concentrations decreased from about 10 to 1 percent. The emission rates of sulfur dioxide and carbon dioxide were at their peak during July and August 1980, decreased rapidly in late 1980, and have remained low and decreased slightly through 1981 and 1982. These patterns suggest steady outgassing of a single batch of magma (with a volume of not less than 0.3 cubic kilometer) to which no significant new magma has been added since mid-1980. The gas data were useful in predicting eruptions in August 1980 and June 1981.

  12. Monitoring vegetation recovery patterns on Mount St. Helens using thermal infrared multispectral data

    NASA Technical Reports Server (NTRS)

    Langran, K. J.

    1985-01-01

    The eruptions of Mount St. Helens created new surfaces by stripping and implacing large volumes of eroded material and depositing tephra in the blast area and on the flanks of the mountain. Areas of major disturbance are those in the blast zone that were subject to debris avalanche, pyroclastic flows, mudflows, and blowdown and scorched timber; and those outside the blast zone that received extensive tephra deposits. These zones represent a spectrum of disturbance types and intensities that can be indexed by temperature, impact force, and depth of subsequent deposition. This paper describes an application of NASA's Thermal Infrared Multispectral Scanner (TIMS) in monitoring vegetation recovery patterns in disturbed areas. Preliminary study results indicate a significant correlation between measured effective radiant temperature and vegetated/nonvegetated areas, percent vegetation cover, and vegetation type.

  13. The therapeutic release of anger: Helen Watkins's silent abreaction and subsequent elaborations of the anger rock.

    PubMed

    Krakauer, Sarah Y

    2009-01-01

    This paper summarizes Helen Watkins's (1980) silent abreaction technique for releasing anger and the subsequent elaborations it has inspired. Discussion of Watkins's seminal article incorporates her verbatim account of the technique, 2 clinical applications, and her encouragement of further adaptations. Other scholars' subsequent contributions include an adaptation for dissociative identity disorder, brief treatment of constant pain syndrome, and inpatient treatment of a suicidally depressed, dissociative survivor of sexual abuse. Commonalities and distinctions among Watkins's work and these modifications are discussed. New case material from the author's practice illustrate further elaborations, with emphasis on the role of releasing anger in the resolution of dissociative defenses and internal fragmentation in dissociative clients. To enhance the clinical utility of this paper, verbatim passages are included for all case illustrations in H. H. Watkins (1980), the 3 published elaborations, and the new case material.

  14. Vapor transfer prior to the October 2004 eruption of Mount St. Helens, Washington

    USGS Publications Warehouse

    Kent, A.J.R.; Blundy, J.; Cashman, K.V.; Copper, K.M.; Donnelly, C.; Pallister, J.S.; Reagan, M.; Rowe, M.C.; Thornber, C.R.

    2007-01-01

    Dome lavas from the 2004 eruption of Mount St. Helens show elevated Li contents in plagioclase phenocrysts at the onset of dome growth in October 2004. These cannot be explained by variations in plagioclase-melt partitioning, but require elevated Li contents in coexisting melt, a fact confirmed by measurements of Li contents as high as 207 ??g/g in coexisting melt inclusions. Similar Li enrichment has been observed in material erupted prior to and during the climactic May 1980 eruption, and is likewise best explained via pre-eruptive transfer of an exsolved alkali-rich vapor phase derived from deeper within the magma transport system. Unlike 1980, however, high Li samples from 2004 show no evidence of excess (210Pb)/(226 Ra), implying that measurable Li enrichments may occur despite significant differences in the timing and/or extent of magmatic degassing. Diffusion modeling shows that Li enrichment occurred within -1 yr before eruption, and that magma remained Li enriched until immediately before eruption and cooling. This short flux time and the very high Li contents in ash produced by phreatomagmatic activity prior to the onset of dome extrusion suggest that vapor transfer and accumulation were associated with initiation of the current eruption. Overall, observation of a high Li signature in both 1980 and 2004 dacites indicates that Li enrichment may be a relatively common phenomenon, and may prove useful for petrologic monitoring of Mount St. Helens and other silicic volcanoes. Lithium diffusion is also sufficiently rapid to constrain vapor transfer on similar time scales to short-lived radionuclides. ?? 2007 Geological Society of America.

  15. Mass Intrusion at Mount St. Helens (WA) From Temporal Gravity Variations

    NASA Astrophysics Data System (ADS)

    Battaglia, M.; Lisowski, M.; Dzurisin, D.; Poland, M. P.; Schilling, S. P.; Diefenbach, A. K.; Wynn, J.

    2015-12-01

    Repeated high-precision gravity measurements made at Mount St. Helens (WA) have revealed systematic temporal variations in the gravity field several years after the end of the 2004-2008 dome-building eruption. Changes in gravity with respect to a stable reference station 36 km NW of the volcano were measured at 10 sites on the volcanic edifice and at 4 sites far afield (10 to 36 km) from the summit in August 2010, August 2012 and August 2014. After simulating and removing the gravity signal associated with changes in mass of the crater glacier, the local hydrothermal aquifer, and vertical deformation, the residual gravity field observed at sites near the volcano's summit significantly increased with respect to the stable reference site during 2010-2012 (maximum change 48 ± 15 mgal). No significant change was measured during 2012-2014. The pattern of gravity increase is radially symmetrical, with a half-width of about 2.5 km and a point of maximum change centered at the 2004-2008 lava dome. Forward modeling of residual gravity data using the same source geometry, depth, and location as that inferred from geodetic data (a spheroidal source centered 7.5 km beneath the 2004-2008 dome) indicates a mass increase rate of the order of 1011 kg/year. For a reasonable magma density (~2250 kg/m3), the volume rate of magma intrusion beneath the summit region inferred from gravity (~ 0.1 km3/yr) greatly exceeds the volume inferred from inversion of geodetic data (0.001 km3/yr between 2008-2011), suggesting that either magma compressibility or other processes are important aspects of magma storage at Mount St. Helens, or that the data argue for a different source.

  16. A continuous record of intereruption velocity change at Mount St. Helens from coda wave interferometry

    USGS Publications Warehouse

    Hotovec-Ellis, Alicia J.; Gomberg, Joan S.; Vidale, John; Creager, Ken C.

    2014-01-01

    In September 2004, Mount St. Helens volcano erupted after nearly 18 years of quiescence. However, it is unclear from the limited geophysical observations when or if the magma chamber replenished following the 1980–1986 eruptions in the years before the 2004–2008 extrusive eruption. We use coda wave interferometry with repeating earthquakes to measure small changes in the velocity structure of Mount St. Helens volcano that might indicate magmatic intrusion. By combining observations of relative velocity changes from many closely located earthquake sources, we solve for a continuous function of velocity changes with time. We find that seasonal effects dominate the relative velocity changes. Seismicity rates and repeating earthquake occurrence also vary seasonally; therefore, velocity changes and seismicity are likely modulated by snow loading, fluid saturation, and/or changes in groundwater level. We estimate hydrologic effects impart stress changes on the order of tens of kilopascals within the upper 4 km, resulting in annual velocity variations of 0.5 to 1%. The largest nonseasonal change is a decrease in velocity at the time of the deep Mw = 6.8 Nisqually earthquake. We find no systematic velocity changes during the most likely times of intrusions, consistent with a lack of observable surface deformation. We conclude that if replenishing intrusions occurred, they did not alter seismic velocities where this technique is sensitive due to either their small size or the finite compressibility of the magma chamber. We interpret the observed velocity changes and shallow seasonal seismicity as a response to small stress changes in a shallow, pressurized system.

  17. Attenuation and Scattering Tomography of the Deep Plumbing System of Mount St. Helens

    NASA Astrophysics Data System (ADS)

    De Siena, L.; Thomas, C.; Waite, G. P.; Moran, S. C.; Klemme, S.

    2014-12-01

    We present a combined 3D P-wave attenuation, 2D S-coda attenuation, and 3D S-coda scattering tomography model of fluid pathways, feeding systems, and sediments below Mount St. Helens (MSH) volcano between depths of 0 and 18 km. High-scattering and high-attenuation shallow anomalies are indicative of magma and fluid-rich zones within and below the volcanic edifice down to 6 km depth, where a high-scattering body outlines the top of a deeper aseismic velocity anomaly. Both the volcanic edifice and these structures induce a combination of strong scattering and attenuation on any seismic wave-field, particularly those recorded on the northern and eastern flanks of the volcanic cone. North of the cone, between depths of 0 and 10 km, a low-velocity, high-scattering, and high-attenuation north-south trending trough is attributed to thick piles of Tertiary marine sediments within the St. Helens Seismic Zone. A laterally-extended 3D scattering contrast at depths of 10 to 14 km is related to the boundary between upper and lower crust, and caused in our interpretation by the large scale interaction of the Siletz terrane with the Cascade arc crust. This contrast presents a low scattering, 4-6 km2 "hole" under the north-eastern flank of the volcano. We infer that this section represents the main path of magma ascent from depths greater than 6 km at MSH, with a small north-east shift in the lower plumbing system of the volcano. We conclude that combinations of different non-standard tomographic methods, and particularly the application of full-waveform tomography to highly heterogeneous media, represent the future of seismic volcano imaging.

  18. Attenuation and scattering tomography of the deep plumbing system of Mount St. Helens

    USGS Publications Warehouse

    De Siena, Luca; Thomas, Christine; Waite, Greg P.; Moran, Seth C.; Klemme, Stefan

    2014-01-01

    We present a combined 3-D P wave attenuation, 2-D S coda attenuation, and 3-D S coda scattering tomography model of fluid pathways, feeding systems, and sediments below Mount St. Helens (MSH) volcano between depths of 0 and 18 km. High-scattering and high-attenuation shallow anomalies are indicative of magma and fluid-rich zones within and below the volcanic edifice down to 6 km depth, where a high-scattering body outlines the top of deeper aseismic velocity anomalies. Both the volcanic edifice and these structures induce a combination of strong scattering and attenuation on any seismic wavefield, particularly those recorded on the northern and eastern flanks of the volcanic cone. North of the cone between depths of 0 and 10 km, a low-velocity, high-scattering, and high-attenuation north-south trending trough is attributed to thick piles of Tertiary marine sediments within the St. Helens Seismic Zone. A laterally extended 3-D scattering contrast at depths of 10 to 14 km is related to the boundary between upper and lower crust and caused in our interpretation by the large-scale interaction of the Siletz terrane with the Cascade arc crust. This contrast presents a low-scattering, 4–6 km2 “hole” under the northeastern flank of the volcano. We infer that this section represents the main path of magma ascent from depths greater than 6 km at MSH, with a small north-east shift in the lower plumbing system of the volcano. We conclude that combinations of different nonstandard tomographic methods, leading toward full-waveform tomography, represent the future of seismic volcano imaging.

  19. The effects of catastrophic ecosystem disturbance: the residual mammals at Mount St. Helens

    USGS Publications Warehouse

    Andersen, Douglas C.; MacMahon, James A.

    1985-01-01

    Individuals that survive the direct effects of community- or ecosystem-level disturbances, i.e., "residuals", can have major roles in determining the rate and pathway of subsequent secondary succession. The explosive eruption of the Mount St. Helens volcano on 19 May 1980 resulted in severe damage to a cast array of animal and plant populations (Edwards and Schwartz, 1981; MacMahon, 1982; Hayward et al., 1982). We apply the term "catastrophic" to this event because of its intensity and the large area (>600 km2) over which successional processes were initiated. We present here the results of surveys for mammals, particularly small mammals (excluding bats), conducted in the Mount St. Helens region during the 40 months following the eruption. Our purpose was to elucidate any patterns in species representation that might exist along a gradient of disturbance "intensity", and thus document which species could potentially influence early plant successional patterns there. We infer whether individuals captured were more likely to have been residuals (or their descendants), or immigrants from areas less affected by the eruption, from consideration of the time span between the eruption and the capture date, the trapping location, and life history data. We also make inferences concerning the animal-environment relationships that led to our survey results, and thereby address the question of the likelihood of other types of disturbance, either natural or anthropogenic, producing similar results. Data concerning survival of Thomomys talpoides, the northern pocket gopher, have been presented elsewhere (Andersen, 1982). Initial results from our studies of the relationships among residual small mammals and plant population dynamics are detailed in MacMahon and Warner (1984), Allen et al. (1984) and Andersen and MacMahon (in press).

  20. Catalog of Mount St. Helens 2004-2007 Dome Samples with Major- and Trace-Element Chemistry

    USGS Publications Warehouse

    Thornber, Carl R.; Pallister, John S.; Rowe, Michael C.; McConnell, Siobhan; Herriott, Trystan M.; Eckberg, Alison; Stokes, Winston C.; Cornelius, Diane Johnson; Conrey, Richard M.; Hannah, Tammy; Taggart, Joseph E.; Adams, Monique; Lamothe, Paul J.; Budahn, James R.; Knaack, Charles M.

    2008-01-01

    Sampling and analysis of eruptive products at Mount St. Helens is an integral part of volcano monitoring efforts conducted by the U.S. Geological Survey?s Cascades Volcano Observatory (CVO). The objective of our eruption sampling program is to enable petrological assessments of pre-eruptive magmatic conditions, critical for ascertaining mechanisms for eruption triggering and forecasting potential changes in eruption behavior. This report provides a catalog of near-vent lithic debris and new dome-lava collected during 34 intra-crater sampling forays throughout the October 2004 to October 2007 (2004?7) eruptive interval at Mount St. Helens. In addition, we present comprehensive bulk-rock geochemistry for a time-series of representative (2004?7) eruption products. This data, along with that in a companion report on Mount St. Helens 2004 to 2006 tephra by Rowe and others (2008), are presented in support of the contents of the U.S. Geological Survey Professional Paper 1750 (Sherrod and others, eds., 2008). Readers are referred to appropriate chapters in USGS Professional Paper 1750 for detailed narratives of eruptive activity during this time period and for interpretations of sample characteristics and geochemical data. The suite of rock samples related to the 2004?7 eruption of Mount St. Helens and presented in this catalog are archived at the David A. Johnson Cascades Volcano Observatory, Vancouver, Wash. The Mount St. Helens 2004?7 Dome Sample Catalogue with major- and trace-element geochemistry is tabulated in 3 worksheets of the accompanying Microsoft Excel file, of2008-1130.xls. Table 1 provides location and sampling information. Table 2 presents sample descriptions. In table 3, bulk-rock major and trace-element geochemistry is listed for 44 eruption-related samples with intra-laboratory replicate analyses of 19 dacite lava samples. A brief overview of the collection methods and lithology of dome samples is given below as an aid to deciphering the dome sample

  1. Seismicity and infrasound associated with explosions at Mount St. Helens, 2004-2005: Chapter 6 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

    USGS Publications Warehouse

    Moran, Seth C.; McChesney, Patrick J.; Lockhart, Andrew B.

    2008-01-01

    Six explosions occurred during 2004-5 in association with renewed eruptive activity at Mount St. Helens, Washington. Of four explosions in October 2004, none had precursory seismicity and two had explosion-related seismic tremor that marked the end of the explosion. However, seismicity levels dropped following each of the October explosions, providing the primary instrumental means for explosion detection during the initial vent-clearing phase. In contrast, explosions on January 16 and March 8, 2005, produced noticeable seismicity in the form of explosion-related tremor, infrasonic signals, and, in the case of the March 8 explosion, an increase in event size ~2 hours before the explosion. In both 2005 cases seismic tremor appeared before any infrasonic signals and was best recorded on stations located within the crater. These explosions demonstrated that reliable explosion detection at volcanoes like Mount St. Helens requires seismic stations within 1-2 km of the vent and stations with multiple acoustic sensors.

  2. Petrology of the 2004-2006 Mount St. Helens lava dome -- implications for magmatic plumbing and eruption triggering: Chapter 30 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

    USGS Publications Warehouse

    Pallister, John S.; Thornber, Carl R.; Cashman, Katharine V.; Clynne, Michael A.; Lowers, Heather; Mandeville, Charles W.; Brownfield, Isabelle K.; Meeker, Gregory P.; Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

    2008-01-01

    The question of new versus residual magma has implications for the long-term eruptive behavior of Mount St. Helens, because arrival of a new batch of dacitic magma from the deep crust could herald the beginning of a new long-term cycle of eruptive activity. It is also important to our understanding of what triggered the eruption and its future course. Two hypotheses for triggering are considered: (1) top-down fracturing related to the

  3. Multiphase-flow numerical modeling of the 18 May 1980 lateral blast at Mount St. Helens, USA

    USGS Publications Warehouse

    Ongaro, T.E.; Widiwijayanti, C.; Clarke, A.B.; Voight, B.; Neri, A.

    2011-01-01

    Volcanic lateral blasts are among the most spectacular and devastating of natural phenomena, but their dynamics are still poorly understood. Here we investigate the best documented and most controversial blast at Mount St. Helens (Washington State, United States), on 18 May 1980. By means of three-dimensional multiphase numerical simulations we demonstrate that the blast front propagation, fi nal runout, and damage can be explained by the emplacement of an unsteady, stratifi ed pyroclastic density current, controlled by gravity and terrain morphology. Such an interpretation is quantitatively supported by large-scale observations at Mount St. Helens and will infl uence the defi nition and predictive mapping of hazards on blast-dangerous volcanoes worldwide. ?? 2011 Geological Society of America.

  4. Petrology and geochemistry of high cascade volcanics in southern Washington: Mount St. Helens volcano and the Indian Heaven basalt field

    SciTech Connect

    Smith, D.R.

    1984-01-01

    Mount St. Helens volcano (Washington, USA) has been characterized by four eruptive periods during the last 2200 years. Eruptive products include a wide spectrum of rock types including basaltic to andesitic lavas, andesitic to dacitic pyroclastic flows and tephra, and dacite domes. The major and trace element compositions of some andesites and dacites are broadly consistent with their derivation from a basaltic andesite parental magma by fractional cyrstallization processes involving the observed phenocryst assemblages. However, the strontium and oxygen isotopic compositions of representative samples of the Mount St. Helens suite indicate that closed system processes cannot explain the isotopic variations. The isotopic rations are positively correlated with one another and the bulk composition (SiO/sub 2/, Mg number, etc.). The vents of the nearby Indian Heaven Quaternary volcanic field erupted several basalt types which can be defined on the basis of major and trace element composition - calcalkaline (low and high TiO/sub 2/ varieties), transitional, and tholeiitic. Several of these basalt types occur at Mount St. Helens as well, but Indian Heaven lavas are generally more primitive as indicated by higher Mg/(Mg + Fe) ratios. The distribution of volcanic rock types in relation to local structures in the Cascade Range of southern Washington and northern Oregon suggests that crustal structure may influence the degree of evolution of specific volcanic fields. Cascade arc suggests that volcanic arc magma evolution does not necessarily produce a continuous sequence from tholeiitic to calcalkaline rocks in time or space.

  5. Total sulfur dioxide emissions and pre-eruption vapor-saturated magma at Mount St. Helens, 1980-88

    NASA Astrophysics Data System (ADS)

    Gerlach, T. M.; McGee, K. A.

    1994-12-01

    SO2 from explosive volcanism can cause significant climatic and atmospheric impacts, but the source of the sulfur is controversial. Total ozone mapping spectrometer (TOMS), correlation spectrometer (COSPEC), and ash leachate data for Mount St. Helens from the time of the climactic eruption on 18 May 1980 to the final stages of non-explosive degassing in 1988 give a total SO2 emission of 2 Mt. COSPEC data show a sharp drop in emission rate that was apparently controlled by a decreasing rate of magma supply. A total SO2 emission of only 0.08 Mt is estimated from melt inclusion data and the conventional assumption that the main sulfur source was pre-eruption melt; commonly invoked sources of 'excess sulfur' (anhydrite decomposition, basaltic magma, and degassing of non-erupted magma) are unlikely in this case. Thus melt inclusions may significantly underestimate SO2 emissions and impacts of explosive volcanism on climate and the atmosphere. Measured CO2 emissions, together with the H2O content of melt inclusions and experimental solubility data, indicate the Mount St. Helens dacite was vapor-saturated at depth prior to ascent and suggest that a vapor phase was the main source of sulfur for the 2-Mt of SO2. A vapor source is consistent with experimental studies on the Mount St. Helens dacite and removes the need for a much debated shallow magma body.

  6. Geologic Map of the Saint Helens Quadrangle, Columbia County, Oregon, and Clark and Cowlitz Counties, Washington

    USGS Publications Warehouse

    Evarts, Russell C.

    2004-01-01

    The Saint Helens 7.5' quadrangle is situated in the Puget-Willamette Lowland approximately 35 km north Portland, Oregon. The lowland, which extends from Puget Sound into west-central Oregon, is a complex structural and topographic trough that lies between the Coast Range and the Cascade Range. Since late Eocene time, Cascade Range has been the locus of a discontinuously active volcanic arc associated with underthrusting of oceanic lithosphere beneath the North American continent along the Cascadia Subduction Zone. The Coast Range occupies the forearc position within the Cascadia arc-trench system and consists of a complex assemblage of Eocene to Miocene volcanic and marine sedimentary rocks. The Saint Helens quadrangle lies in the northern part of the Portland Basin, a roughly 2000-km2 topographic and structural depression. It is the northernmost of several sediment-filled structural basins that collectively constitute the Willamette Valley segment of the Puget-Willamette Lowland (Beeson and others, 1989; Swanson and others, 1993; Yeats and others, 1996). The rhomboidal basin is approximately 70 km long and 30 km wide, with its long dimension oriented northwest. The Columbia River flows west and north through the Portland Basin at an elevation near sea level and exits through a confined bedrock valley less than 2.5 km wide about 16 km north of Saint Helens. The flanks of the basin consist of Eocene through Miocene volcanic and sedimentary rocks that rise to elevations exceeding 2000 ft (610 m). Seismic-reflection profiles (L.M. Liberty, written commun., 2003) and lithologic logs of water wells (Swanson and others, 1993; Mabey and Madin, 1995) indicate that as much as 550 m of late Miocene and younger sediments have accumulated in the deepest part of the basin near Vancouver. Most of this basin-fill material was carried in from the east by the Columbia River but contributions from streams draining the adjacent highlands are locally important. The Portland Basin has

  7. Mount Saint Helens, Washington, USA, SRTM Perspective: Shaded Relief and Colored Height

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Mount Saint Helens is a prime example of how Earth's topographic form can greatly change even within our lifetimes. The mountain is one of several prominent volcanoes of the Cascade Range that stretches from British Columbia, Canada, southward through Washington, Oregon, and into northern California. Mount Adams (left background) and Mount Hood (right background) are also seen in this view, which was created entirely from elevation data produced by the Shuttle Radar Topography Mission.

    Prior to 1980, Mount Saint Helens had a shape roughly similar to other Cascade peaks, a tall, bold, irregular conic form that rose to 2950 meters (9677 feet). However, the explosive eruption of May 18, 1980, caused the upper 400 meters (1300 feet) of the mountain to collapse, slide, and spread northward, covering much of the adjacent terrain (lower left), leaving a crater atop the greatly shortened mountain. Subsequent eruptions built a volcanic dome within the crater, and the high rainfall of this area lead to substantial erosion of the poorly consolidated landslide material.

    Eruptions at Mount Saint Helens subsided in 1986, but renewed volcanic activity here and at other Cascade volcanoes is inevitable. Predicting such eruptions still presents challenges, but migration of magma within these volcanoes often produces distinctive seismic activity and minor but measurable topographic changes that can give warning of a potential eruption.

    Three visualization methods were combined to produce this image: shading of topographic slopes, color coding of topographic height, and then projection into a perspective view. The shade image was derived by computing topographic slope in the northeast-southwest (left to right) direction, so that northeast slopes appear bright and southwest slopes appear dark. Color coding is directly related to topographic height, with green at the lower elevations, rising through yellow and tan, to white at the highest elevations. The perspective

  8. Environmental Impact of the Helen, Research, and Chicago Mercury Mines on Water, Sediment, and Biota in the Upper Dry Creek Watershed, Lake County, California

    USGS Publications Warehouse

    Rytuba, James J.; Hothem, Roger L.; May, Jason T.; Kim, Christopher S.; Lawler, David; Goldstein, Daniel; Brussee, Brianne E.

    2009-01-01

    The Helen, Research, and Chicago mercury (Hg) deposits are among the youngest Hg deposits in the Coast Range Hg mineral belt and are located in the southwestern part of the Clear Lake volcanic field in Lake County, California. The mine workings and tailings are located in the headwaters of Dry Creek. The Helen Hg mine is the largest mine in the watershed having produced about 7,600 flasks of Hg. The Chicago and Research Hg mines produced only a small amount of Hg, less than 30 flasks. Waste rock and tailings have eroded from the mines, and mine drainage from the Helen and Research mines contributes Hg-enriched mine wastes to the headwaters of Dry Creek and contaminate the creek further downstream. The mines are located on federal land managed by the U.S. Bureau of Land Management (USBLM). The USBLM requested that the U.S. Geological Survey (USGS) measure and characterize Hg and geochemical constituents in tailings, sediment, water, and biota at the Helen, Research, and Chicago mines and in Dry Creek. This report is made in response to the USBLM request to conduct a Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA - Removal Site Investigation (RSI). The RSI applies to removal of Hg-contaminated mine waste from the Helen, Research, and Chicago mines as a means of reducing Hg transport to Dry Creek. This report summarizes data obtained from field sampling of mine tailings, waste rock, sediment, and water at the Helen, Research, and Chicago mines on April 19, 2001, during a storm event. Further sampling of water, sediment, and biota at the Helen mine area and the upper part of Dry Creek was completed on July 15, 2003, during low-flow conditions. Our results permit a preliminary assessment of the mining sources of Hg and associated chemical constituents that could elevate levels of monomethyl Hg (MMeHg) in the water, sediment, and biota that are impacted by historic mining.

  9. Subsurface Imaging at Mount St. Helens with a Large-N Geophone Array

    NASA Astrophysics Data System (ADS)

    Hansen, S. M.; Schmandt, B.; Levander, A.; Kiser, E.; Vidale, J. E.; Moran, S. C.

    2015-12-01

    The 900-instrument Mount St. Helens nodal array recorded continuous data for approximately two weeks in the summer of 2014 and provides a remarkable opportunity to interrogate the structure beneath an active arc volcano. Two separate imaging techniques are applied to constrain both the distribution of microseismicity and subsurface velocity structure. Reverse-time source imaging is applied to the 10 km3 region beneath the volcanic edifice where most of cataloged seismicity occurred during the experiment. These efforts resulted in an order of magnitude increase in earthquake detections over the normal monitoring operations of the Pacific Northwest Seismic Network. Earthquake locations resolve a narrow, ≤1 km wide, vertical lineament of seismicity that extends from the surface to 4 km depth directly beneath the summit crater, consistent with the historical event distribution of Waite and Moran[2009]. This feature is interpreted as a fracture network that acts as a conduit connecting an underlying magma chamber to the surface. Moho imaging is achieved using the near-offset (< 30 km) PmP phase generated by the iMUSH active source shots that occurred during the deployment. The PmP arrivals are enhanced using short-term-average over long-term-average processing and then migrated using a 3D velocity model. The observed Moho depths range from 35-40 km with a slight eastward deepening across the Mt St Helens fracture zone. Significant variations are observed in the Moho reflectivity. Large amplitude PmP energy is observed in shots originating from the north and east whereas shots from the south-west display little-to-no PmP energy. The region above the reflective Moho is approximately coincident with areas displaying reduced lower-crustal velocities in the initial iMUSH tomography models and may therefore contain fluids and/or partial melt. Additional evidence for lower crustal fluids in this region is provided by deep-long-period (DLP) events which have historically been

  10. Rockslide-debris avalanche of May 18, 1980, Mount St. Helens Volcano, Washington

    USGS Publications Warehouse

    Glicken, Harry

    1996-01-01

    This report provides a detailed picture of the rockslide-debris avalanche of the May 18, 1980, eruption of Mount St. Helens volcano. It provides a characterization of the deposit, a reinterpretation of the details of the first minutes of the eruption of May 18, and insight into the transport mechanism of the mass movement. Details of the rockslide event, as revealed by eyewitness photographs, are correlated with features of the deposit. The photographs show three slide blocks in the rockslide movement. Slide block I was triggered by a magnitude 5.1 earthquake at 8:32 a.m. Pacific Daylight Time (P.D.T.). An exploding cryptodome burst through slide block II to produce the 'blast surge.' Slide block III consisted of many discrete failures that were carried out in continuing pyroclastic currents generated from the exploding cryptodome. The cryptodome continued to depressurize after slide block III, producing a blast deposit that rests on top of the debris-avalanche deposit. The hummocky 2.5 cubic kilometer debris-avalanche deposit consists of block facies (pieces of the pre-eruption Mount St. Helens transported relatively intact) and matrix facies (a mixture of rocks from the old mountain and cryptodome dacite). Block facies is divided into five lithologic units. Matrix facies was derived from the explosively generated current of slide block III as well as from disaggregation and mixing of debris-avalanche blocks. The mean density of the old cone was measured to be abut 20 percent greater than the mean density of the avalanche deposit. Density in the deposit does not decrease with distance which suggests that debris-avalanche blocks were dilated at the mountain, rather than during transport. Various grain-size parameters that show that clast size converges about a mean with distance suggest mixing during transport. The debris-avalanche flow can be considered a grain flow, where particles -- either debris-avalanche blocks or the clasts within the blocks -- collided and

  11. Leaching characteristics of ash from the May 18, 1980, eruption of Mount St. Helens Volcano, Washington

    USGS Publications Warehouse

    Smith, David Burl; Zielinski, Robert A.; Taylor, Howard Edward

    1982-01-01

    Leaching of freshly erupted air-fall ash, unaffected by rain, from the May 18, 1.980,eruption of Mount St. Helens volcano, Washington, shows that Ca 2+, Na+, Mg+, SO4 2-, and Cl- are the predominant chemical species released on first exposure of the ash to water. Extremely high correlation of Ca with SO4 and Na with Cl in water leachates suggests the presence of CaSO4 and NaCl salts on the ash. The amount of water soluble material on ash increases with distance from source and with the weight fraction of small (less than 63 micrometers) ash particles of high-surface area. This suggests that surface reactions such as adsorption are responsible for concentrating the soluble material. CaSO4, NaCl, and other salts are probably formed as microscopic crystals in the high-temperature core of the eruption column and are then adsorbed by silicate ash particles. The environmentally important elements Zn, Cu, Cd, F, Pb, and Ba are released by a water leach in concentrations which could pose short-term hazards to some forms of aquatic life. However, calculated concentrations are based on a water-to-ash ratio of 4:1 or less, which is probably an underestimation of the regionally operative ratio. A subsequent leach of ash by warm alkaline solution shows dramatic increases in the amount of dissolved SiO2, U, and V, which are probably caused by increased dissolution of the glassy component of ash. Glass dissolution by alkaline ground water is a mechanism for providing these three elements to sedimentary traps where they may co-accumulate as uraniferous silica or U-V minerals. Leaching characteristics of ash from Mount St. Helens are comparable to characteristics of ash of similar composition from volcanoes in Guatemala. Ashes from each locality show similar ions predominating for a given leachate and similar fractions of a particular element in the ash removed on contact with the leach solution.

  12. Completion of the 16 station Plate Boundary Observatory (PBO) network on Mt. St. Helens, WA

    NASA Astrophysics Data System (ADS)

    Austin, K.; Hafner, K.; Fengler, K.; Doelger, S.

    2006-12-01

    The Plate Boundary Observatory (PBO), part of the larger NSF-funded EarthScope project, is completing year 3 of the installation phase of 852 continuously operating GPS stations in the Western United States. Some of these GPS stations are focused specifically on centers of volcanic activity. Mt. St. Helens is one of these volcanic areas of interest in the Pacific Northwest (PNW) region. The PNW region will complete the installation of a 16 station GPS network on Mt. St. Helens during September 2006. This work also includes the co-location and installation of tiltmeters at four of the existing GPS sites. Network upgrades will be completed to handle the increase in data flow from the new GPS stations as well as the data from the tiltmeters and strainmeters. New GPS site installations include six helicopter accessible sites, and three drive to sites on the south flank of the mountain. Higher elevation sites will be outfitted with an eight battery, three solar panel power array to keep the stations operational during winter months. The remaining sites use a four battery, three solar panel array that has proved sufficient at other GPS locations over the past 2 winters. All stations will communicate via one of 2 radio networks set up on the mountain. The northern radio network transmits data for ten stations through a microwave connection at the Johnston Ridge observatory that also provides communications for PBO strainmeter, tiltmeter and CVO equipment. The remaining 10 stations on the south side of the mountain, are relayed through a hub at Washington State University's Vancouver Campus that is also providing data services for CVO. Results from analysis of data from both PBO and USGS GPS stations on the mountain, show a radially inward and downward motion, with the maximum vertical offsets high on the mountain and the maximum horizontal offsets located at distances of 5-10km from the crater. Displacements are small over the 2004-present eruption with a maximum of 3cm

  13. Investigating microseismicity and crustal structure beneath Mount St. Helens with a 900-geophone array

    NASA Astrophysics Data System (ADS)

    Schmandt, B.; Hansen, S. M.; Kiser, E.; Levander, A.; Wang, Y.; Lin, F. C.

    2015-12-01

    During Summer 2014 we deployed ~900 cable-free seismographs within ~12 km of Mount St. Helens. Each seismograph contained a 10-Hz geophone and recorded continuously for two weeks with a sample rate of 250 Hz. The array temporarily provides a major increase in spatial coverage compared to the 10-station long-term monitoring array, but each of the geophone has a high noise floor compared to the force-feedback sensors of the long-term array that is part of the Pacific Northwest Seismic Network (PNSN). We are investigating the utility of the geophone array for source and structural analyses using ambient noise, high-frequency microseismicity, deep long-period seismicity, and 23 controlled sources from the concurrent iMUSH active source project. Surface waves extracted from ambient noise cross-correlation have adequate signal to noise ratios for upper crustal tomography using frequencies ~0.2-0.5 Hz. Efforts to extract higher frequency body waves with interferometry are ongoing and include focusing on time periods with stronger high frequency noise or coda from controlled sources and earthquakes. Continuous back-projection of the array data into the 3-D subsurface was used to automatically detect and locate high-frequency (>5 Hz) microseismicity extending down to ~M-2, with a completeness magnitude of ~0.3. Two deep crustal low frequency earthquakes (<5 Hz) detected by PNSN occurred during our survey. We relocated these events and are using them to optimize back-projection parameters and create matched filters to search for additional deep low frequency seismicity. One of the deep low frequency events locates at approximately Moho depth using back-projection of S-wave energy and S-P times from dense geophone sub-arrays. This event occurs just southeast of Mount St. Helens in an area where controlled source refraction tomography images anomalously slow lower crust and common midpoint stacking images a bright Moho indicative of a locally high impedance contrast between

  14. Effects of lava-dome emplacement on the Mount St. Helens crater glacier

    NASA Astrophysics Data System (ADS)

    Walder, J. S.; Schilling, S. P.; Denlinger, R. P.; Vallance, J. W.

    2004-12-01

    Since the end of the 1981-1986 episode of lava-dome growth at Mount St. Helens, an unusual glacier has grown rapidly within the crater of the volcano. The glacier, which is fed primarily by avalanching from the crater walls, contains about 30% rock debris by volume, has a maximum thickness of about 220 m and a volume of about 120 million cubic m, and forms a crescent that wraps around the old lava dome on both east and west sides. The new (October 2004) lava dome in the south of the crater began to grow centered roughly on the contact between the old lava dome and the glacier, in the process uplifting both ice and old dome rock. As the new dome is spreading to the south, the adjacent glacier is bulging upward. Firn layers on the outer flank of the glacier bulge have been warped upward almost vertically. In contrast, ice adjacent to the new dome has been thoroughly fractured. The overall style of deformation is reminiscent of that associated with salt-dome intrusion. Drawing an analogy to sand-box experiments, we suggest that the glacier is being deformed by high-angle reverse faults propagating upward from depth. Comparison of Lidar images of the glacier from September 2003 and October 2004 reveals not only the volcanogenic bulge but also elevated domains associated with the passage of kinematic waves, which are caused by glacier-mass-balance perturbations and have nothing to do with volcanic activity. As of 25 October 2004, growth of the new lava dome has had negligible hydrological consequences. Ice-surface cauldrons are common consequences of intense melting caused by either subglacial eruptions (as in Iceland) or subglacial venting of hot gases (as presently taking place at Mount Spurr, Alaska). However, there has been a notable absence of ice-surface cauldrons in the Mount St. Helens crater glacier, aside from a short-lived pond formed where the 1 October eruption pierced the glacier. We suggest that heat transfer to the glacier base is inefficient because

  15. Magma reservoirs from the upper crust to the Moho inferred from high-resolution Vp and Vs models beneath Mount St. Helens, Cascades, USA

    NASA Astrophysics Data System (ADS)

    Kiser, Eric; Levander, Alan; Zelt, Colin; Palomeras, Imma; Schmandt, Brandon; Hansen, Steven; Creager, Kenneth; Ulberg, Carl

    2016-04-01

    Mount St. Helens is currently the most active volcano along the Cascadia arc. Though several studies investigated the magmatic system beneath Mount St. Helens following the May 18, 1980 eruption, tomographic imaging of the system has been limited to ~10 km depth due to the distribution of earthquakes in the region. This has made it difficult to estimate the volume of the shallow magma reservoir beneath the volcano, the regions of magma entry into the lower crust, and the connectivity of this magma system throughout the crust. The latter is particularly interesting as one interpretation of the Southern Washington Cascades Conductor (SWCC) suggests that the Mount St Helens and Mount Adams volcanic systems are connected in the middle crust (Hill et al., 2009). The multi-disciplinary iMUSH (imaging Magma Under St. Helens) project is designed to investigate these and other fundamental questions associated with Mount St. Helens. Here we present the first high-resolution 2D Vp and Vs models derived from travel-time data from the iMUSH 3D active-source seismic experiment. The experiment consisted of ~6000 seismograph stations which recorded 23 explosions and hundreds of local earthquakes. Directly beneath Mount St. Helens, we observe a high Vp/Vs body, inferred to be the upper/middle crustal magma reservoir, between 4 and 13 km depth. We observe a second high Vp/Vs body, likely of magmatic origin, at roughly the same depth beneath Indian Heaven Volcanic Field, which last erupted 9 ka. Southeast of Mount St. Helens is a low Vp column extending from the middle crust, ~15 km depth, to the Moho at ~40 km depth. A cluster of deep long-period events, typically associated with injection of magma, occurs at the northwestern boundary of this low Vp column. We interpret this as the middle-lower crust magma reservoir. In the lower crust, high Vp features bound the magma reservoir directly beneath Mount St. Helens and the Indian Heaven Volcanic Field. One explanation for these high Vp

  16. Toxicity of Mount St. Helens ash leachate to a blue-green alga

    USGS Publications Warehouse

    McKnight, Diane M.; Feder, Gerald L.; Stiles, Eric A.

    1981-01-01

    During several periods of volcanic-ash eruption at Mount St. Helens, Wash., (March 30, May 25-26, May 30-June 2, and June 12-13, 1980) strong winds from the north occurred at high altitudes. As a result, the volcanic ash fell some 50 miles to the south in the Bull Run watershed, the principal water-supply source for the metropolitan area of Portland, Oreg. Water samples collected from three stream sites within the watershed were compared with samples collected during the same season in previous years. No detectable changes were noted in chemical characteristics. Precipitation samples collected immediately after the June 12-13 ash fall ranged in specific conductance from 20 to 41 micromhos per centimeter at 25C and in pH from 4.0 to 4.3 pH units. Stream samples collected during the May-June period ranged in specific conductance from 18 to 28 micromhos per centimeter at 25C and in pH from 6.7 to 7.5 pH units. Volcanic-ash samples were collected and analyzed for particle size, chemical composition, and weight. Significant differences in particle size of ash were found in samples from two separate eruptions. (USGS)

  17. Mount St. Helens Quick Response Damage Assessment Using High-Altitude Infrared Photography

    NASA Astrophysics Data System (ADS)

    Hinkle, Richard E.; Prill, James C.; Pruitt, John R.

    1981-11-01

    After the destructive volcanic eruption of Mount St. Helens on May 18, 1980, there was a need for a quick response damage assessment. Timeliness of the information was emphasized because of the need to immediately devise land man-agement plans for timber sale operations, rehabilitation efforts, fire protection activities, and areas to be preserved. High-altitude color-infrared photography was collected during May and June by the National Aeronautics and Space Administra-tion (NASA) Ames Research Center (ARC). Interpretation of the photography plus a helicopter trip into the area provided the basis for the construction of 58 map-registered overlays within a 3-week period. These overlays depicted in detail the damage to timber resources, the transportation network, and the watershed. Using the 14 timber loss overlays, U.S. Department of Agriculture (USDA) Forest Service personnel were able to digitize cells depicting ownership, degree of damage, and the preeruption cover classes. These digitized data provided such informa-tion as the total area affected within and outside the national forest, total timber acreage destroyed and damaged, the sizes of timber destroyed, and the acreage of barren land both before and after the eruption. The hydrology and transportation overlays provided information for an alert system to locate areas needing in-depth studies. These problem areas were then studied in detail on low-altitude color photography so that potential erosion sites could receive preventive treatments and essential access roads needed for fire control and timber salvage could be repaired.

  18. Changes in the organic material in lakes in the blast zone of Mount St. Helens, Washington

    USGS Publications Warehouse

    McKnight, Diane M.; Klein, John M.; Wissmar, Robert C.

    1984-01-01

    During several periods of volcanic-ash eruption at Mount St. Helens, Wash., (March 30, May 25-26, May 30-June 2, and June 12-13, 1980) strong winds from the north occurred at high altitudes. As a result, the volcanic ash fell some 50 miles to the south in the Bull Run watershed, the principal water-supply source for the metropolitan area of Portland, Oreg. Water samples collected from three stream sites within the watershed were compared with samples collected during the same season in previous years. No detectable changes were noted in chemical characteristics. Precipitation samples collected immediately after the June 12-13 ash fall ranged in specific conductance from 20 to 41 micromhos per centimeter at 25C and in pH from 4.0 to 4.3 pH units. Stream samples collected during the May-June period ranged in specific conductance from 18 to 28 micromhos per centimeter at 25C and in pH from 6.7 to 7.5 pH units. Volcanic-ash samples were collected and analyzed for particle size, chemical composition, and weight. Significant differences in particle size of ash were found in samples from two separate eruptions. (USGS)

  19. Erosional furrows formed during the lateral blast at Mount St. Helens, May 18, 1980

    USGS Publications Warehouse

    Kieffer, S.W.; Sturtevant, B.

    1988-01-01

    Nearly horizontal, quasi-periodic erosional features of 7-m average transverse wavelength and of order 100-m length occur in scattered locations from 3.5 to 9 km from the crater at Mount St. Helens under deposits of the lateral blast of May 18, 1980. We attribute the erosional features to scouring by longitudinal vortices resulting from flow instabilities induced by complex topography, namely, by streamline curvature in regions of reattachment downstream of sheltered regions, and by the cross-flow component of flow subparallel to ridge crests. The diameter of the vortices and their transverse spacing, inferred from the distance between furrows, are taken to be of the order of the boundary layer thickness. The inferred boundary layer thickness (???14 m at 9 km from the source of the blast) is consistent with the running length from the mountain to the furrow locations. The orientation of furrows induced by the cross-flow instability can be used to measure the upwash angle and estimate the flow Mach number: at the central ridge of Spirit Lake the Mach number is inferred to have been about 2.5, and the flow velocity approximately 235 m/s. -from Authors

  20. GOES weather satellite observations and measurements of the May 18, 1980, Mount St. Helens eruption

    NASA Technical Reports Server (NTRS)

    Holasek, R. E.; Self, S.

    1995-01-01

    We demonstrate the use of Geostationary Operational Environmental Satellite (GOES) images of the May 18, 1980, Mount St. Helens volcanic plume in providing details of the dynamics and changing character of this major explosive eruption. Visible and thermal infrared (IR) data from a sequence of images at 30-min intervals from 0850 to 1720 Local Time (LT) give information on dispersal and plume top temperature. Initial visible and IR images at 0850 show the top of a spreading co-ignimbrite-like umbrella plume and an overshooting column emerging from it, both rising off the ground-hugging pyroclastic gravity flow generated by the opening directed blast. The overshooting column had a minimum temperature significantly colder than local ambient atmosphere, indicating substantial undercooling, and a maximum altitude of 31 +/- 2 km at 0920. This large plume system then formed a high-velocity, radially spreading, gravitationally driven current before becoming advected in the wind field at an average downwind velocity of 29 m/s. Reflectance values from visible GOES data change from lower to higher during periods of transition from darker toned Plinian to lighter toned co-ignimbrite plumes indicating that in this case satellite data resolved changes in eruptive style from plumes with a coarser to a finer dominant particle size.

  1. Bimodal Density Distribution of Cryptodome Dacite from the 1980 Eruption of Mount St. Helens, Washington

    USGS Publications Warehouse

    Hoblitt, R.P.; Harmon, R.S.

    1993-01-01

    The explosion of a cryptodome at Mount St. Helens in 1980 produced two juvenile rock types that are derived from the same source magma. Their differences-color, texture and density-are due only to vesicularity differences. The vesicular gray dacite comprises bout 72% of the juvenile material; the black dacite comprises the other 28%. The density of juvenile dacite is bimodally distributed, with peaks at 1.6 g cm-3 (gray dacite) and 2.3 g cm-3 (black dacite). Water contents, deuterium abundances, and the relationship of petrographic structures to vapor-phase crystals indicate both rock types underwent pre-explosion subsurface vesiculation and degassing. The gray dacite underwent a second vesiculation event, probably during the 18 May explosion. In the subsurface, gases probably escaped through interconnected vesicles into the permeable volcanic edifice. We suggest that nonuniform degassing of an initially homogeneous magma produced volatile gradients in the cryptodome and that these gradients were responsible for the density bimodality. That is, water contents less than about 0.2-0.4 wt% produced vesicle growth rates that were slow in comparison to the pyroclast cooling rates; greater water contents produced vesicle growth rates that were fast in comparison to cooling rates. In this scheme, the dacite densities are bimodally distributed simply because, following decompression on 18 May 1980, one clast population vesiculated while the other did not. For clasts that did vesiculate, vesicle growth continued until it was arrested by fragmentation. ?? 1993 Springer-Verlag.

  2. Precursor gases of aerosols in the Mount St. Helens eruption plumes at stratospheric altitudes

    NASA Technical Reports Server (NTRS)

    Inn, E. C. Y.; Vedder, J. F.; Condon, E. P.; Ohara, D.

    1982-01-01

    Nineteen stratospheric samples from the eruption plumes of Mount St. Helens were collected in five flight experiments. The plume samples were collected at various altitudes from 13.1 to 20.7 km by using the Ames cryogenic sampling system on board the NASA U-2 aircraft. The enriched, cryogenically collected samples were analyzed by chromatography. The concentrations of aerosols precursor gases (OCS, SO2, and CS2), CH3Cl, N2O, CF2Cl2, and CFCl3 were measured by gas chromatography. Large enhancement of the mixing ratio of SO2 and moderate enhancement of CS2 and OCS were found in the plume samples compared with similar measurement under pre-volcanic conditions. A fast decay rate of the SO2 mixing ratio in the plume was observed. Measurement of Cl(-), SO2(2-), and NO3(-) by ion chromatography was also carried out on water solutions prepared from the plume samples. The results obtained with this technique imply large mixing ratios of HCl, (NO + NO2 + HNO3), and SO2, in which these constituents are the respective sources of the anions. Measurement of the Rn222 concentration in the plume was made. Other stratospheric constituents in the plume samples, such as H2O, CO2, CH4, and CO, were also observed.

  3. Comparative in vitro cytotoxicity of volcanic ashes from Mount St. Helens, El Chichon, and Galunggung.

    PubMed

    Vallyathan, V; Robinson, V; Reasor, M; Stettler, L; Bernstein, R

    1984-01-01

    Dry sedimented volcanic ash samples from each of three widely separated volcanoes of the "Circum Pacific" region have been subjected to mineralogic analysis and in vitro tests for cytotoxicity. The ash samples from the three different volcanoes varied in particle size, surface area, and concentration of silica. Total crystalline silica in the respirable fraction of ashes was 1.5% (Mount St. Helens, Moses Lake); 1.36% (Galunggung, Bandung-1); 1.95% (Gallunggung, Bandung-2); and 1.72% (El Chichon, Tuxtla). Hemolysis as an index of cytotoxicity was measured by in vitro tests on sheep blood erythrocytes and indicated wide differences in hemolytic activity among ash samples. Alveolar macrophage cytosolic (lactate dehydrogenase) and lysosomal (beta-glucuronidase and beta-N-acetyl glucosaminidase) enzymes were measured as an index of cellular integrity following dust exposure. Hemolysis and release of enzymes from alveolar macrophages were greater with volcanic ash from Galunggung (Bandung-1) and El Chichon (Tuxtla) than the other ashes. Although crystalline silica induced an effect similar to volcanic ash from Galunggung (Bandung-1) on the release of enzymes from alveolar macrophages, the hemolytic potency of silica was much greater. Light and electron microscopic observations of dust-exposed alveolar macrophages indicated that the ash particles were readily phagocytized. These results indicate that volcanic ash is moderately cytotoxic and that exposure may lead to overt reactions and the exacerbation of preexisting chronic inflammatory processes. PMID:6097694

  4. The pulmonary toxicity of an ash sample from the MT. St. Helens Volcano.

    PubMed

    Beck, B D; Brain, J D; Bohannon, D E

    1981-11-01

    Volcanic ash was collected from the Moses Lake region of Washington State after the 18 May 1980 eruption of Mt. St. Helens. The ash was tested in a short-term bioassay system using hamsters exposed by intratracheal instillation. One day after exposure the lungs were lavaged and the fluid collected was characterized using several parameters that represent different manifestations of lung injury: (a) in situ phagocytic ability of pulmonary macrophages; (b) the inflammatory response, as shown by polymorphonuclear neutrophil numbers and albumin levels in lung lavage fluid; and (c) release of cytoplasmic and lysosomal enzymes into the cell-free supernatant of lung-lavage fluid. The response to volcanic ash was elevated compared to controls, but was similar to the response to Al2O3, a dust considered to be relatively inert. In contrast, the response to alpha-quartz, a highly toxic fibrogenic dust, was significantly greater than the response to either volcanic ash or Al2O3 for most parameters measured. PMID:7318780

  5. The pulmonary toxicity of an ash sample from the Mt. St. Helens Volcano

    SciTech Connect

    Beck, B.D.; Brain, J.D.; Bohannon, D.E.

    1981-11-01

    Volcanic ash was collected from the Moses Lake region of Washington State after the 18 May 1980 eruption of Mt. St. Helens. The ash was tested in a short-term bioassay system using hamsters exposed by intratracheal instillation. One day after exposure the lungs were lavaged and the fluid collected was characterized using several parameters that represent different manifestations of lung injury: (a) in situ phagocytic ability of pulmonary macrophages; (b) the inflammatory response, as shown by polymorphonuclear neutrophil numbers and albumin levels in lung lavage fluid; and (c) release of cytoplasmic and lysosomal enzymes into the cell-free supernatant of lung-lavage fluid. The response to volcanic ash was elevated compared to controls, but was similar to the response to Al2O3, a dust considered to be relatively inert. In contrast, the response to alpha-quartz, a highly toxic fibrogenic dust, was significantly greater than the response to either volcanic ash or Al2O3 for most parameters measured.

  6. Erosion by flowing lava: Geochemical evidence in the Cave Basalt, Mount St. Helens, Washington

    USGS Publications Warehouse

    Williams, D.A.; Kadel, S.D.; Greeley, R.; Lesher, C.M.; Clynne, M.A.

    2004-01-01

    We sampled basaltic lava flows and underlying dacitic tuff deposits in or near lava tubes of the Cave Basalt, Mount St. Helens, Washington to determine whether the Cave Basalt lavas contain geochemical evidence of substrate contamination by lava erosion. The samples were analyzed using a combination of wavelength-dispersive X-ray fluorescence spectrometry and inductively-coupled plasma mass spectrometry. The results indicate that the oldest, outer lava tube linings in direct contact with the dacitic substrate are contaminated, whereas the younger, inner lava tube linings are uncontaminated and apparently either more evolved or enriched in residual liquid. The most heavily contaminated lavas occur closer to the vent and in steeper parts of the tube system, and the amount of contamination decreases with increasing distance downstream. These results suggest that erosion by lava and contamination were limited to only the initially emplaced flows and that erosion was localized and enhanced by vigorous laminar flow over steeper slopes. After cooling, the initial Cave Basalt lava flows formed an insulating lining within the tubes that prevented further erosion by later flows. This interpretation is consistent with models of lava erosion that predict higher erosion rates closer to sources and over steeper slopes. A greater abundance of xenoliths and xenocrysts relative to xenomelts in hand samples indicates that mechanical erosion rather than thermal erosion was the dominant erosional process in the Cave Basalt, but further sampling and petrographic analyses must be performed to verify this hypothesis. ?? Springer-Verlag 2003.

  7. Recent developments in high altitude aircraft sampling - Mount St. Helens and stratospheric trace gases

    NASA Astrophysics Data System (ADS)

    Leifer, R.; Sommers, K. G.; Guggenheim, S. F.; Fisenne, I.

    1981-02-01

    An ultra-clean, low volume gas sampling system (CLASS), flown aboard a high altitude aircraft (WB-57F), and providing information on stratospheric trace gases is presented. Attention is given to the instrument design and the electronic control design. Since remote operation is mandatory on the WB-57F, a servo pressure transducer, electrical pressure switch for automatic shutdown, and a mechanical safety relief valve were installed on the sampling manifold, indicated on the CLASS flow chart. The electronic control system consists of hermetically sealed solid state timers, relays, and a stepping switch, for controlling the compressor pump and solenoid valves. In designing the automatic control system, vibration, shock, acceleration, extreme low temperature, and aircraft safety were important considerations. CLASS was tested on three separate occasions, and tables of analytical data from these flights are presented. Readiness capability was demonstrated when the Mount St. Helens eruption plume of May 18, 1980, was intercepted, and it was concluded that no large injection of Rn-222 entered the stratosphere or troposphere from the eruption.

  8. Impact of Mount St. Helens Eruption on Bacteriology of Lakes in the Blast Zone

    PubMed Central

    Staley, J. T.; Lehmicke, L. G.; Palmer, F. E.; Peet, R. W.; Wissmar, R. C.

    1982-01-01

    Lakes lying within the blast zone of Mount St. Helens showed dramatic increases in heterotrophic bacterial numbers after the eruption of 18 May 1980. The total microscopic counts of bacteria in some of the most severely affected lakes were more than 107 cells per ml, an order of magnitude above the counts in outlying control lakes. Likewise, the numbers of viable bacteria reached levels of more than 106 cells per ml, compated with fewer than 104 cells per ml in control lakes. The CPS medium used for enumeration provided growth of up to 81.5% of the bacteria during sampling of one of the blast zone lakes. The high numbers of bacteria and the efficacy of the viable enumeration procedure are evidence that the lakes have been transformed rapidly from oligotrophy to eutrophy due to the eruption and its aftermath. Organic material leached from the devastated forest vegetation is thought to be responsible for the enrichment of heterotrophs. Total coliform bacteria were found in all of the blast zone lakes, and some lakes contained fecal coliform bacteria. Klebsiella pneumoniae was the predominant total coliform and was also identified as one of the fecal coliform bacteria, although Escherichia coli was the predominant species in that category. Our data indicate that bacterial populations peaked in the outer blast zone lakes in the summer of 1980 and in most of the inner lakes during the summer of 1981. PMID:16345973

  9. Four-year prospective study of the respiratory effects of volcanic ash from Mt. St. Helens

    SciTech Connect

    Buist, A.S.; Vollmer, W.M.; Johnson, L.R.; Bernstein, R.S.; McCamant, L.E.

    1986-04-01

    This report describes the 4-yr follow-up of 712 loggers exposed over an extended period to varying levels of fresh volcanic ash from the 1980 eruptions of Mt. St. Helens. Concerns related to the irritant effect the ash might have on the airways and also to its fibrogenic potential if exposures were intense and continued over many years. Our subjects were divided into 3 groups: high, low, and no exposure. Baseline testing was begun in June 1980, 1 month after the major eruption, and follow-up testing continued on an annual basis through 1984; 88% of the loggers have been tested at least 3 times. Analysis of lung function data showed that a significant, exposure-related decline in FEV1 occurred during the first year after the eruption. The decline was short-lived, however, and by 1984 the differences between exposure groups were no longer significant. Self-reported symptoms of cough, phlegm, and wheeze showed a similar pattern. No ash-related changes were seen in chest roentgenograms taken in 1980 and in 1984. Our findings are consistent with the hypothesis that the inhaled ash caused mucus hypersecretion and/or airway inflammation that reversed when the exposure levels decreased. The ash levels to which the loggers were exposed were low compared with permissible occupational levels for nuisance dusts, but generally higher than the total suspended particulate levels permissible in ambient air.

  10. Geologic map of the Sasquatch Steps area, north flank of Mount St. Helens, Washington

    USGS Publications Warehouse

    Hausback, Brian P.

    2000-01-01

    The 1980 eruption of Mount St. Helens resulted in both new volcanic deposits and deeply incised exposures into pre-1980 deposits. These exposures were produced by excavation of the crater by the 1980 landslides and lateral explosion as well as the subsequent erosion of Step and Loowit creeks by northerly stream flow out of the horseshoe-shaped crater. The map covers the area known as the Sasquatch Steps (commonly called the Steps), which lies between the Pumice Plain on the north and the lowermost portion of the crater on the south. Rapid alluvial aggradation at the base of the Steps is presently burying some of the lowest exposures, and erosion is stripping many of the upland deposits. The stratigraphic sequence exposed in the map area includes deposits from the eruptive periods listed in table 1 (Crandell, 1987). Assignment of deposits to the various eruptive periods is based on lithology and ferromagnesian-mineral suites typical for each of the eruptive periods (Mullineaux and Crandell, 1981; Mullineaux, 1986), as well as three 14 C dates from wood found in the deposits. Faults displayed on the map are largely confined to the older part of the stratigraphic section. These older units are highly shattered, with an extremely complicated fracture pattern, and it is only possible to show the largest and most distinctive of these structures at the map scale. Interpretation of the stratigraphy and structure of this area is given in Hausback and Swanson (1990).

  11. Ash loading and insolation at Hanford, Washington during and after the eruption of Mount St. Helens

    NASA Technical Reports Server (NTRS)

    Laulainen, N. S.

    1982-01-01

    The effects of volcanic ash suspended in the atmosphere on the incident solar radiation was monitored at the Hanford Meteorological Station (HMS) subsequent to the major eruption of Mount St. Helens on May 18, 1980. Passage of the ash plume over Hanford resulted in a very dramatic decrease of solar radiation intensity to zero. A reduction in visibility to less than 1 km was observed, as great quantities of ash fell out of the plume onto the ground. Ash loading in the atmosphere remained very high for several days following the eruption, primarily as a result of resuspension from the surface. Visibilities remained low (2 to 8 km) during this period. Estimates of atmospheric turbidity were made from the ratio of diffuse-to-direct solar radiation; these turbidities were used to estimate extinction along a horizontal path, a quantity which can be related to visibility. Comparisons of observed and estimated visibilities were very good, in spite of the rather coarse approximations used in the estimates. Atmospheric clarity and visibility improved to near pre-eruption conditions following a period of rain showers. The diffuse-to-direct ratio of solar radiation provided a useful index for estimating volcanic ash loading of the atmosphere.

  12. Digital database of channel cross-section surveys, Mount St. Helens, Washington

    USGS Publications Warehouse

    Mosbrucker, Adam R.; Spicer, Kurt R.; Major, Jon J.; Saunders, Dennis R.; Christianson, Tami S.; Kingsbury, Cole G.

    2015-08-06

    Stream-channel cross-section survey data are a fundamental component to studies of fluvial geomorphology. Such data provide important parameters required by many open-channel flow models, sediment-transport equations, sediment-budget computations, and flood-hazard assessments. At Mount St. Helens, Washington, the long-term response of channels to the May 18, 1980, eruption, which dramatically altered the hydrogeomorphic regime of several drainages, is documented by an exceptional time series of repeat stream-channel cross-section surveys. More than 300 cross sections, most established shortly following the eruption, represent more than 100 kilometers of surveyed topography. Although selected cross sections have been published previously in print form, we present a comprehensive digital database that includes geospatial and tabular data. Furthermore, survey data are referenced to a common geographic projection and to common datums. Database design, maintenance, and data dissemination are accomplished through a geographic information system (GIS) platform, which integrates survey data acquired with theodolite, total station, and global navigation satellite system (GNSS) instrumentation. Users can interactively perform advanced queries and geospatial time-series analysis. An accuracy assessment provides users the ability to quantify uncertainty within these data. At the time of publication, this project is ongoing. Regular database updates are expected; users are advised to confirm they are using the latest version.

  13. Drainage evolution in the debris avalanche deposits near Mount Saint Helens, Washington

    NASA Technical Reports Server (NTRS)

    Beach, G. L.; Dzurisin, D.

    1984-01-01

    The 18 May 1980 eruption of Mount St. Helens was initiated by a massive rockslide-debris avalanche which completely transformed the upper 25 km of the North Fork Toutle River valley. The debris was generated by one of the largest gravitational mass movements ever recorded on Earth. Moving at an average velocity of 35 m/s, the debris avalanche buried approximately 60 sq km of terrain to an average depth of 45 m with unconsolidated, poorly sorted volcaniclastic material, all within a period of 10 minutes. Where exposed and unaltered by subsequent lahars and pyroclastic flows, the new terrain surface was characterized predominantly by hummocks, closed depressions, and the absence of an identifiable channel network. Following emplacement of the debris avalanche, a complex interrelationship of fluvial and mass wasting processes immediately began operating to return the impacted area to an equilibrium status through the removal of material (potential energy) and re-establishment of graded conditions. In an attempt to chronicle the morphologic evolution of this unique environmental setting, a systematic series of interpretative maps of several selected areas was produced. These maps, which document the rate and character of active geomorphic processes, are discussed.

  14. Analysis of seismic body waves excited by the Mount St. Helens eruption of May 18, 1980

    NASA Technical Reports Server (NTRS)

    Kanamori, H.; Given, J. W.; Lay, T.

    1984-01-01

    Seismic body waves which were excited by eruption of Mt. St. Helens, and recorded by the Global Digital Seismographic Network (GDSN) stations are analyzed to determine the nature and the time sequence of the events associated with the eruption. The polarity of teleseismic P waves (period 20 sec) is identical at six stations which are distributed over a wide azimuthal range. This observation, together with a very small S to P amplitude ratio (at 20 sec), suggests that the source is a nearly vertical single force that represents the counter force of the eruption. The time history of the vertical force suggests two distinct groups of events, about two minutes apart, each consisting of several subevents with a duration of about 25 sec. The magnitude of the force is approximately 2.6 to the 17th power dyne. This vertical force is in contrast with the long period (approximately 150 sec) southward horizontal single force which was determined by a previous study and interpreted to be due to the massive landslide. Previously announced in STAR as N83-15968

  15. Analysis of seismic body waves excited by the Mount Saint Helens eruption of May 18, 1980

    NASA Technical Reports Server (NTRS)

    Kanamori, H.; Given, J. W.; Lay, T.

    1982-01-01

    Seismic body waves which were excited by eruption of Mt. St. Helens, and recorded by the Global Digital Seismographic Network (GDSN) stations are analyzed to determine the nature and the time sequence of the events associated with the eruption. The polarity of teleseismic P waves (period 20 sec) is identical at six stations which are distributed over a wide azimuthal range. This observation, together with a very small S to P amplitude ratio (at 20 sec), suggests that the source is a nearly vertical single force that represents the counter force of the eruption. The time history of the vertical force suggests two distinct groups of events, about two minutes apart, each consisting of several subevents with a duration of about 25 sec. The magnitude of the force is approximately 2.6 to the 17th power dyne. this vertical force is in contrast with the long period (approximately 150 sec) southward horizontal single force which was determined by a previous study and interpreted to be due to the massive landslide.

  16. The arrival of the Mount St. Helens eruption cloud over Europe

    NASA Astrophysics Data System (ADS)

    Meixner, F. X.; Georgii, H.-W.; Ockelmann, G.; Jäger, H.; Reiter, R.

    1981-02-01

    The stratospheric aerosol layer between 15 and 25 km altitude is an important factor in the balance of the global radiation budget. The eruption of the Mount St. Helens in Washington, USA, on 18 May 1980 violated the quasi stationary situation in the stratosphere which was established after the decay of the post-Fuego aerosol during the years 1974 to 1976. At tropopause level the cloud was observed over the east coast of the US and Canada on 21 May 1980. The further transport over the Atlantic was estimated by first guess trajectory constructions. The arrival of the eruption cloud over Europe was observed by the authors employing in-situ techniques and remote sensing. The in-situ measurements of atmospheric SO2 were performed during an aircraft ascent up to 13.7 km on 26 May 1980 over southern Scandinavia. In contrast to an aircraft ascent over southern Germany on 24 May 1980 a tenfold increase in SO2 mixing ratio at tropopause level was observed. Remote sensing by ground based ruby lidar at Garmisch-Partenkirchen (47.5°N, 11°E) from 25 May to 29 May 80 indicates an aerosol peak at a height of 11 to 12 km, which was initially coupled to the tropopause, but later clearly separated from that level.

  17. Impact of mount st. Helens eruption on bacteriology of lakes in the blast zone.

    PubMed

    Staley, J T; Lehmicke, L G; Palmer, F E; Peet, R W; Wissmar, R C

    1982-03-01

    Lakes lying within the blast zone of Mount St. Helens showed dramatic increases in heterotrophic bacterial numbers after the eruption of 18 May 1980. The total microscopic counts of bacteria in some of the most severely affected lakes were more than 10 cells per ml, an order of magnitude above the counts in outlying control lakes. Likewise, the numbers of viable bacteria reached levels of more than 10 cells per ml, compated with fewer than 10 cells per ml in control lakes. The CPS medium used for enumeration provided growth of up to 81.5% of the bacteria during sampling of one of the blast zone lakes. The high numbers of bacteria and the efficacy of the viable enumeration procedure are evidence that the lakes have been transformed rapidly from oligotrophy to eutrophy due to the eruption and its aftermath. Organic material leached from the devastated forest vegetation is thought to be responsible for the enrichment of heterotrophs. Total coliform bacteria were found in all of the blast zone lakes, and some lakes contained fecal coliform bacteria. Klebsiella pneumoniae was the predominant total coliform and was also identified as one of the fecal coliform bacteria, although Escherichia coli was the predominant species in that category. Our data indicate that bacterial populations peaked in the outer blast zone lakes in the summer of 1980 and in most of the inner lakes during the summer of 1981. PMID:16345973

  18. Hydrothermal circulation at Mount St. Helens determined by self-potential measurements

    USGS Publications Warehouse

    Bedrosian, P.A.; Unsworth, M.J.; Johnston, M.J.S.

    2007-01-01

    The distribution of hydrothermal circulation within active volcanoes is of importance in identifying regions of hydrothermal alteration which may in turn control explosivity, slope stability and sector collapse. Self-potential measurements, indicative of fluid circulation, were made within the crater of Mount St. Helens in 2000 and 2001. A strong dipolar anomaly in the self-potential field was detected on the north face of the 1980-86 lava dome. This anomaly reaches a value of negative one volt on the lower flanks of the dome and reverses sign toward the dome summit. The anomaly pattern is believed to result from a combination of thermoelectric, electrokinetic, and fluid disruption effects within and surrounding the dome. Heat supplied from a cooling dacite magma very likely drives a shallow hydrothermal convection cell within the dome. The temporal stability of the SP field, low surface recharge rate, and magmatic component to fumarole condensates and thermal waters suggest the hydrothermal system is maintained by water vapor exsolved from the magma and modulated on short time scales by surface recharge. ?? 2006 Elsevier B.V. All rights reserved.

  19. Temporal changes in stress preceding the 2004-2008 eruption of Mount St. Helens, Washington

    USGS Publications Warehouse

    Lehto, H.L.; Roman, D.C.; Moran, S.C.

    2010-01-01

    The 2004-2008 eruption of Mount St. Helens (MSH), Washington, was preceded by a swarm of shallow volcano-tectonic earthquakes (VTs) that began on September 23, 2004. We calculated locations and fault-plane solutions (FPS) for shallow VTs recorded during a background period (January 1999 to July 2004) and during the early vent-clearing phase (September 23 to 29, 2004) of the 2004-2008 eruption. FPS show normal and strike-slip faulting during the background period and on September 23; strike-slip and reverse faulting on September 24; and a mixture of strike-slip, reverse, and normal faulting on September 25-29. The orientation of ??1 beneath MSH, as estimated from stress tensor inversions, was found to be sub-horizontal for all periods and oriented NE-SW during the background period, NW-SE on September 24, and NE-SW on September 25-29. We suggest that the ephemeral ~90?? change in ??1 orientation was due to intrusion and inflation of a NE-SW-oriented dike in the shallow crust prior to the eruption onset. ?? 2010 Elsevier B.V.

  20. Sediment yield following severe volcanic disturbance - A two-decade perspective from Mount St. Helens

    USGS Publications Warehouse

    Major, J.J.; Pierson, T.C.; Dinehart, R.L.; Costa, J.E.

    2000-01-01

    Explosive volcanic eruptions perturb water and sediment fluxes in watersheds; consequently, posteruption sediment yields can exceed pre-eruption yields by several orders of magnitude. Annual suspended-sediment yields following the catastrophic 1980 Mount St. Helens eruption were as much as 500 times greater than typical background level, and they generally declined nonlinearly for more than a decade. Although sediment yields responded primarily to type and degree of disturbance, streamflow fluctuations significantly affected sediment-yield trends. Consecutive years (1995-1999) of above-average discharge reversed the nonlinear decline and rejuvenated yields to average values measured within a few years of the eruption. After 20 yr, the average annual suspended-sediment yield from the 1980 debris-avalanche deposit remains 100 times (104 Mg [megagrams]/km2) above typical background level (~102 Mg/km2). Within five years of the eruption, annual yields from valleys coated by lahar deposits roughly plateaued, and average yields remain about 10 times (103 Mg/km2) above background level. Yield from a basin devastated solely by a blast pyroclastic current diminished to background level within five years. These data demonstrate long-term instability of eruption-generated detritus, and show that effective mitigation measures must remain functional for decades.

  1. Yellow Cat revisited: a review of Helen Cannon's selenium indicator plants

    SciTech Connect

    Arp, G.K.

    1983-03-01

    In the late 1940s, Helen Cannon of the USGS conducted her famous studies on the association of plants to selenium. She used this association for detection of sedimentary uranium deposits on the Colorado plateau. Cannon demonstrated that locoweeds (Astragalus) from the Yellow Cat area of the Thompson district in eastern Utah did reflect the presence of selenium-rich uranium deposits by their colonization of the soils over the deposits. During the subsequent 30 years, Cannon's work has repeatedly been cited as a classic example of the use of indicator geobotany in mineral exploration. During the same 30-year period, geobotanical techniques have not found wide utilization as an exploration tool. Further, Cannon's work has not been demonstrated elsewhere to any extent. In 1980, the author returned to Yellow Cat to see what changes, if any, may have transpired at the site. The author also wanted to gather insight into why geobotanical methods have not gained wider acceptance and perhaps determine why subsequent work is so rare. Results of this study support Cannon's basic work. The results also suggest that the methods are ecologically sound and have applicability to modern mineral exploration programs. Limitations to the method are also discussed, along with some speculation as to why geobotanical methods have not seen wider application.

  2. Secondary hydroeruptions in pyroclastic-flow deposits: Examples from Mount St. Helens

    USGS Publications Warehouse

    Moyer, T.C.; Swanson, D.A.

    1987-01-01

    Secondary hydroeruptions occur in pyroclastic-flow deposits when water or ice is trapped beneath hot pyroclastic debris and rapidly heated to steam. These eruptions display various styles of activity including fumarolic degassing, tephra fountaining, and explosive cratering. The deposits, which occupy the layer 3 stratigraphic position on the top of pyroclastic-flow units, can be distinguished from ash-cloud material by lateral thickness variation, clast composition, and other sedimentary features. The ejecta of secondary hydroeruptions comprise a subset of hydrovolcanic pyroclastic deposits. A small secondary hydroeruption observed on the Mount St. Helens pumice plain in 1981 produced tephra that was emplaced ballistically, by deposition from base surges, and by fallout from an eruption column. Stratigraphic descriptions and grain-size analysis of the ejecta from several secondary craters on the pumice plain demonstrate that the bedforms produced by a hydroeruption change with crater diameter. In particular, craters of small diameter are surrounded by interbedded ripple-laminated ash horizons and nonstratified, fines-depleted units; large craters have ejecta ramparts comprised of coarse dunes and antidunes. These bedform changes are related to a progressive increase in eruptive energy, which produces base surges of greater power and eruptive columns of greater height. We suggest that the style of activity displayed during a secondary hydroeruption is controlled by both the total thermal energy of the system and the permeability of the pyroclastic overburden. ?? 1987.

  3. Mt. St. Helens: Influence of Magmatic Activity on the Biogeochemistry of Thermal Springs

    NASA Astrophysics Data System (ADS)

    Montross, S. N.; Skidmore, M.; Abrahamson, I. S.

    2005-12-01

    Mt St. Helens erupted explosively in 1980, and the intense heat of this event effectively sterilized the crater. The crater is filled with significant ash and volcanic debris and the crater environment has limited vegetation despite relatively abundant water, from rainfall and snowmelt. However, microorganisms thrive in the hot springs that have developed in the crater since the 1980 eruption in this otherwise biologically hostile environment. Channelized drainages exiting the crater contain numerous hot spring sources which result from thermal heating of meteoric water and gain solutes from water-rock interactions. These solutes are important inputs for the microbial communities found within the crater thermal systems. Water samples collected in August 2004 and August 2005 from thermal springs in Step Canyon allow the opportunity to assess the effects of recent magmatic activity in the crater since September 2004, on the aqueous chemistry and microbiology of thermal spring water. We have investigated the composition of microbial communities in crater hot spring ecosystems by identifying small subunit ribosomal RNA sequences amplified directly from extracted genomic DNA. Initial screening of cloned DNA (16S rRNA gene sequence) by restriction fragment length polymorphism and sequencing indicates moderate microbial diversity in this environment with representatives from the domains Bacteria and Archaea. The presentation will examine relationships between the aqueous geochemistry and the microbial communities and temporal changes in these related to the recent magmatic activity.

  4. Monitoring Eruptive Activity at Mount St. Helens with TIR Image Data

    NASA Technical Reports Server (NTRS)

    Vaughan, R. G.; Hook, S. J.; Ramsey, M. S.; Realmuto, V. J.; Schneider, D. J.

    2005-01-01

    Thermal infrared (TIR) data from the MASTER airborne imaging spectrometer were acquired over Mount St. Helens in Sept and Oct, 2004, before and after the onset of recent eruptive activity. Pre-eruption data showed no measurable increase in surface temperatures before the first phreatic eruption on Oct 1. MASTER data acquired during the initial eruptive episode on Oct 14 showed maximum temperatures of similar to approximately 330 C and TIR data acquired concurrently from a Forward Looking Infrared (FLIR) camera showed maximum temperatures similar to approximately 675 C, in narrow (approximately 1-m) fractures of molten rock on a new resurgent dome. MASTER and FLIR thermal flux calculations indicated a radiative cooling rate of approximately 714 J/m(exp 2)/s over the new dome, corresponding to a radiant power of approximately 24 MW. MASTER data indicated the new dome was dacitic in composition, and digital elevation data derived from LIDAR acquired concurrently with MASTER showed that the dome growth correlated with the areas of elevated temperatures. Low SO2 concentrations in the plume combined with sub-optimal viewing conditions prohibited quantitative measurement of plume SO2. The results demonstrate that airborne TIR data can provide information on the temperature of both the surface and plume and the composition of new lava during eruptive episodes. Given sufficient resources, the airborne instrumentation could be deployed rapidly to a newly-awakening volcano and provide a means for remote volcano monitoring.

  5. Monitoring eruptive activity at Mount St. Helens with TIR image data

    USGS Publications Warehouse

    Vaughan, R.G.; Hook, S.J.; Ramsey, M.S.; Realmuto, V.J.; Schneider, D.J.

    2005-01-01

    Thermal infrared (TIR) data from the MASTER airborne imaging spectrometer were acquired over Mount St. Helens in Sept and Oct, 2004, before and after the onset of recent eruptive activity. Pre-eruption data showed no measurable increase in surface temperatures before the first phreatic eruption on Oct 1. MASTER data acquired during the initial eruptive episode on Oct 14 showed maximum temperatures of ???330??C and TIR data acquired concurrently from a Forward Looking Infrared (FLIR) camera showed maximum temperatures ???675??C, in narrow (???1-m) fractures of molten rock on a new resurgent dome. MASTER and FLIR thermal flux calculations indicated a radiative cooling rate of ???714 J/m2/S over the new dome, corresponding to a radiant power of ???24 MW. MASTER data indicated the new dome was dacitic in composition, and digital elevation data derived from LIDAR acquired concurrently with MASTER showed that the dome growth correlated with the areas of elevated temperatures. Low SO2 concentrations in the plume combined with sub-optimal viewing conditions prohibited quantitative measurement of plume SO2. The results demonstrate that airborne TIR data can provide information on the temperature of both the surface and plume and the composition of new lava during eruptive episodes. Given sufficient resources, the airborne instrumentation could be deployed rapidly to a newly-awakening volcano and provide a means for remote volcano monitoring. Copyright 2005 by the American Geophysical Union.

  6. Timing of degassing and plagioclase growth in lavas erupted from Mount St. Helens, 2004-2005, from 210Po-210Pb-226Ra disequilibria: Chapter 37 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

    USGS Publications Warehouse

    Reagan, Mark K.; Cooper, Kari M.; Pallister, John S.; Thornber, Carl R.; Wortel, Matthew; Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

    2008-01-01

    Disequilibrium between 210Po, 210Pb, and 226Ra was measured on rocks and plagioclase mineral separates erupted during the first year of the ongoing eruption of Mount St. Helens. The purpose of this study was to monitor the volatile fluxing and crystal growth that occurred in the weeks, years, and decades leading up to eruption. Whole-rock samples were leached in dilute HCl to remove 210Po precipitated in open spaces. Before leaching, samples had variable initial (210Po) values, whereas after leaching, the groundmasses of nearly all juvenile samples were found to have had (210Po) ≈ 0 when they erupted. Thus, most samples degassed 210Po both before and after the magmas switched from open- to closed-system degassing. All juvenile samples have (210Pb)/(226Ra) ratios within 2 δ of equilibrium, suggesting that the magmas involved in the ongoing eruption did not have strong, persistent fluxes of 222Rn in or out of magmas during the decades and years leading to eruption. These equilibrium values also require a period of at least a century after magma generation and the last significant differentiation of the Mount St. Helens dacites. Despite this, the elevated (210Pb)/(226Ra) value measured in a plagioclase mineral separate from lava erupted in 2004 suggests that a significant proportion of this plagioclase grew within a few decades of eruption. The combined dataset suggests that for most 2004-5 lavas, the last stage of open-system degassing of the dacite magmas at Mount St. Helens is confined to the period between 1-2 years and 1-2 weeks before eruption, whereas plagioclase large enough to be included in the mineral separate grew around the time of the 1980s eruption or earlier.

  7. Constraints and conundrums resulting from ground-deformation measurements made during the 2004-2005 dome-building eruption of Mount St. Helens, Washington: Chapter 14 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

    USGS Publications Warehouse

    Dzurisin, Daniel; Lisowski, Michael; Poland, Michael P.; Sherrod, David R.; LaHusen, Richard G.; Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

    2008-01-01

    Lack of precursory inflation suggests that the volcano was poised to erupt magma already stored in a crustal reservoir when JRO1 was installed in 1997. Trilateration and campaign GPS data indicate surface dilatation, presumably caused by reservoir expansion between 1982 and 1991, but no measurable deformation between 1991 and 2003. We conclude that all three of the traditionally reliable eruption precursors (seismicity, ground deformation, and volcanic gas emission) failed to provide warning that an eruption was imminent until a few days before a visible welt appeared at the surface--a situation reminiscent of the 1980 north-flank bulge at Mount St. Helens.

  8. Seismic-monitoring changes and the remote deployment of seismic stations (seismic spider) at Mount St. Helens, 2004-2005: Chapter 7 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

    USGS Publications Warehouse

    McChesney, Patrick J.; Couchman, Marvin R.; Moran, Seth C.; Lockhart, Andrew B.; Swinford, Kelly J.; LaHusen, Richard G.; Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

    2008-01-01

    The instruments in place at the start of volcanic unrest at Mount St. Helens in 2004 were inadequate to record the large earthquakes and monitor the explosions that occurred as the eruption developed. To remedy this, new instruments were deployed and the short-period seismic network was modified. A new method of establishing near-field seismic monitoring was developed, using remote deployment by helicopter. The remotely deployed seismic sensor was a piezoelectric accelerometer mounted on a surface-coupled platform. Remote deployment enabled placement of stations within 250 m of the active vent.

  9. GeoGirls: A Geology and Geophysics Field Camp for Middle School Girls at Mount St. Helens

    NASA Astrophysics Data System (ADS)

    Samson, C.; Allstadt, K.; Melander, S.; Groskopf, A.; Driedger, C. L.; Westby, E.

    2015-12-01

    The August 2015 GeoGirls program was a project designed to inspire girls to gain an appreciation and enthusiasm for Earth sciences using Mount St. Helens as an outdoor volcanic laboratory. Occupations in the field of science and engineering tend to be held by more males than females. One way to address this is to introduce girls to possible opportunities within the geosciences and encourage them to learn more about the dynamic environment in which they live. In 2015, the GeoGirls program sought to accomplish this goal through organizing a five day-long field camp for twenty middle school-aged girls, along with four high school-aged mentors and two local teachers. This group explored Mount St. Helens guided by female scientists from the USGS Cascade Volcano Observatory (CVO), the Mount St. Helens Institute (MSHI), UNAVCO, Boise State, Georgia Tech, University of Washington and Oregon State University. To introduce participants to techniques used by volcanologists, the girls participated in hands-on experiments and research projects focusing on seismology, GPS, terrestrial lidar, photogrammetry, water and tephra. Participants also learned to collect samples, analyze data and use microscopes. Through this experience, participants acquired strategies for conducting research by developing hypotheses, making observations, thinking critically and sharing their findings with others. The success of the GeoGirls program was evaluated by participant and parent survey questionnaires, which allowed assessment of overall enthusiasm and interest in pursuing careers in the geosciences. The program was free to participants and was run jointly by MSHI and CVO and funded by NSF, the American Association of University Women, the Association for Women Geoscientists, the Association of Environmental & Engineering Geologists and private donors. The program will run again in the summer of 2016.

  10. How useful is the Helen Keller food frequency chart in the determination of the vitamin A status in pregnancy?

    PubMed

    Eigbefoh, J O; Okpere, E E; Ande, B; Asonye, C

    2005-02-01

    Vitamin A deficiency sub clinical or overt, is associated with adverse maternal, fetal and neonatal outcome. This is also true for an excess of vitamin A. The challenge in pregnancy is to detect sub clinical vitamin A deficiency in patients for whom supplements or dietary manipulation will be of benefit. This was a cross sectional case controlled study at the University of Benin Teaching Hospital to compare the Helen Keller Food Frequency Chart with biochemical methods in the determination of vitamin A status in pregnancy. Data was collected from Antenatal patients (142). Using serum Biochemistry three categories of patient were recognized. Patients with normal vitamin A levels (N=100 women with blood vitamin A within two standard deviation of the mean) Twenty-four women (24) had low vitamin A levels (N=24, patients with blood vitamin A level at less than 2 standard deviation below the mean). Eighteen patients (18) had high vitamin A levels (patients with blood vitamin A levels at greater than two standard deviation above the mean). All recruited patients had a dietary assessment using the Helen Keller Food Frequency Chart. The Helen Keller Food Frequency Chart (HKFFC) was found to have a high degree of sensitivity (74.5%) and a high specificity (75%) in detection of patients with vitamin A deficiency. The positive predictive value was 93.62%. The low negative predictive rate of 37.5% however implies that a positive test is more important than a negative test. The HKFFC was unable to differentiate patients with normal or high vitamin A levels. Dietary assessment with the HKFFC is a cheap effective method to detect sub clinical vitamin A deficiency in pregnancy. It is an easy cost effective screening tool to select patients for whom dietary manipulation and or vitamin A supplementation may be beneficial.

  11. Identifying Water on Mt. Baker and Mt. St. Helens, WA with Geophysics: Implications for Volcanic Landslide Hazards

    NASA Astrophysics Data System (ADS)

    Finn, C.; Bedrosian, P.; Wisniewski, M.; Deszcz-Pan, M.

    2015-12-01

    Groundwater position, abundance, and flow rates within a volcano affect the transmission of fluid pressure, transport of mass and heat and formation of mechanically weak hydrothermal alteration influencing the stability of volcanoes. In addition, eruptions can shatter volcanic rocks, weakening the edifice. Helicopter magnetic and electromagnetic (HEM) data collected over Mt. Baker and Mt. St. Helens volcanoes reveal the distribution of water, shattered volcanic rocks and hydrothermal alteration essential to evaluating volcanic landslide hazards. These data, combined with geological mapping and rock property measurements, indicate the presence of localized <100 m thick zones of water-saturated hydrothermally altered rock beneath Sherman Crater and the Dorr Fumarole Fields at Mt. Baker. Nuclear magnetic resonance data indicate that the hydrothermal clays contain ~50% bound water with no evidence for free water ponded beneath the ice. The HEM data suggest water-saturated fresh volcanic rocks from the surface to the detection limit (~100 m) over the entire summit of Mt. Baker (below the ice). A 50-100 m thick high resistivity layer (>1500 ohm-m) corresponding to domes, debris avalanche, volcanic rocks and glaciers mantles the crater at Mt. St. Helens. Shallow low resistivity layers corresponding to fresh, cold water and hot brines are observed below the high resistivity surface in EM data. Shallow ground water mainly concentrates in shattered dome material in the crater of Mt. St. Helens. Aeromagnetic data indicate the location of basalts sandwiched between debris avalanche deposits and shattered dome material. The combination of the EM and magnetic data help map the location of the shattered dome material that is considered to be the failure surface for the 1980 debris avalanche. The EM data image the regional groundwater table near the base of the volcano. The geophysical identification of groundwater and weak layers constrain landslide hazards assessments.

  12. Overview of the 2004-2008 Eruption of Mount St. Helens

    NASA Astrophysics Data System (ADS)

    Gardner, C. A.

    2008-12-01

    Well-monitored and observed volcanic eruptions provide critical data sets needed to understand sub-surface properties, timescales of geophysical and geochemical processes and the conditions necessary to initiate or cease eruptive activity. Mount St. Helens' second eruptive episode within 30 years began on 1 October 2004 with a low-temperature vapor-and-ash emission and ended approximately 40 months later after extrusion of nearly 100 million m3 (DRE) of dacitic lava (roughly equivalent to the volume of the 1980s lava dome) into the 1980s crater. Unlike the episodic explosive and lava-dome-building events that characterized the 1980s eruption, the 2004-2008 episode consisted of continuous lava-dome extrusion punctuated by only two minor explosive events. Seismic unrest heralding the new eruptive episode began in late September 2004 after unseasonally heavy August rains and during a year of overall low seismic activity and no anomalous trends in either deformation or volcanic gas emissions. Soon after the start of increased seismic activity, visible near-field deformation occurred on the south side of the 1980s lava dome, with detectable volcanic gas following several days later. Lava-dome extrusion began in mid-October 2004. Monitoring parameters exhibited gradually diminishing trends such that: (1) significant seismicity accompanied high extrusion rates (>6 to < 2 m3/s) and lava spines with well-developed gouge surfaces during the first year+ of the eruption, but by the last year, when extrusion rates were below 0.5 m3/sec and the gouge surface was smaller and more poorly developed, seismicity had decreased markedly such that the eruption was nearly aseismic; (2) volcanic gas emission rates, which were barely above background by the end of the first year, were barely above instrumental limits during the last year of the eruption; and (3) flank and far-field deflation centered on the crater starting in late September 2004, dropped monotonically to below noise level

  13. Magma reservoirs from the upper crust to the Moho inferred from high-resolution Vp and Vs models beneath Mount St. Helens

    NASA Astrophysics Data System (ADS)

    Kiser, E.; Palomeras, I.; Levander, A.; Zelt, C. A.; Harder, S. H.; Schmandt, B.; Hansen, S. M.; Creager, K. C.; Ulberg, C. W.

    2015-12-01

    Seismic investigations following the 1980 eruption of Mount St. Helens have led to a detailed model of the magmatic and tectonic structure directly beneath the volcano. These studies suffer from limited resolution below ~10 km, making it difficult to estimate the volume of the shallow magma reservoir beneath the volcano, the regions of magma entry into the lower crust, and the connectivity of this magma system throughout the crust. The latter is particularly interesting as one interpretation of the Southern Washington Cascades Conductor (SWCC) suggests that the Mount St Helens and Mount Adams volcanic systems are connected in the crust (Hill et al., 2009). The multi-disciplinary iMUSH (imaging Magma Under St. Helens) project is designed to investigate these and other fundamental questions associated with Mount St. Helens. Here we present the first high-resolution 2D Vp and Vs models derived from travel-time data from the iMUSH 3D active-source seismic experiment. Significant lateral heterogeneity exists in both the Vp and Vs models. Directly beneath Mount St. Helens we observe a high Vp/Vs body, inferred to be the upper/middle crustal magma reservoir, between 4 and 13 km depth. Southeast of this body is a low Vp column extending from the Moho to approximately 15 km depth. A cluster of low frequency events, typically associated with injection of magma, occurs at the northwestern boundary of this low Vp column. Much of the recorded seismicity between the shallow high Vp/Vs body and deep low Vp column took place in the months preceding and hours following the May 18, 1980 eruption. This may indicate a transient migration of magma between these two reservoirs associated with this eruption. Outside of the inferred magma bodies that feed Mount St. Helens, we observe several other interesting velocity anomalies. In the lower crust, high Vp features bound the low Vp column. One explanation for these features is the presence of lower crustal cumulates associated with

  14. Cessation of the 2004-2008 Dome-Building Eruption at Mount St. Helens, Washington

    NASA Astrophysics Data System (ADS)

    Moran, S. C.; Dzurisin, D.; Lisowski, M.; Schilling, S. P.; Anderson, K. R.; Werner, C. A.

    2015-12-01

    The 2004-2008 dome-building eruption at Mount St. Helens ended during the winter of 2007-2008 at a time when field observations were hampered by persistent bad weather. As a result, recognizing the end of the eruption was challenging. Also challenging was the fact that signs of continued eruption were increasingly subtle — earthquakes were small, deformation signals tiny, gas content close to background — and observing these phenomena was critically dependent on recordings and measurements made close (< 2 km) to the vent. In hindsight, the end of the eruption was presaged by a slight increase in seismicity in December 2007 that culminated on January 12-13, 2008, with a flurry of more than 500 events, most of which occurred in association with several tremor-like signals and a spasmodic burst of long-period earthquakes. At about the same time, a series of regular, localized, small-amplitude tilt events — thousands of which had been recorded during earlier phases of the eruption — came to an end. Thereafter, seismicity declined to 10-20 events per day until January 27-28, when a spasmodic burst of about 50 volcano-tectonic earthquakes occurred over a span of 3 hours. This was followed by a brief return of repetitive "drumbeat" earthquakes that characterized much of the eruption. By January 31, seismicity had declined to 1-2 earthquakes per day, a rate similar to pre-eruption levels. We attribute the tilt and seismic observations to progressive stagnation of an increasingly stiffened plug of magma in the upper part of the conduit. Upward movement of the plug ceased when the excess driving pressure, which had gradually decreased throughout the eruption as a result of reservoir deflation and increasing overburden from the growing dome, was overcome by increasing sidewall friction as a result of cooling and crystallization of the plug.

  15. Hydrometeor-enhanced tephra sedimentation: Constraints from the 18 May 1980 eruption of Mount St. Helens

    USGS Publications Warehouse

    Durant, A.J.; Rose, William I.; Sarna-Wojcicki, A. M.; Carey, Steven; Volentik, A.C.M.

    2009-01-01

    Uncertainty remains on the origin of distal mass deposition maxima observed in many recent tephra fall deposits. In this study the link between ash aggregation and the formation of distal mass deposition maxima is investigated through reanalysis of tephra fallout from the Mount St. Helens 18 May 1980 (MSH80) eruption. In addition, we collate all the data needed to model distal ash sedimentation from the MSH80 eruption cloud. Four particle size subpopulations were present in distal fallout with modes at 2.2 ??, 4.2 ??, 5.9 ??, and 8.3 ??. Settling rates of the coarsest subpopulation closely matched predicted single-particle terminal fall velocities. Sedimentation of particles <100 ??m was greatly enhanced, predominantly through aggregation of a particle subpopulation with modal diameter 5.9 ?? 0.2 ?? (19 ?? 3 ??m). Mammatus on the MSH80 cloud provided a mechanism to transport very fine ash particles, with predicted atmospheric lifetimes of days to weeks, from the upper troposphere to the surface in a matter of hours. In this mechanism, ash particles initiate ice hydrometeor formation high in the troposphere. Subsequently, the volcanic cloud rapidly subsides as mammatus develop from increased particle loading and cloud base sublimation. Rapid fallout occurs as the cloud passes through the melting level in a process analogous to snowflake aggregation. Aggregates sediment en masse and form the distal mass deposition maxima observed in many recent volcanic ash fall deposits. This work provides a data resource that will facilitate tephra sedimentation modeling and allow model intercomparisons. Copyright 2009 by the American Geophysical Union.

  16. A Volcano Rekindled: The Renewed Eruption of Mount St. Helens, 2004-2006

    USGS Publications Warehouse

    Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

    2008-01-01

    Mount St. Helens began a dome-building eruption in September 2004 after nearly two decades of quiescence. Dome growth was initially robust, became more sluggish with time, and ceased completely in late January 2008. The volcano has been quiet again since January 2008. Professional Paper 1750 describes the first 1 1/2 years of this eruptive activity, chiefly from September 2004 until December 2005. Its 37 chapters contain contributions of 87 authors from 23 institutions, including the U.S. Geological Survey, Forest Service, many universities, and local and State emergency management agencies. Chapter topics range widely - from seismology, geology, geodesy, gas geochemistry, and petrology to the human endeavor required for managing the public volcanic lands and distributing information during the hectic early days of a renewed eruption. In PDF format, the book may be downloaded in its entirety or by its topical sections, each section including a few prefatory paragraphs that describe the general findings, recurrent themes, and, in some cases, the unanswered questions that arise repeatedly. Those readers who prefer downloading the smaller files of only a chapter or two have this option available as well. Readers are directed to chapter 1 for a general overview of the eruption and the manner in which different chapters build our knowledge of events. More detailed summaries for specific topics can be found in chapter 2 (seismology), chapter 9 (geology), chapter 14 (deformation), chapter 26 (gas geochemistry), and chapter 30 (petrology). The printed version of the book may be purchased as a hardback weighty tome (856 printed pages) that includes a DVD replete with the complete online version, including all chapters and several additional appendixes not in the printed book.

  17. Mount St. Helens: Controlled-source audio-frequency magnetotelluric (CSAMT) data and inversions

    USGS Publications Warehouse

    Wynn, Jeff; Pierce, Herbert A.

    2015-01-01

    The apparent conductivity (or its inverse, apparent resistivity) measured by a geoelectrical system is caused by several factors. The most important of these are water-filled rock porosity and the presence of water-filled fractures; however, rock type and minerals (for instance, sulfides and clay content) also contribute to apparent conductivity. In situations with little recharge (for instance, in arid regions), variations in ionic content of water occupying pore space and fractures sampled by the measurement system must also be factored in (Wynn, 2006). Variations in ionic content may also be present in hydrothermal fluids surrounding volcanoes in wet regions. In unusual cases, temperature may also affect apparent conductivity (Keller, 1989; Palacky, 1989). There is relatively little hydrothermal alteration (and thus fewer clay minerals that might add to the apparent conductivity) in the eruptive products of Mount St. Helens (Reid and others, 2010), so conductors observed in the Fischer, Occam, and Marquardt inversion results later in this report are thus believed to map zones with significant water content. Geoelectrical surveys thus have the potential to reveal subsurface regions with significant groundwater content, including perched and regional aquifers. Reid and others (2001) and Reid (2004) have suggested that groundwater involvement may figure in both the scale and the character of some if not all volcanic edifice collapse events. Ongoing research by the U.S. Geological Survey (USGS) and others aims to better understand the contribution of groundwater to both edifice pore pressure and rock alteration as well as its direct influence on eruption processes by violent interaction with magma (Schmincke, 1998).

  18. The 2004–2008 dome-building eruption at Mount St. Helens, Washington: Epilogue

    USGS Publications Warehouse

    Dzurisin, Daniel; Moran, Seth C.; Lisowski, Michael; Schilling, Steve P.; Anderson, Kyle R.; Werner, Cynthia A.

    2015-01-01

    The 2004–2008 dome-building eruption at Mount St. Helens ended during winter 2007–2008 at a time when field observations were hampered by persistent bad weather. As a result, recognizing the end of the eruption was challenging—but important for scientists trying to understand how and why long-lived eruptions end and for public officials and land managers responsible for hazards mitigation and access restrictions. In hindsight, the end of the eruption was presaged by a slight increase in seismicity in December 2007 that culminated on January 12–13, 2008, with a burst of more than 500 events, most of which occurred in association with several tremor-like signals and a spasmodic burst of long-period earthquakes. At about the same time, a series of regular, localized, small-amplitude tilt events—thousands of which had been recorded during earlier phases of the eruption—came to an end. Thereafter, seismicity declined to 10–20 events per day until January 27–28, when a spasmodic burst of about 50 volcano-tectonic earthquakes occurred over a span of 3 h. This was followed by a brief return of repetitive “drumbeat” earthquakes that characterized much of the eruption. By January 31, however, seismicity had declined to 1–2 earthquakes per day, a rate similar to pre-eruption levels. We attribute the tilt and seismic observations to convulsive stagnation of a semisolid magma plug in the upper part of the conduit. The upward movement of the plug ceased when the excess driving pressure, which had gradually decreased throughout the eruption as a result of reservoir deflation and increasing overburden from the growing dome, was overcome by increasing friction as a result of cooling and crystallization of the plug.

  19. The uranium and thorium decay series nuclides in Mt. St. Helens effusives

    NASA Astrophysics Data System (ADS)

    Bennett, J. T.; Krishnaswami, S.; Turekian, K. K.; Melson, W. G.; Hopson, C. A.

    1982-08-01

    The concentrations of the radionuclides 238U, 230Th, 226Ra, 210Pb, 210Po, 232Th, 228Ra and 228Th and the abundances of major elements were determined in samples from all major eruptions of Mt. St. Helens from May 18, 1980 through June 21, 1981. During this time the effusives changed from plagioclase-phyric dacite to a more andesitic composition but the concentrations of U and Th series nuclides were measurably invariant. The average 232Th/ 238U weight ratio in the rocks is 2.4 and the 230Th/ 232Th activity ratio equals the 238U/ 232Th activity ratio indicating no fractionation of U from Th during magma genesis. 226Ra activity is in excess (˜40% on average) of its parent 230Th whereas 228Ra is in radioactive equilibrium with its parent 232Th, constraining the time of magma formation between 30 and 10 4 years prior to eruption. The 210Pb/ 226Ra activity ratios in the samples average 1.0, with a 20% scatter on either side, but allowing for volatile 210Pb loss at time of eruption excess 210Pb over 226Ra is inferred, indicating that the time of magma formation was within the last 150 years. 210Po was virtually absent in the samples immediately after eruption, indicating its total loss by volatilization during eruption. The quantity of 210Po volatilized during the May 18, 1980 event is estimated to be in the range of 300 Ci from the effusives and as much as 5000 Ci total including losses from heated slide material. The 222Rn activity volatilized should have been comparable to the 210Po activity released.

  20. Effects of lava-dome growth on the crater glacier of Mount St. Helens, Washington: Chapter 13 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

    USGS Publications Warehouse

    Walder, Joseph S.; Schilling, Steve P.; Vallance, James W.; LaHusen, Richard G.; Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

    2008-01-01

    The process of lava-dome emplacement through a glacier was observed for the first time as the 2004-6 eruption of Mount St. Helens proceeded. The glacier that had grown in the crater since the cataclysmic 1980 eruption was split in two by the new lava dome. The two parts of the glacier were successively squeezed against the crater wall. Photography, photogrammetry, and geodetic measurements document glacier deformation of an extreme variety, with strain rates of extraordinary magnitude as compared to normal temperate alpine glaciers. Unlike such glaciers, the Mount St. Helens crater glacier shows no evidence of either speed-up at the beginning of the ablation season or diurnal speed fluctuations during the ablation season. Thus there is evidently no slip of the glacier over its bed. The most reasonable explanation for this anomaly is that meltwater penetrating the glacier is captured by a thick layer of coarse rubble at the bed and then enters the volcano’s groundwater system rather than flowing through a drainage network along the bed. Mechanical consideration of the glacier-squeeze process also leads to an estimate for the driving pressure applied by the growing lava dome.

  1. Radar interferometry observations of surface displacements during pre- and coeruptive periods at Mount St. Helens, Washington, 1992-2005: Chapter 18 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

    USGS Publications Warehouse

    Poland, Michael; Lu, Zhong; Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

    2008-01-01

    We analyzed hundreds of interferograms of Mount St. Helens produced from radar images acquired by the ERS-1/2, ENVISAT, and RADARSAT satellites during the 1992-2004 preeruptive and 2004-2005 coeruptive periods for signs of deformation associated with magmatic activity at depth. Individual interferograms were often contaminated by atmospheric delay anomalies; therefore, we employed stacking to amplify any deformation patterns that might exist while minimizing random noise. Preeruptive interferograms show no signs of volcanowide deformation between 1992 and the onset of eruptive activity in 2004. Several patches of subsidence in the 1980 debris-avalanche deposit were identified, however, and are thought to be caused by viscoelastic relaxation of loosely consolidated substrate, consolidation of water-saturated sediment, or melting of buried ice. Coeruptive interferometric stacks are dominated by atmospheric noise, probably because individual interferograms span only short time intervals in 2004 and 2005. Nevertheless, we are confident that at least one of the seven coeruptive stacks we constructed is reliable at about the 1-cm level. This stack suggests deflation of Mount St. Helens driven by contraction of a source beneath the volcano.

  2. The mechanics of ground deformation precursory to dome-building extrusions at Mount St. Helens 1981-1982.

    USGS Publications Warehouse

    Chadwick, W.W.; Archuleta, R.J.; Swanson, D.A.

    1988-01-01

    Detailed monitoring at Mount St. Helens since 1980 has enabled prediction of the intermittent eruptive activity (mostly dome growth) with unprecedented success. During 1981 and 1982, accelerating deformation of the crater floor around the vent (including radial cracks, thrust faults, and ground tilt) was the earliest indicator of impending activity. The magnitude of the shear stress required to match observed dipslacements (1-7 MPa) is inversely proportional to the conduit diameter (estimated to be 25-100 m). The most probable source of this shear stress is the flow of viscous magma up to the conduit and into the lava dome. A model is proposed in which the accelerating deformation, beginning as much as 4 weeks before extrusions, is caused by the increasing velocity of ascending magma in the conduit. This model is examined by using deformation data of the dome before four extrusions in 1981 and 1982 to estimate the volumetric flow rate through the conduit. This flow rate and an estimate of the effective viscosity of the magma enable calculation of an ascent velocity and an applied shear stress that, again, depend on the conduit diameter. The results of these calculations are consistent with the finite element experiments and show that the proposed model is feasible. Precursory deformation like that measured at Mount St. Helens should be observable at similar volcanoes elsewhere because it is caused by the fundamental process of magma ascent.-from Authors

  3. Little Black Sambo: A Closer Look. A History of Helen Bannerman's The Story of Little Black Sambo and its Popularity/Controversy in the United States.

    ERIC Educational Resources Information Center

    Yuill, Phyllis J.

    Surprisingly little research has been done on Little Black Sambo and the meager material is often contradictory. This study examines the origins of the book and traces its history in the United States through its overlapping periods of popularity and controversy. The story of Little Black Sambo, written in 1898 by Helen Bannerman, a white English…

  4. An Overview of the Project on the Imaging and Full-Text Retrieval of the Ava Helen and Linus Pauling Papers at the Oregon State University Libraries.

    ERIC Educational Resources Information Center

    Krishnamurthy, Ramesh S.; Mead, Clifford S.

    1995-01-01

    Presents plan of Oregon State University Libraries to convert all paper documents from the Ava Helen and Linus Pauling archives to digital format. The scope, goals, tasks and objectives set by the project coordinators are outlined, and issues such as protection of equipment, access, copyright and management are discussed. (JKP)

  5. Commentary on: "On the Need for a Specialist Service within the Generic Hospital Setting" by Robyn A. Wallace and Helen Beange (2008)

    ERIC Educational Resources Information Center

    Kerr, Michael

    2008-01-01

    This commentary discusses whether a sufficient case has been made for specialism in hospital services as a viable alternative to existing generic services. The impact of developments in specialist care such as those outlined by Robyn A. Wallace and Helen Beange should be assessed as a means of reducing inequality. In particular, model services…

  6. Evaluation of gas data from high-temperature fumaroles at Mount St. Helens, 1980-1982

    USGS Publications Warehouse

    Gerlach, T.M.; Casadevall, T.J.

    1986-01-01

    The Mount St. Helens fumarole gases show linear composition trends during periods of noneruptive degassing between September 1980 and October 1981. The trends are characterized by increasing H2O and decreasing CO2 and sulfur. Maximum fumarole temperatures also show a linear decrease during this period. High-temperature fumarole gases collected from the crater and dome between September 1980 and July 1982 are all H2O-rich (> 90%) with 1-10% CO2 and small amounts of H2S, SO2, H2, CO, HC, and HF. Trace amounts of COS and S2 are present, and occasional observations of minor CH4 appear to result from contamination or low-temperature reactions in sample vessels. The O2 fugacities of the gases remain near Ni-NiO during cooling. The low sulfur content of the gases obviates the need for extensive gas-rock oxygen exchange to maintain fO2's near Ni-NiO. A detailed thermodynamic analysis of 50 gas samples collected between September 1980 and December 1981 led to improved compositions for 22 samples. The gases were initially in a state of equilibrium, but disequilibrium modifications from atmospheric oxidation of H2 and, to a lesser extent, CO occurred within the upper portions of the fumarole vents. The last temperatures of equilibrium for the fumarole gases range from 800??C to 650??C and are nearly always higher than the collection temperatures. No evidence was found of disequilibrium admixture of surface waters; if such modifications of the fumarole gases occurred, the water must have been added at depth and have reequilibrated with the other gas species at magmatic or near-magmatic temperatures. The highest quality analytical data are obtained by field gas chromatograph measurements and from caustic soda bottle samples. Samples collected in evacuated bottles or by pumping through double stopcock tubes tend to be severely deficient in sulfur due to post-collection reactions between H2S and SO2. It is also necessary to infer the water content of the latter samples. ?? 1986.

  7. The source of infrasound associated with long-period events at mount St. Helens

    USGS Publications Warehouse

    Matoza, R.S.; Garces, M.A.; Chouet, B.A.; D'Auria, L.; Hedlin, M.A.H.; De Groot-Hedlin, C.; Waite, G.P.

    2009-01-01

    During the early stages of the 2004-2008 Mount St. Helens eruption, the source process that produced a sustained sequence of repetitive long-period (LP) seismic events also produced impulsive broadband infrasonic signals in the atmosphere. To assess whether the signals could be generated simply by seismic-acoustic coupling from the shallow LP events, we perform finite difference simulation of the seismo-acoustic wavefield using a single numerical scheme for the elastic ground and atmosphere. The effects of topography, velocity structure, wind, and source configuration are considered. The simulations show that a shallow source buried in a homogeneous elastic solid produces a complex wave train in the atmosphere consisting of P/SV and Rayleigh wave energy converted locally along the propagation path, and acoustic energy originating from , the source epicenter. Although the horizontal acoustic velocity of the latter is consistent with our data, the modeled amplitude ratios of pressure to vertical seismic velocity are too low in comparison with observations, and the characteristic differences in seismic and acoustic waveforms and spectra cannot be reproduced from a common point source. The observations therefore require a more complex source process in which the infrasonic signals are a record of only the broadband pressure excitation mechanism of the seismic LP events. The observations and numerical results can be explained by a model involving the repeated rapid pressure loss from a hydrothermal crack by venting into a shallow layer of loosely consolidated, highly permeable material. Heating by magmatic activity causes pressure to rise, periodically reaching the pressure threshold for rupture of the "valve" sealing the crack. Sudden opening of the valve generates the broadband infrasonic signal and simultaneously triggers the collapse of the crack, initiating resonance of the remaining fluid. Subtle waveform and amplitude variability of the infrasonic signals as

  8. Communicating Potential Ash-Fall Hazards With Scenario Maps at Mount St. Helens

    NASA Astrophysics Data System (ADS)

    Ewert, J. W.; Griswold, J.; Wardwell, R. S.; Bohlander, A.

    2006-12-01

    Shortly after the reawakening of Mount St. Helens in September 2004, the USGS Cascades Volcano Observatory (CVO) began producing twice-daily ash-fall-scenario maps to aid in eruption response on the part of scientists and emergency managers. We use the advection-diffusion-sedimentation program ASHFALL of Hurst (1994) and numerical forecast winds from the NOAA Air Resources Laboratory to produce the maps for 00 and 12 hours UTC. The ASHFALL program produces a gridded output of potential uncompacted tephra thicknesses. We produce scenario maps using bulk tephra volumes of 1 and 10 million cubic meters (MCM), with column heights of 7 and 12 km, respectively. These volumes are judged to cover the range of possible tephra volumes that the ongoing dome-building eruption is capable of producing. Thus far, none of the few tephra-producing eruptive events since 2004 has ejected more than several hundred thousand MCM of tephra. Georeferenced gridded output from the ASHFALL program is imported to GIS software so that it can be visualized on a regional map. These maps are distributed to personnel at CVO to aid in communicating hazards information in daily updates of the volcanoe's activity, and to emergency management officials and the public in the event of a tephra producing event. In late 2004, at the start of the current eruption period, the ashfall scenario maps were used to support contingency planning in the Joint Operations Center in Vancouver, Washington and in the Washington State Emergency Operations Center. At the present time, gridded output is sent directly to the State of Washington's Emergency Management Division where they are incorporated into their GIS-based emergency information system, ready to be distributed to local emergency management entities in case of an ash-producing event. Having daily scenario maps in hand facilitates rapid communication of where ashfall is likely to occur. Once an event is underway, the ASHFALL program is run using observed

  9. Characterization of plasma mirrors on the HELEN laser infrared CPA beam

    NASA Astrophysics Data System (ADS)

    Andrew, James E.; Comley, Andrew J.

    2008-10-01

    The performance of plasma mirrors has been characterised on the HELEN laser infra-red, chirped pulse amplification [CPA] beam line. This laser produced pulse energies up to 100J with pulse lengths of ~500fs. Plasma mirrors are initially low reflectance surfaces that transmit low intensity light but produce a reflecting plasma surface when exposed to high irradiance beams. Typically they are formed by transparent substrates at the laser wavelength and have been used either uncoated or with anti-reflection coatings. The coatings evaluated in these experiments were either multi-layer dielectrics or single layer sol-gel silica. Some of the fused silica substrates were coated on both faces, others were coated on the incident face only and a small number were used uncoated. The reflectance of the plasma mirrors was measured as a function of incident energy. A vacuum compatible pyro-electric sensor in conjunction with either a diffuser or neutral density filter was used to measure incident and reflected laser energy. Both the diffuser and filter could suffer laser damage at the highest incident energies available. The morphology of the damage of the different components and coating combinations was studied as a function of incident beam energy. The mirrors were being investigated to prevent pre-pulse effects in plasma physics experiments and increase the intensity contrast ratio of the laser beam incident onto solid targets. Their proximity to the laser target also allowed them to block debris and shrapnel arising from the laser matter interaction in some directions. These material emissions spread uncontrollably in the evacuated target chamber and may cause contamination of laser optics and filters or radiation diagnostic instrumentation. The plasma mirror components were operated at 45 degrees angle of incidence and an average input beam diameter of 5.5 millimetres at the mirrors with incident beam irradiances in the range 50 TW/cm2 to 540 TW/cm2. The reflected beams

  10. A Laboratory Study of the 2004-2008 Mount St Helens Lava Dome: Mechanical Behaviour, Rheology, and Earthquakes.

    NASA Astrophysics Data System (ADS)

    Smith, R.; Sammonds, P. R.; Tuffen, H.; Meredith, P. G.

    2009-05-01

    Lava domes are often modelled as a fluid whose dynamics are controlled by the viscosity and pressurisation of the fluid. However, the behaviour of active domes such as the 2004-2008 Mount St Helens dome and spine complex reveals that most of the lava dome deformation occurs on shear fracture planes. Evidence from seismology and exposed magma conduits at other volcanoes also indicates that the final ascent of magma into these domes may be controlled by shear fracture zones at the conduit margins. These observations demonstrate that fracturing may exert a stronger control on lava dome dynamics than fluid mechanics does. It is therefore important to expand the limited existing data on the high temperature rock mechanics of dome lavas under eruptive conditions. Acoustic emissions (AE) recorded whilst producing such data can provide a link between laboratory experiments and seismicity recorded during lava dome eruptions. Here we present results of uniaxial and triaxial deformation of a dacite sample extruded at Mount St Helens lava dome in December 2005, which has unsurpassed age constraints. This provides the unique opportunity to compare experimental results to the geophysical signals recorded as the sample was extruded. A newly modified high temperature triaxial compression apparatus was used to deform 25 mm diameter cylindrical samples at temperatures up to 1000°C, effective pressures up to 10 MPa, and strain rates from 10-4 s-1 to 10-6 s-1. It was thus possible to deform samples at temperatures, strain rates, and effective pressures typical of the Mount St Helens lava dome system and of active andesitic and dacitic lava dome systems in general, whilst also recording AE. The experimental results show the effect of temperature, effective pressure, and strain rate on the compressive strength, failure mode, and rheology of dome lavas within the brittle ductile transition. They provide key parameters and constraints for developing numerical and analytical models of

  11. Multiple-pulsed debris avalanche emplacement at Mount St. Helens in 1980: Evidence from numerical continuum flow simulations

    NASA Astrophysics Data System (ADS)

    Sousa, James; Voight, Barry

    1995-07-01

    The complex 1980 Mount St. Helens debris avalanche is modeled numerically as a transient biviscous fluid flow. Several approaches are considered, including two-step rheologically-distinct models for avalanche I and combined avalanches II/III, and a composite flow model consisting of retrogressive slides of identical rheology successively accreted to the main avalanche flow. For the two-step situation, flow rheologies are evaluated separately for the initial avalanche, comprising the debris avalanche block facies, and an ensuing explosive-influenced flow. Strengths (normalized by density) as high as 250 m 2/s 2 and apparent Newtonian viscosities as much as 275 m 2/s were established for the block facies. These parameters for the explosively-influenced flow are an order of magnitude lower. The distribution of stratigraphic units within flowing model debris, compared with field distributions, suggests that the higher-strength emplacement models are appropriate for debris deposited on Johnston Ridge and in the upper parts and flanks of the North Fork Toutle River valley. In general, models for which constant rheology is assumed throughout the flow process provide lower-bound emplacement times, and excessive early velocities, as compared to the prototype event. Because model calibration is based on matching runout by trial and error, it is therefore biased toward the rheologic parameters essential to achieving that runout. These values characterize the flow in its latter stages, whereas the actual strength and viscosity may have substantially decreased as a function of displacement. Two-dimensional models predict debris accumulation about twice as thick as that observed at the foot of Mount St. Helens, where flow divergence was significant. This discrepancy is lessened with a quasi-three-dimensional modification of the flow model. Accretionary composite flow models with homogeneous rheology simulate the overriding of early avalanche debris by later debris pulses. The

  12. Separating long-term deformation cycles and atmospheric signals at Mount St. Helens using PS-InSAR

    NASA Astrophysics Data System (ADS)

    Welch, M.

    2015-12-01

    Since its eruption in 1980, Mount St. Helens has experienced multiple inflation-deflation cycles associated with dome building eruptions. During the most recent dome-building episode, which spanned 2004 to 2008, GPS recorded the transition from pre-eruptive inflation to co-eruptive deflation and a final transition back to inflation. Such observations provide important constraints on the timing and mechanics of cyclic magma recharge and extrusion. Currently, the subtle surface deformation signal at St Helens is monitored primarily by ground based geodetic techniques like GPS. Satellite-based InSAR has the potential to substantially augment these techniques by providing spatially continuous, precise measurements of surface displacements, and may also reveal other volcanic or surficial processes too localized to be detected by ground based methods. Traditional interferometry is challenging to apply to volcanoes in the Cascades. Widespread phase decorrelation caused by persistent snow cover and dense vegetation, combined with large, elevation dependent atmospheric phase delays, mask or make deformation signals difficult to detect. By applying StaMPS, a Persistent Scatterers (PS) technique, phase decorrelation is mitigated by utilizing only the pixels with the highest, statistically derived, signal to noise ratio. However, atmospheric water vapor, which delays the radar signal, remains problematic, particularly on the volcano edifice. To assess the bias imposed by the atmosphere, we perform a series of sensitivity tests using a suite of methods including several that rely on the linear or power-law correlation of phase delay to topography and knowledge of the spatial scale of the signal. We also apply methods that calculate wet and dry phase delay from atmospheric reanalysis datasets such as ERA-Interim provided by the ECMWF. SAR data from the ERS, Envisat, and ALOS satellites, along with newer datasets, are processed with these tools to create a time series spanning

  13. Fumarole emissions at Mount St. Helens volcano, June 1980 to October 1981: Degassing of a magma-hydrothermal system

    USGS Publications Warehouse

    Gerlach, T.M.; Casadevall, T.J.

    1986-01-01

    This study is an investigation of the chemical changes in the Mount St. Helens fumarole gases up to October 1981, the sources of the fumarole gases, and the stability of gas species in the shallow magma system. These problems are investigated by calculations of element compositions, thermodynamic equilibria, and magmatic volatile-hydrothermal steam mixing models. The fumarole gases are treated as mixtures of magmatic volatiles and hydrothermal steam formed by magma degassing and boiling of local waters in a dryout zone near conduit and dome magma. The magmatic volatile fraction is significant in fumaroles with temperatures in excess of the magma cracking-temperature (??? 700??C) - i.e., the temperature below which cracking is induced by thermal stresses during cooling and solidification. Linear composition changes of the fumarole gases over time appear to be the result of a steady decline in the magmatic volatile mixing fraction, which may be due to the tapping of progressively volatile-depleted magma. The maximum proportion of hydrothermal steam in the fumaroles rose from about 25-35% in September 1980 to around 50-70% by October 1981. Fractional degassing of magmatic CO2 and sulfur also contributed to the chemical changes in the fumarole gases. The steady chemical changes indicate that replenishment of the magma system with undegassed magma was not significant between September 1980 and September 1981. Extrapolations of chemical trends suggest that fumarole gases emitted at the time of formation of the first dome in mid-June 1980 were more enriched in a magmatic volatile fraction and contained a minimum of 9% CO2. Calculations show H2S is the predominant sulfur species in Mount St. Helens magma below depths of 200 m. Rapid release of gases from magma below this depth is a plausible mechanism for producing the high H2S/SO2 observed in Mount St. Helens plumes during explosive eruptions. This study suggests that dacite-andesite volcanos may emit gases richer in CO2

  14. Petrology of the 2004-2006 Mount St. Helens lava dome -- implications for magmatic plumbing and eruption triggering: Chapter 30 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

    USGS Publications Warehouse

    Pallister, John S.; Thornber, Carl R.; Cashman, Katharine V.; Clynne, Michael A.; Lowers, Heather; Mandeville, Charles W.; Brownfield, Isabelle K.; Meeker, Gregory P.; Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

    2008-01-01

    The question of new versus residual magma has implications for the long-term eruptive behavior of Mount St. Helens, because arrival of a new batch of dacitic magma from the deep crust could herald the beginning of a new long-term cycle of eruptive activity. It is also important to our understanding of what triggered the eruption and its future course. Two hypotheses for triggering are considered: (1) top-down fracturing related to the shallow groundwater system and (2) an increase in reservoir pressure brought about by recent magmatic replenishment. With respect to the future course of the eruption, similarities between textures and character of eruption of the 2004-6 dome and the long-duration (greater than 100 years) pre-1980 summit dome, along with the low eruptive rate of the current eruption, suggest that the eruption could continue sluggishly or intermittently for years to come.

  15. Remote camera observations of lava dome growth at Mount St. Helens, Washington, October 2004 to February 2006: Chapter 11 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

    USGS Publications Warehouse

    Poland, Michael P.; Dzurisin, Daniel; LaHusen, Richard G.; Major, John J.; Lapcewich, Dennis; Endo, Elliot T.; Gooding, Daniel J.; Schilling, Steve P.; Janda, Christine G.; Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

    2008-01-01

    Images from a Web-based camera (Webcam) located 8 km north of Mount St. Helens and a network of remote, telemetered digital cameras were used to observe eruptive activity at the volcano between October 2004 and February 2006. The cameras offered the advantages of low cost, low power, flexibility in deployment, and high spatial and temporal resolution. Images obtained from the cameras provided important insights into several aspects of dome extrusion, including rockfalls, lava extrusion rates, and explosive activity. Images from the remote, telemetered digital cameras were assembled into time-lapse animations of dome extrusion that supported monitoring, research, and outreach efforts. The wide-ranging utility of remote camera imagery should motivate additional work, especially to develop the three-dimensional quantitative capabilities of terrestrial camera networks.

  16. Extrusion rate of the Mount St. Helens lava dome estimated from terrestrial imagery, November 2004-December 2005: Chapter 12 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

    USGS Publications Warehouse

    Major, Jon J.; Kingsbury, Cole G.; Poland, Michael P.; LaHusen, Richard G.; Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

    2008-01-01

    Oblique, terrestrial imagery from a single, fixed-position camera was used to estimate linear extrusion rates during sustained exogenous growth of the Mount St. Helens lava dome from November 2004 through December 2005. During that 14-month period, extrusion rates declined logarithmically from about 8-10 m/d to about 2 m/d. The overall ebbing of effusive output was punctuated, however, by episodes of fluctuating extrusion rates that varied on scales of days to weeks. The overall decline of effusive output and finer scale rate fluctuations correlated approximately with trends in seismicity and deformation. Those correlations portray an extrusion that underwent episodic, broad-scale stick-slip behavior superposed on the finer scale, smaller magnitude stick-slip behavior that has been hypothesized by other researchers to correlate with repetitive, nearly periodic shallow earthquakes.

  17. From dome to dust: shallow crystallization and fragmentation of conduit magma during the 2004-2006 dome extrusion of Mount St. Helens, Washington: Chapter 19 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

    USGS Publications Warehouse

    Cashman, Katharine V.; Thornber, Carl R.; Pallister, John S.; Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

    2008-01-01

    Comparison of eruptive conditions during the 2004-6 activity at Mount St. Helens with those of other spine-forming eruptions suggests that magma ascent rates of about 10-4 m/s or less allow sufficient degassing and crystallization within the conduit to form large volcanic spines of intermediate composition (andesite to dacite). Solidification deep within the conduit, in turn, requires transport of the solid plug over long distances (hundreds of meters); resultant large strains are responsible for extensive brittle breakage and development of thick gouge zones. Moreover, similarities between gouge textures and those of ash emitted by explosions from spine margins indicate that fault gouge is the origin for the ash. As the comminution and generation of ash-sized particles was clearly a multistep process, this observation suggests that fragmentation preceded, rather than accompanied, these explosions.

  18. Mass Intrusion at Mount St. Helens (WA) Between 2010 and 2014 from Temporal Gravity Variations Mass Intrusion at Mount St. Helens (WA) Between 2010 and 2014 from Temporal Gravity Variations

    NASA Astrophysics Data System (ADS)

    Battaglia, M.; Lisowski, M.; Dzurisin, D.; Poland, M. P.

    2014-12-01

    Repeated high-precision gravity measurements made at Mount St. Helens (WA) have revealed systematic temporal variations in the gravity field several years after the 2004-2008 dome-building eruption. Changes in gravity with respect to a stable reference station 36 km NW of the volcano were measured at 10 sites in the summit region and at 4 sites far afield (10 to 36 km) from the summit in August 2010 and August 2012. After removing the gravity signal associated with changes in mass of the crater glacier and the local (perched) hydrothermal aquifer, the gravity field observed at sites near the volcano's summit significantly increased with respect to sites far from the summit (maximum change 146 ±7 μgal). The pattern of gravity increase is radially symmetrical, with a half-width around 3 km and a point of maximum change centered 1.5 km NW of the 2004-2008 lava dome. Inversion of residual gravity data using the same source geometry, depth and location inferred from geodetic data (a spheroidal source centered 7.5 km beneath the 2004-2008 dome) indicates a mass increase of about 1012 kg. For a reasonable magma density (~2250 kg/m3), the volume of magma intrusion beneath the summit region inferred from gravity exceeds the volume inferred from inversion of geodetic data, suggesting that magma compressibility and other processes are important aspects of magma storage at Mount St. Helens. A third survey will be completed in August 2014, and we will present results of those measurements in the context of the 2010-2012 gravity changes.

  19. Rates and processes of channel development and recovery following the 1980 eruption of Mount St. Helens, Washington

    USGS Publications Warehouse

    Meyer, D.F.; Martinson, H.A.

    1989-01-01

    Stream channel development in response to the eruption of Mount St. Helens on 18 May 1980, resulted in some of the largest sediment yields documented anywhere on earth. Development of new channels on the 2.7 km3 debris-avalanche deposit in the North Fork Toutle River caused net erosion of as much as 1.3 X 105 t km-2 annually. The principal effect of the blast on channels throughout the 550 km2 devastated area was the subsequent rapid delivery of sand- and silt-size sediment eroded from hillslopes. Since 1984, instability and sedimentation in lahar and blast-affected channels have been within the range of pre-1980 levels. -from Authors

  20. Fluoride distribution and biological availability in the fallout from Mount St. Helens, 18 to 21 May 1980

    SciTech Connect

    Taves, D.R.

    1980-12-19

    Concentrations of fluoride in the ash fallout in central Washington from the 18 May 1980 eruption of Mount St. Helens varied severalfold, but none are high enough to constitute any immediate hazard to animal life. The heaviest fallout (Moses Lake) contained 113 parts per million (ppm) of acid-labile fluoride, but of this only 11 ppm was water-soluble and 20 ppm was available to rats. The fluoride concentrations in the urine of cattle feeding for 4 days on hay contaminated with this ash were essentially normal. Samples of ash from other areas generally had higher concentrations of acid-labile fluoride but lower concentrations of water-soluble fluoride. The concentrations of water-soluble fluoride was inversely correlated with the coarseness of the fallout. 8 references, 1 figure, 1 table.

  1. Fluoride distribution and biological availability in the fallout from mount st. Helens, 18 to 21 may 1980.

    PubMed

    Taves, D R

    1980-12-19

    Concentrations of fluoride in the ash fallout in central Washington from the 18 May 1980 eruption of Mount St. Helens varied severalfold, but none are high enough to constitute any immediate hazard to animal life. The heaviest fallout (Moses Lake) contained 113 parts per million (ppm) of acid-labile fluoride, but of this only 11 ppm was water-soluble and 20 ppm was available to rats. The fluoride concentrations in the urine of cattle feeding for 4 days on hay contaminated with this ash were essentially normal. Samples of ash from other areas generally had higher concentrations of acid-labile fluoride but lower concentrations of water-soluble fluoride. The concentration of water-soluble fluoride was inversely correlated with the coarseness of the fallout. PMID:17817849

  2. Human radiation studies: Remembering the early years. Oral history of Oncologist Helen Vodopick, M.D., December 28, 1994

    SciTech Connect

    1995-08-01

    This report is a transcript of an interview with Dr. Helen Vodopick by representatives of the US DOE Office of Human Radiation Experiments. Dr. Vodopick was chosen for this interview because of her involvement with the Oak Ridge Institute of Nuclear Studies (ORINS) and Oak Ridge Associated Universities (ORAU) experimental cancer-therapy program involving total-body irradiation. After a short biographical sketch Dr. Vodopick relates her remembrances of the Medium-Exposure-Rate Total Body Irradiator (METBI), ORINS radioisotope tracer studies, treatment of cancer patients with the METBI, radiation treatment for leukemia patients, bone marrow treatment of leukemia, the Low-Exposure-Rate Total Body Irradiation (LETBI), treatment of radiation accident victims at ORAU, research with radioactive phosphorus and sulfur, and public opinion issues.

  3. Explosive tephra emissions of Mount St. Helens, 1989-1991: the violent escape of magmatic gas following storms?

    USGS Publications Warehouse

    Mastin, L.G.

    1994-01-01

    From 24 August 1989 until 18 June 1991, Mount St. Helens produced at least 28 shallow, explosion-like seismic events with signatures similar to those produced by gas explosions on the dome during the mid 1980s. At least six were accompanied by violent emission of non-juvenile tephra, ejection of blocks of rock nearly 1 km from the vent, and avalanching of debris off the north side of the dome. All six confirmed emissions and most (although not all) other seismic events took place hours to days after storms. The short delay between storms and emissions suggests that the events that follow storms originate at very shallow depth, probably within the dome itself. Although the exact causal mechanism is not known, it is speculated that slope instability or accelerated growth of cooling fractures following storms may have released gas trapped within or at the base of the dome. -from Author

  4. Chemistry of thermal waters and mineralogy of the new deposits at Mount St. Helens: a preliminary report

    SciTech Connect

    Dethier, D.P.; Frank, D.; Peavear, D.R.

    1980-12-01

    After May 18, 1980 eruption of Mount St. Helens, Washington, interactions between the hot deposits and shallow ground water produced ephemeral phreatic eruptions and thermal ponds and streams. In early June water and sediment samples were collected from about 20 sites in the devastated zone to study the initial alteration of the new deposits, and the effects of the eruption on water chemistry. The levels of certain trace elements in thermal waters, and whether these mineralized waters were reaching the North Fork Toutle River in appreciable quantities were studied. Collection and analysis procedures, the mineralogy of the new deposits, and the chemistry of the thermal waters are discussed. Finally, the chemistry of water from different deposits is compared, alteration reactions suggested by the water chemistry, and the mineralogy of the deposits is discussed.

  5. Characterization of dissolved organic materials in surface waters within the blast zone of Mount St Helens, Washington

    USGS Publications Warehouse

    McKnight, Diane M.; Pereira, W.E.; Ceazan, M.L.; Wissmar, Robert C.

    1982-01-01

    After the May 18, 1980, eruption of Mount St Helens, the concentration of dissolved organic material in surface waters near the volcano increased significantly as a result of the destruction of the surrounding conifer forest. Low molecular weight organic compounds identified in the blast zone surface waters were derived from pyrolysis of plant and soil organic materials incorporated into pyroclastic flow, mud flow and debris avalanche deposits. A major fraction of the dissolved organic material consisted of high molecular weight, colored, organic acids that are similar in their general properties to aquatic fulvic acids found in more typical surface waters except for greater sulfur contents. The other major fraction of the dissolved organic material consisted of hydrophilic acids, which may include compounds capable of supporting heterotrophic microorganisms, and precursors in the formation of aquatic fulvic acids. The organic chemistry of blast zone surface waters will probably be greatly influenced by the May 18, 1980, eruption for many years. ?? 1982.

  6. Turbulent dynamics and pyroclastic flow generation during the Mount St. Helens May 18th, 1980 eruption

    NASA Astrophysics Data System (ADS)

    Andrews, B. J.; Gardner, J. E.

    2007-12-01

    Eruption behavior at Mount St. Helens changed greatly over the course of 18 May: a buoyant, Plinian column dominated the morning phases of eruption, whereas during the early afternoon, the column partially collapsed, such that a Plinian column and non-buoyant pyroclastic flows were simultaneously erupted. Changes in the plume's turbulent flow dynamics, pyroclastic fall and flow deposit grain size distributions (GSDs), and character of the plume reflect this evolution in eruption dynamics. Optical flow velocimetry of video of the plume immediately above the crater rim indicates the sizes of the largest structures in the plume decreased from a range of ~300 to >1000 m during the morning to 150-200 m during the afternoon. These measurements agree with visual inspection of photographs showing eddy size decreasing from a range of 200 to >500 m (average 300 m) in the morning to a range of 150-350 m (average 250) in the afternoon. During this same time interval, the rotation speed of eddies (as measured by the rms values of the 2D velocity field) increased by a factor of 1.6. Furthermore, the appearance of the column changed through the course of the eruption. In the morning, the column was characterized by discontinuous, large eddies frequently depositing "curtains" of pyroclasts, and an indentation was present on the column's southern margin. In contrast, the column margins were completely covered by smaller eddies and no curtains of sedimenting pyroclasts during the afternoon. Given that during the morning most mass erupted as buoyant plumes, we have estimated total eruptive GSDs from fall deposit GSDs using known mass fluxes and plume sedimentation models. Accounting for changes in buoyant mass flux and depositional axis, the afternoon Plinian fall deposits are 0.5 to 1 phi units coarser than models predict if the bulk, buoyant GSD remained the same. Although the majority of pyroclastic flows were emplaced to the north of the crater during the afternoon, smaller

  7. Mount St. Helens Volcano Reawakens: An Overview of the First Month of Activity

    NASA Astrophysics Data System (ADS)

    Gardner, C. A.; Sisson, T.; Scott, W. E.

    2004-12-01

    Late in the evening of 22 September 2004, a shallow (< 2 km), high-frequency earthquake swarm began beneath Mount St. Helens volcano in southwest Washington. Seismicity declined and then, on the afternoon of 25 September and the following day, rapidly increased both in rate and magnitude. This prompted the U.S. Geological Survey's Cascades Volcano Observatory to issue an alert above background level for the first time since the 1980s. Over the following week, maximum earthquake magnitudes increased to M3.5 and the first steam-and-ash emission occurred on 1 October. Four additional steam-and-ash emissions occurred through 5 October; the last and largest sent an ash plume to 15,000 feet. Seismicity then dropped to low levels and changed character to more low-frequency events where it remains as of 24 October. Throughout, earthquake locations have remained shallow. By 30 September, field observers noted localized deformation on the south side of the 1980-86 lava dome and adjacent glacier, but in retrospect the deformation probably began earlier. The volume of the deforming area, or welt, grew to 5.4 million cubic meters by 4 October, grew to 11.7 million cubic meters by 13 October, and continues growing. Gas-sensing flights began on 27 September and detected only a few point sources of magmatic gas over the next several days. By 4 October, however, emission rates for carbon dioxide were large enough to be detected in the plume and by 7 October emissions rates for carbon dioxide, hydrogen sulfide and sulfur dioxide were readily measured. Since 7 October, sulfur dioxide has remained the principal sulfur gas. Forward-Looking InfraRed (FLIR) images from 1 to 10 October recorded increasing, but well below magmatic, temperatures on the northwest flank of the welt. On 11 October, temperature measurements of 500 to 600 degrees C coincided with the appearance of a lava spine on the northwest side of the welt that heralded the beginning of exogenous dome growth. Microbeam

  8. Measuring the Dome Growth of the 2004-2005 Eruption of Mount St. Helens

    NASA Astrophysics Data System (ADS)

    Schilling, S. P.; Denlinger, R.; Thompson, R. A.; Messerich, J.

    2005-12-01

    In October 2004, a new period of dome growth began that changed the topography of the 1980 crater at Mount St. Helens dramatically. From October 2004 through July 2005, nearly 60 million cubic meters of lava extruded onto the crater floor immediately south of the 1980-1986 lava dome. The eruption intensely deformed and divided the crater glacier on this floor. It created spectacular crevassing and rapid advance of the east arm of the glacier then caused crevassing and broad uplift of the glacier's west arm. Time-sequential vertical aerial photography documents morphologic change and enabled construction of a series of 13 2-m-resolution digital elevation models (DEMs) for the period between October 4, 2004 and July 14, 2005. Vertical aerial photographs flown at a nominal 1:12000 scale were acquired at three-week intervals, scanned at 12-micron resolution, and rectified using a soft-copy (i.e., digital image) photogrammetric workstation. Aerotriangulated models were constructed using ground control outside the area of active deformation, derived from pre-eruption GPS and photogrammetric data, and passed to subsequent model sets. Resulting location accuracy is on the order of decimeters. The DEM data allow us to estimate dome volumes during growth. To extract volumetric changes and calculate extrusion rates, each DEM surface was compared to pre-eruption reference surfaces from 2000 and 2003, as well as to the preceding DEM surface. On July 14, 2005, the new dome was approximately 700 m long (NW-SE) and 560 m wide (SW-NE). The volume of the new dome (including talus), was about 58 million cubic meters, approximately two-thirds the volume of the 1980-1986 dome. The volumetric growth rate in 2004-2005 ranged from a maximum of 9 m3/sec in the early stages of growth to an average of 1-3 m3/sec thereafter. The DEMs also are used to quantify dome height variations, size of the conduit opening, and the mechanics of dome emplacement (growth and collapse) as well as deformation

  9. Spatial and temporal patterns of dome extrusion during the 2004-2008 eruption of Mount St. Helens

    NASA Astrophysics Data System (ADS)

    Salzer, J. T.; Denlinger, R. P.; Diefenbach, A. K.; Walter, T. R.

    2014-12-01

    Extensive efforts by the USGS Cascades Volcano Observatory in response to the 2004-2008 dome building eruption at Mount St. Helens recorded the extrusion of seven dacite spines. Efforts included a network of time-lapse cameras. Published studies of decimated data from these cameras show strong correlations between (long-term) extrusion velocities determined from the camera imagery and ancillary geophysical data, such as dome tilt and RSAM seismicity. However, more detailed analysis of these data should provide better constraints on physical processes behind dome extrusion. Here we apply modern computer vision techniques to explore the spatiotemporal variability and interactions occurring during spine extrusion and dome growth. Digital Image Correlation (DIC) delineates the deformation field in a series of images at sub-pixel level, and quantifies dome, talus and glacier deformation at unprecedented resolution, revealing spatiotemporal variability of the strain field on the time scale of hours. We identify sharp boundaries between the vertically extruding spine, laterally displaced material, and downward-creeping talus. The spine growth at Mount St. Helens appears locally constrained and structurally separated into distinct segments. The velocities of different dome segments are generally correlated, but displacement patterns of the talus are more complex. We identify short term fluctuations with periods of hours to days superimposed on longer term fluctuations having periods of several weeks. The short term episodes of high displacement rates are often associated with strongly degassing plumes observed in the camera imagery. Over longer periods (days to weeks), extrusion rates form a sinusoidal fluctuating pattern, marked by sharp increases and gradual decreases in velocity. These observations substantiate the correlations with seismic and geodetic data shown in previous studies, but more closely constrain the velocity fluctuations of each spine. These fluctuations

  10. Tomographic Imaging of the Magmatic System at Mount St. Helens with the iMUSH Broadband Array

    NASA Astrophysics Data System (ADS)

    Ulberg, C. W.; Creager, K. C.; Levander, A.; Kiser, E.; Moran, S. C.; Abers, G. A.; Schmandt, B.; Vidale, J. E.; Houston, H.; Denlinger, R. P.; Williams, M. C. B.

    2015-12-01

    We deployed 70 broadband seismometers in the summer of 2014 to image the velocity structure beneath Mount St. Helens (MSH), Washington, USA as part of a collaborative project called imaging Magma Under St. Helens (iMUSH). Our goal is to illuminate the MSH magmatic system, using active- and passive-source seismology, magnetotellurics and petrology. Details of the velocity structure, coupled with other geophysical and geologic data, can help constrain the geometry and physical state of any bodies of melt beneath the volcano. The broadband array has a diameter of ~100 km centered on MSH with an average station spacing of 10 km, and will remain deployed through summer 2016. It is augmented by dozens of permanent stations in the area. We determine P-wave arrival times using Antelope software and incorporate permanent network picks for the region. We use the program struct3DP to invert travel times to obtain a 3-D seismic velocity model and relocate hypocenters, computing travel times using a 3-D eikonal-equation solver. There were more than 500 useable local events during the first year of iMUSH broadband recording, which to date have provided 5000 arrival times, with the number growing rapidly. The local events include 23 active shots that were set off in the summer of 2014 as part of the iMUSH experiment, which recorded with good signal-to-noise ratios across the entire array. The absolute P times will be augmented by differential times calculated by cross-correlation between observations at the same station for nearby event pairs. These will be incorporated into our model using double-difference tomography. We anticipate that our 3D velocity model will provide the highest resolution image of volcanic plumbing at MSH thus far. Our model interpretation will incorporate results from active-source and ambient noise tomography, receiver functions, magnetotellurics, and petrology.

  11. Doing more with short period data: Determining magnitudes from clipped and over-run seismic data at Mount St. Helens

    NASA Astrophysics Data System (ADS)

    Wellik, John J., II

    How can we calculate earthquake magnitudes when the signal is clipped and over-run? When a volcano is very active, the seismic record may saturate (i.e., the full amplitude of the signal is not recorded) or be over-run (i.e., the end of one event is covered by the start of a new event). The duration, and sometimes the amplitude, of an earthquake signal are necessary for determining event magnitudes; thus, it may be impossible to calculate earthquake magnitudes when a volcano is very active. This problem is most likely to occur at volcanoes with limited networks of short period seismometers. This study outlines two methods for calculating earthquake magnitudes when events are clipped and over-run. The first method entails modeling the shape of earthquake codas as a power law function and extrapolating duration from the decay of the function. The second method draws relations between clipped duration (i.e., the length of time a signal is clipped) and the full duration. These methods allow for magnitudes to be determined within 0.2 to 0.4 units of magnitude. This error is within the range of analyst hand-picks and is within the acceptable limits of uncertainty when quickly quantifying volcanic energy release during volcanic crises. Most importantly, these estimates can be made when data are clipped or over-run. These methods were developed with data from the initial stages of the 2004-2008 eruption at Mount St. Helens. Mount St. Helens is a well-studied volcano with many instruments placed at varying distances from the vent. This fact makes the 2004-2008 eruption a good place to calibrate and refine methodologies that can be applied to volcanoes with limited networks.

  12. A quiet revolution in Brighton: Dr Helen Boyle's pioneering approach to mental health care, 1899-1939.

    PubMed

    Westwood, L

    2001-12-01

    At the close of the nineteenth century, the English lunacy laws in relation to pauper cases made no concessions for acute, temporary, or recoverable cases. They were all located in the asylum along with severe and chronic cases. Dr Helen Boyle worked among London's poor in the 1890s and observed the deterioration of cases of nervous disorder and borderline insanity due to their lack of treatment. The early treatment of borderline cases was the aim of Boyle's charitable hospital, founded in 1905, for nervous disorders in women and girls. Boyle's interest in mental disorder included the mentally defective and she was a founder member of the Guardianship Society which sought to keep those defined as such within the community. The history of the care and treatment of the 'insane' has concentrated largely on the public and private asylums. London-based facilities such as the Tavis-tock clinic and the Maudsley Hospital, which both treated rate-aided patients in the inter-war period, have been given a great deal of attention because of wealthy benefactors and the involvement of high profile individuals. Boyle's unique in-patient facility in Brighton preceded the Maudsley by almost 20 years and as such fills an important gap in mental health history. Boyle's work challenged the lunacy laws and set out to establish a holistic system of care for recoverable conditions outside the asylum system. This essay concentrates on the work of Dr Helen Boyle in Brighton but also highlights other facilities that were available for rate-aided patients, which have been neglected in the historiography of mental health care.

  13. Peak flow responses to landscape disturbances caused by the cataclysmic 1980 eruption of Mount St. Helens, Washington

    USGS Publications Warehouse

    Major, J.J.; Mark, L.E.

    2006-01-01

    Years of discharge measurements that precede and follow the cataclysmic 1980 eruption of Mount St. Helens, Washington, provide an exceptional opportunity to examine the responses of peak flows to abrupt, widespread, devastating landscape disturbance. Multiple basins surrounding Mount St. Helens (300-1300 km2 drainage areas) were variously disturbed by: (1) a debris avalanche that buried 60 km2 of valley; (2) a lateral volcanic blast and associated pyroclastic flow that destroyed 550 km2 of mature forest and blanketed the landscape with silt-capped lithic tephra; (3) debris flows that reamed riparian corridors and deposited tens to hundreds of centimeters of gravelly sand on valley floors; and (4) a Plinian tephra fall that blanketed areas proximal to the volcano with up to tens of centimeters of pumiceous silt, sand, and gravel. The spatially complex disturbances produced a variety of potentially compensating effects that interacted with and influenced hydrological responses. Changes to water transfer on hillslopes and to flow storage and routing along channels both enhanced and retarded runoff. Rapid post-eruption modifications of hillslope surface textures, adjustments of channel networks, and vegetation recovery, in conjunction with the complex nature of the eruptive impacts and strong seasonal variability in regional climate hindered a consistent or persistent shift in peak discharges. Overall, we detected a short-lived (5-10 yr) increase in the magnitudes of autumn and winter peak flows. In general, peak flows were larger, and moderate to large flows (>Q2yr) were more substantively affected than predicted by early modeling efforts. Proportional increases in the magnitudes of both small and large flows in basins subject to severe channel disturbances, but not in basins subject solely to hillslope disturbances, suggest that eruption-induced modifications to flow efficiency along alluvial channels that have very mobile beds differentially affected flows of

  14. Seismic scattering and absorption mapping of debris flows, feeding paths, and tectonic units at Mount St. Helens volcano

    NASA Astrophysics Data System (ADS)

    De Siena, L.; Calvet, M.; Watson, K. J.; Jonkers, A. R. T.; Thomas, C.

    2016-05-01

    Frequency-dependent peak-delay times and coda quality factors have been used jointly to separate seismic absorption from scattering quantitatively in Earth media at regional and continental scale; to this end, we measure and map these two quantities at Mount St. Helens volcano. The results show that we can locate and characterize volcanic and geological structures using their unique contribution to seismic attenuation. At 3 Hz a single high-scattering and high-absorption anomaly outlines the debris flows that followed the 1980 explosive eruption, as deduced by comparison with remote sensing imagery. The flows overlay a NNW-SSE interface, separating rocks of significant varying properties down to 2-4 km, and coinciding with the St. Helens Seismic Zone. High-scattering and high-absorption anomalies corresponding to known locations of magma emplacement follow this signature under the volcano, showing the important interconnections between its feeding systems and the regional tectonic boundaries. With frequency increasing from 6 to 18 Hz the NNW-SSE tectonic/feeding trends rotate around an axis centered on the volcano in the direction of the regional-scale magmatic arc (SW-NE). While the aseismic high-scattering region WSW of the volcano shows no evidence of high absorption, the regions of highest-scattering and absorption are consistently located at all frequencies under either the eastern or the south-eastern flank of the volcanic edifice. From the comparison with the available geological and geophysical information we infer that these anomalies mark both the location and the trend of the main feeding systems at depths greater than 4 km.

  15. Effects of the 1980 eruption of Mount St. Helens on the limnological characteristics of selected lakes in western Washington. Water resources investigations

    SciTech Connect

    Embrey, S.S.; Dion, N.P.

    1988-01-01

    The 1980 eruption of Mount St. Helens, Washington, afforded an opportunity to study its physical, chemical, and biological effects on lakes near the volcano and to describe two newly created lakes. From June 1980 to August 1982, water samples were collected from four lakes in the blast zone and two outside the blast zone, as well as from the two newly created lakes. Concentrations of chemical constituents were inversely related to the distance of a lake from the volcano. The recovery of physical, chemical, and biological characteristics of the lakes will depend on stabilization of the volcano and lake watersheds, dilution and water-exchange rates, and biological processes within each lake. Excluding Spirit Lake from consideration, it was estimated from the study that St. Helens Lake would be the slowest of the study lakes to recover, and Venus Lake would be the fastest.

  16. Thermal surveillance of active volcanoes using the LANDSAT-1 data collection system. Part 3: Heat discharge from Mount St. Helens, Washington

    NASA Technical Reports Server (NTRS)

    Friedman, J. D.; Frank, D. (Principal Investigator)

    1977-01-01

    The author has identified the following significant results. Two thermal anomalies, A at 2740 m altitude on the north slope, and B between 2650 and 2750 m altitude on the southwest slope at the contact of the dacite summit dome of Mount St. Helens, Washington were confirmed by aerial infrared scanner surveys between 1971 and 1973. LANDSAT 1 data collection platform 6166, emplaced at site B anomaly, transmitted 482 sets of temperature values in 1973 and 1974, suitable for estimating the differential radiatin emission as 84 W/sq m, approximately equivalent to the Fourier conductive flux of 89 W/sq m in the upper 15 cm below the surface. The differential geothermal flux, including heat loss via evaporation and convection, was estimated at 376 W/sq m. Total energy yield of Mount St. Helens probably ranges between 0.1 and 0.4 x 10 to the 6th power W.

  17. Observations of the eruptions of July 22 and August 7, 1980, at Mount St. Helens, Washington

    USGS Publications Warehouse

    Hoblitt, Richard P.

    1986-01-01

    The explosive eruptions of July 22 and August 7, 1980, at Mount St. Helens, Wash., both included multiple eruptive pulses. The beginnings of three of the pulses-two on July 22 and one on August 7-were witnessed and photographed. Each of these three began with a fountain of gases and pyroclasts that collapsed around the vent and generated a pyroclastic density flow. Significant vertical-eruption columns developed only after the density flows were generated. This behavior is attributable to either an increase in the gas content of the eruption jet or a decrease in vent radius with time. An increase in the gas content may have occurred as the vent was cleared (by expulsion of a plug of pyroclasts) or as the eruption began to tap deeper, gas-rich magma after first expelling the upper, gas-depleted part of the magma body. An effective decrease of the vent radius with time may have occurred as the eruption originated from progressively deeper levels in the vent. All of these processes-vent clearing; tapping of deeper, gas-rich magma; and effective decrease in vent radius-probably operated to some extent. A 'relief-valve' mechanism is proposed here to account for the occurrence of multiple eruptive pulses. This mechanism requires that the conduit above the magma body be filled with a bed of pyroclasts, and that the vesiculation rate in the magma body be inadequate to sustain continuous eruption. During a repose interval, vesiculation of the magma body would cause gas to flow upward through the bed of pyroclasts. If the rate at which the magma produced gas exceeded the rate at which gas escaped to the atmosphere, the vertical pressure difference across the bed of pyroclastic debris would increase, as would the gas-flow rate. Eventually a gas-flow rate would be achieved that would suddenly diminish the ability of the bed to maintain a pressure difference between the magma body and the atmosphere. The bed of pyroclasts would then be expelled (that is, the relief valve would

  18. Using amphibole phenocrysts to track vapor transfer during magma crystallization and transport: An example from Mount St. Helens, Washington

    USGS Publications Warehouse

    Rowe, M.C.; Kent, A.J.R.; Thornber, C.R.

    2008-01-01

    In order to evaluate and further constrain models for volatile movement and vapor enrichment of magma stored at shallow levels, amphibole phenocrysts from 2004-2005 Mount St. Helens dacite were analyzed for major and selected trace elements (Li, Cu, Zn, Mn, and REE) and Li isotopes. Several recent studies have examined fluid-mobile trace element abundances in phencryst phases and melt inclusions as a means of tracking volatile movement within subvolcanic magmatic systems, and high Li contents in plagioclase phenocrysts from 1980 and 2004 Mount St. Helens dacites have been interpreted as evidence that shallow magma was fluxed by a Li-bearing vapor phase prior to eruption. In amphibole phenocrysts, Zn and Mn behave compatibly, correlating to FeO* and Al2O3, and show no systematic change with time. In contrast, Li and Cu abundances in amphibole vary by up to 3 orders of magnitude (7.6-1140????g/g and 1.7 to 94????g/g, respectively), and do not generally correlate with either major or trace elements. However, they do correlate moderately well (R2 = 0.54, >> 95% confidence) with each other and show systematic temporal variations that are opposite to those observed for plagioclase, precluding a simple 1-step diffusion model for Li enrichment. We propose a Diffusion-Crystallization Multi-Stage (DCMS) model to explain the temporal variations and co-variations of Li and Cu. In early erupted dacite (October-December 2004) profiles of Li isotopes in conjunction with measured 7Li intensities and core-to-rim increases in Li concentration are characteristic of Li diffusion into the amphiboles, consistent with prior models of plagioclase enrichment. In amphiboles from 2005 dacite, average Li and Cu concentrations are high (??? 260-660????g/g and ??? 29-45????g/g, respectively) and in contrast to amphiboles from earlier-erupted dacite, correlate weakly with Al2O3??wt.%. Amphibole Al2O3 concentrations are an indicator of pressure, with high-Al amphiboles crystallizing at higher

  19. Mechanisms of Strain Localization within the 2004-2008 Mt. St. Helens lava domes: The role of effusion rate?

    NASA Astrophysics Data System (ADS)

    Friedlander, B.; Kennedy, L.; Russell, J. K.; Pallister, J. S.

    2010-12-01

    Degassed, high viscosity magmas commonly erupt from volcanic vents to produce mounds, domes and spines of partly to fully crystallized lava. Although lava domes are generally products effusive styles of eruption, these systems have the capacity to rapidly switch from effusive to explosive behavior. Soufriere Hills, Montserrat and Unzen, Japan volcanoes have each demonstrated the ability to oscillate between effusive growth of lava domes and the gravitational collapse of these unstable landforms, leading to explosive pyroclastic eruptions. Mount St. Helens reawakened 24 years after erupting in the 1980’s to produce a series of 7 dacitic lava domes and spines from 2004-2008. The rate of extrusion of lava domes peaked at 6 m3/second in November 2004 and subsequently slowed to < 0.6 m3/s in February 2006. These early spines were mantled by 1-3 meters of fault gouge and were accompanied by a consistent “drum beat” microseismicity that was monitored closely by the USGS Cascades Volcano Observatory. Here we present field, petrographic and microstructural observations on the nature of deformation attending the extrusion of the 2004-2006 dacite lava domes at Mount St. Helens. Specifically, we have produced a series of metre-scale maps showing the transition in structural state from the massive, undeformed dacite to the cataclasite and gouge zones of Spine 4, 5 and 6. These maps elucidate the strain partitioning and zones of deformation within the spines. Samples collected from across these zones are currently being studied to recover the microstructural deformation mechanisms attending the extrusion of these dacite spines. The shear zones vary in thickness and range in thickness from one to three meters from Spines 4- 6. The outermost damage zones range in thickness from 1-100cm of fault gouge composed of fractured dacite and wall rocks interleaved with layers of fine to coarse-grained slickensides. Below the gouge, spines 4 and 5 show mostly brittle deformation with

  20. Sediment transport at gaging stations near Mount St. Helens, Washington, 1980-90, data collection and analysis

    USGS Publications Warehouse

    Dinehart, Randal L.

    1998-01-01

    River sedimentation caused by the May 18, 1980, eruption of Mount St. Helens, Washington, has been monitored in a continuing program by the U.S. Geological Survey. In this report, sediment discharge and changes in sediment transport are summarized from data collected at stream-gaging stations near Mount St. Helens during the years 1980 through 1990. The objectives of the monitoring program included collection of data for calculation of total sediment discharge, computation of daily suspended-sediment discharge, and detailed observations of unique sediment-laden flows. Over the 11-year period, most sediment data were collected at gaging stations on seven eruption affected streams: the Green River, the North and South Fork Toutle Rivers, the Toutle River, the Cowlitz River, Clearwater Creek, and the Muddy River. About 170 million tons of sediment (excluding volcanic debris flows) were transported in suspension from the Toutle River basin during water years 1980–90. Another 13 million tons were transported past the gaging stations on Muddy River in the upper Lewis River basin during water years 1982–90. Long-term reductions in sediment concentration occurred within most ranges of stream discharge at streams dominated by transport from the debris-avalanche deposit and at streams in drainage basins with extensive airfall deposits. Reductions in sediment concentration were less apparent at upper ranges of discharge in two streams dominated by lahar deposits, the South Fork Toutle River and the Muddy River. Bed material, suspended sediment, and bedload were sampled periodically and analyzed for size distributions. Bed material and bedload coarsened with time at some stations. Median particle sizes of suspended sediment did not show a simple relation with time. During water years 1980–84, bed material in the lower Toutle River was medium to coarse sand. During the same period, bed material in the North Fork Toutle River was coarse sand and fine gravel. By 1990

  1. Volcano dome dynamics at Mount St. Helens: Deformation and intermittent subsidence monitored by seismicity and camera imagery pixel offsets

    NASA Astrophysics Data System (ADS)

    Salzer, J. T.; Thelen, W. A.; James, M. R.; Walter, T. R.; Moran, S. C.; Denlinger, R. P.

    2015-12-01

    The morphology of a volcanic lava dome and its rate of change play key roles in the estimation of dome stability. While long term variations of dome morphology can be quantified using aerial remote sensing, changes over shorter time scales and smaller spatial scales are more difficult to determine. However, intermittent destabilization of the dome, in particular on flanks of the domes, can be significant. This study focuses on short term deformation associated with earthquakes and tremor at Mount St. Helens, observed over a 6 week period in the summer of 2006. We use Digital Image Correlation (DIC) to compute the displacement field between successive optical images acquired by multiple fixed cameras with clear views of the dome. The results of the these calculations are compared to the occurrence of seismic events. A systematic time-series DIC analysis of image pairs showed no sharp changes in the dome morphology during periods without seismic events. However, the results reveal that the steady dome growth at Mount St. Helens was interrupted by short term displacements reaching magnitudes on the order of a meter. These displacements are only observed in association with low frequency, large magnitude seismic events, followed by tremor with frequencies between 5 Hz and likely exceeding 30 Hz. For selected events that coincide with the timing of the acquisition of an accurate DEM of the crater floor, we reproject the displacement fields obtained from two cameras onto the topography. This enables 3D displacement vectors to be derived, showing that the co-seismic deformation is marked by subsidence of the dome in a segmented fashion, the central region displaying mainly vertical motion, while the displacements on the talus are more slope-parallel. The exact relationship between the recorded seismic energy and the observed deformation of the dome can not be resolved because the cameras were only sampling every 15 - 60 minutes. However, our analysis suggests that the

  2. Grain-size characteristics of experimental pyroclasts of 1980 Mount St. Helens cryptodome dacite: effects of pressure drop and temperature

    NASA Astrophysics Data System (ADS)

    Spieler, Oliver; Alidibirov, Mikhail; Dingwell, Donald

    2002-11-01

    Using the fragmentation bomb, we analysed the effects of temperature and pressure drop on the grain-size characteristics of experimentally produced pyroclasts. Experiments performed on vesicular samples of grey dacite of the 1980 Mount St. Helens cryptodome at T=20-900 °C and initial pressure differential up to 18.5 MPa provide clear evidence of the influence of these physical conditions upon fragment size and character. Cylindrical dacite samples (diameter=17 mm, length=50 mm) are placed in the high-pressure-temperature section of the apparatus, heated and saturated by argon gas. The disruption of a diaphragm located between the high- and low-pressure sections of the apparatus initiates the rapid depressurisation of the sample. The main results may be summarised as follows. (1) Increasing temperature from 20 to 900 °C results in a decrease in the fragmentation threshold value from 9 to 3 MPa, and an increase in the median diameter of the experimental pyroclasts. These observations imply a decrease in the dynamic tensile strength of dacite at higher temperatures which in turn influences the characteristic size of fragments. (2) Increasing initial pressure differential yields a decrease of the median diameter. Thus, a higher initial elastic potential energy in the magma generates a higher degree of fragmentation. (3) Fragments of angular shape are observed from experiments at all investigated temperatures (20-900 °C), including thereby temperatures significantly higher than the classical (dilatometrically or calorimetrically determined) glass transition temperature determined for this dacite of 810 °C. Thus, brittle response of the dacite is observed under rapid decompression. (4) Fragment size distributions do not correspond to log-normal distributions and are more closely described by Rosin-Rammler distributions. With a decrease of temperature and increase of the initial pressure differential, fragment size distributions approach a Rosin-Rammler distribution

  3. Spatial trends in S and Cl in ash leachates of the May 18th, 1980 eruption of Mt. St Helens

    NASA Astrophysics Data System (ADS)

    Ayris, Paul M.; Delmelle, Pierre; Durant, Adam J.; Damby, David E.; Maters, Elena C.

    2014-05-01

    It has long been known that surficial deposits of salts and acids on volcanic ash particles derive from interactions of ash with sulphur and halide species within the eruption plume and volcanic cloud. These compounds are mobilised as ash particles are wetted, and beneficial or detrimental environmental and health impacts may be induced where the most concentrated solutions are produced. However, limited mechanistic understanding of gas-ash interactions currently precludes prediction of the spatial distribution or variation in leachate chemistry and concentration following an eruption. Sampling and leachate analysis of freshly-fallen ash therefore offers the sole method by which such variations can be observed. Previous ash leachate studies often involve a limited number of ash samples, and utilise a 'one-dimensional' analysis that considers variation in terms of absolute distance from the source volcano. Here, we demonstrate that extensive sampling and a 'two-dimensional' analysis can uncover more complex spatial trends. We compiled over 358 leachate compositions from the May 18th 1980 eruption of Mt. St. Helens. Of the water-extracted leachates, only 95 compositions from ash sampled at 45 localities between 35 and 1129 km from the volcano are sufficiently documented to be retrospectively comparable. To consider the effects of intra-deposit variability, we calculated average concentrations of leachate data within 11×22 km grid cells across the region, and defined a data quality parameter to reflect confidence in the derived values. To investigate any dependence of leachate composition on the grain size distribution, we generated an interpolated map of geometric specific surface area variation across the deposit, normalising ash leachate data to the calculated specific surface area at the corresponding sampling location. The data treatment identifies S and Cl enrichments in proximal blast deposits; relatively constant Cl concentrations across the ashfall deposits

  4. Long-term autonomous volcanic gas monitoring with Multi-GAS at Mount St. Helens, Washington, and Augustine Volcano, Alaska

    NASA Astrophysics Data System (ADS)

    Kelly, P. J.; Ketner, D. M.; Kern, C.; Lahusen, R. G.; Lockett, C.; Parker, T.; Paskievitch, J.; Pauk, B.; Rinehart, A.; Werner, C. A.

    2015-12-01

    In recent years, the USGS Volcano Hazards Program has worked to implement continuous real-time in situ volcanic gas monitoring at volcanoes in the Cascade Range and Alaska. The main goal of this ongoing effort is to better link the compositions of volcanic gases to other real-time monitoring data, such as seismicity and deformation, in order to improve baseline monitoring and early detection of volcanic unrest. Due to the remote and difficult-to-access nature of volcanic-gas monitoring sites in the Cascades and Alaska, we developed Multi-GAS instruments that can operate unattended for long periods of time with minimal direct maintenance from field personnel. Our Multi-GAS stations measure H2O, CO2, SO2, and H2S gas concentrations, are comprised entirely of commercial off-the-shelf components, and are powered by small solar energy systems. One notable feature of our Multi-GAS stations is that they include a unique capability to perform automated CO2, SO2, and H2S sensor verifications using portable gas standards while deployed in the field, thereby allowing for rigorous tracking of sensor performances. In addition, we have developed novel onboard data-processing routines that allow diagnostic and monitoring data - including gas ratios (e.g. CO2/SO2) - to be streamed in real time to internal observatory and public web pages without user input. Here we present over one year of continuous data from a permanent Multi-GAS station installed in August 2014 in the crater of Mount St. Helens, Washington, and several months of data from a station installed near the summit of Augustine Volcano, Alaska in June 2015. Data from the Mount St. Helens Multi-GAS station has been streaming to a public USGS site since early 2015, a first for a permanent Multi-GAS site. Neither station has detected significant changes in gas concentrations or compositions since they were installed, consistent with low levels of seismicity and deformation.

  5. Use of thermal infrared imaging for monitoring renewed dome growth at Mount St. Helens, 2004: Chapter 17 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

    USGS Publications Warehouse

    Schneider, David J.; Vallance, James W.; Wessels, Rick L.; Logan, Matthew; Ramsey, Michael S.; Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

    2008-01-01

    A helicopter-mounted thermal imaging radiometer documented the explosive vent-clearing and effusive phases of the eruption of Mount St. Helens in 2004. A gyrostabilized gimbal controlled by a crew member housed the radiometer and an optical video camera attached to the nose of the helicopter. Since October 1, 2004, the system has provided thermal and video observations of dome growth. Flights conducted as frequently as twice daily during the initial month of the eruption monitored rapid changes in the crater and 1980-86 lava dome. Thermal monitoring decreased to several times per week once dome extrusion began. The thermal imaging system provided unique observations, including timely recognition that the early explosive phase was phreatic, location of structures controlling thermal emissions and active faults, detection of increased heat flow prior to the extrusion of lava, and recognition of new lava extrusion. The first spines, 1 and 2, were hotter when they emerged (maximum temperature 700-730°C) than subsequent spines insulated by as much as several meters of fault gouge. Temperature of gouge-covered spines was about 200°C where they emerged from the vent, and it decreased rapidly with distance from the vent. The hottest parts of these spines were as high as 500-730°C in fractured and broken-up regions. Such temperature variation needs to be accounted for in the retrieval of eruption parameters using satellite-based techniques, as such features are smaller than pixels in satellite images.

  6. Near-real-time information products for Mount St. Helens -- tracking the ongoing eruption: Chapter 3 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

    USGS Publications Warehouse

    Qamar, Anthony I.; Malone, Stephen; Moran, Seth C.; Steele, William P.; Thelen, Weston A.; Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

    2008-01-01

    The rapid onset of energetic seismicity on September 23, 2004, at Mount St. Helens caused seismologists at the Pacific Northwest Seismic Network and the Cascades Volcano Observatory to quickly improve and develop techniques that summarized and displayed seismic parameters for use by scientists and the general public. Such techniques included webicorders (Web-based helicorder-like displays), graphs showing RSAM (real-time seismic amplitude measurements), RMS (root-mean-square) plots, spectrograms, location maps, automated seismic-event detectors, focal mechanism solutions, automated approximations of earthquake magnitudes, RSAM-based alarms, and time-depth plots for seismic events. Many of these visual-information products were made available publicly as Web pages generated and updated routinely. The graphs and maps included short written text that explained the concepts behind them, which increased their value to the nonseismologic community that was tracking the eruption. Laypeople could read online summaries of the scientific interpretations and, if they chose, review some of the basic data, thereby providing a better understanding of the data used by scientists to make interpretations about ongoing eruptive activity, as well as a better understanding of how scientists worked to monitor the volcano.

  7. Managing public and media response to a reawakening volcano: lessons from the 2004 eruptive activity of Mount St. Helens: Chapter 23 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

    USGS Publications Warehouse

    Frenzen, Peter M.; Matarrese, Michael T.; Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

    2008-01-01

    Volcanic eruptions and other infrequent, large-scale natural disturbances pose challenges and opportunities for public-land managers. In the days and weeks preceding an eruption, there can be considerable uncertainty surrounding the magnitude and areal extent of eruptive effects. At the same time, public and media interest in viewing developing events is high and concern for public safety on the part of local land managers and public safety officials is elevated. Land managers and collaborating Federal, State, and local officials must decide whether evacuations or restrictions to public access are necessary, the appropriate level of advance preparation, and how best to coordinate between overlapping jurisdictions. In the absence of a formal Federal or State emergency declaration, there is generally no identified source of supplemental funding for emergency-response preparation or managing extraordinary public and media response to developing events. In this chapter, we examine responses to escalating events that preceded the 2004 Mount St. Helens eruption and changes in public perception during the extended period of the largely nonexplosive, dome-building eruption that followed. Lessons learned include the importance of maintaining up-to-date emergency-response plans, cultivating close working relationships with collaborating agencies, and utilizing an organized response framework that incorporates clearly defined roles and responsibilities and effective communication strategies.

  8. Broadband characteristics of earthquakes recorded during a dome-building eruption at Mount St. Helens, Washington, between October 2004 and May 2005: Chapter 5 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

    USGS Publications Warehouse

    Horton, Stephen P.; Norris, Robert D.; Moran, Seth C.; Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

    2008-01-01

    From October 2004 to May 2005, the Center for Earthquake Research and Information of the University of Memphis operated two to six broadband seismometers within 5 to 20 km of Mount St. Helens to help monitor recent seismic and volcanic activity. Approximately 57,000 earthquakes identified during the 7-month deployment had a normal magnitude distribution with a mean magnitude of 1.78 and a standard deviation of 0.24 magnitude units. Both the mode and range of earthquake magnitude and the rate of activity varied during the deployment. We examined the time domain and spectral characteristics of two classes of events seen during dome building. These include volcano-tectonic earthquakes and lower-frequency events. Lower-frequency events are further classified into hybrid earthquakes, low-frequency earthquakes, and long-duration volcanic tremor. Hybrid and low-frequency earthquakes showed a continuum of characteristics that varied systematically with time. A progressive loss of high-frequency seismic energy occurred in earthquakes as magma approached and eventually reached the surface. The spectral shape of large and small earthquakes occurring within days of each other did not vary with magnitude. Volcanic tremor events and lower-frequency earthquakes displayed consistent spectral peaks, although higher frequencies were more favorably excited during tremor than earthquakes.

  9. Large-scale magnetic field perturbation arising from the 18 May 1980 eruption from Mount St. Helens, Washington

    USGS Publications Warehouse

    Mueller, R.J.; Johnston, M.J.S.

    1989-01-01

    A traveling magnetic field disturbance generated by the 18 may 1980 eruption of Mount St. Helens at 1532 UT was detected on an 800-km linear array of recording magnetometers installed along the San Andreas fault system in California, from San Francisco to the Salton Sea. Arrival times of the disturbance field, from the most northern of these 24 magnetometers (996 km south of the volcano) to the most southern (1493 km S23?? E), are consistent with the generation of a traveling ionospheric disturbance stimulated by the blast pressure wave in the atmosphere. The first arrivals at the north and the south ends of the array occurred at 26 and 48 min, respectively, after the initial eruption. Apparent average wave velocity through the array is 309 ?? 14 m s-1 but may have approached 600 m s-1 close to the volcano. The horizontal phase and the group velocity of ??? 300 m s-1 at periods of 70-80 min, and the attenuation with distance, strongly suggest that the magnetic field perturbations at distances of 1000-1500 km are caused by gravity mode acoustic-gravity waves propagating at F-region heights in the ionosphere. ?? 1989.

  10. Decadal-scale change of infiltration characteristics of a tephra-mantled hillslope at Mount St Helens, Washington

    USGS Publications Warehouse

    Major, J.J.; Yamakoshi, T.

    2005-01-01

    The cataclysmic 1980 eruption of Mount St Helens radically reduced the infiltration characteristics of ???60 000 ha of rugged terrain and dramatically altered landscape hydrology. Two decades of erosional, biogenic, cryogenic, and anthropogenic activity have modified the infiltration characteristics of much of that devastated landscape and modulated the hydrological impact of the eruption. We assessed infiltration and runoff characteristics of a segment of hillslope thickly mantled with tephra, but now revegetated primarily with grasses and other plants, to evaluate hydrological modifications due to erosion and natural turbation. Eruptive disturbance reduced infiltration capacity of the hillslope by as much as 50-fold. Between 1980 and 2000, apparent infiltration capacities of plots on the hillslope increased as much as ten fold, but remain approximately three to five times less than the probable pre-eruption capacities. Common regional rainfall intensities and snowmelt rates presently produce little surface runoff; however, high-magnitude, low-frequency storms and unusually rapid snowmelt can still induce broad infiltration-excess overland flow. After 20 years, erosion and natural mechanical turbation have modulated, but not effaced, the hydrological perturbation caused by the cataclysmic eruption. Copyright ?? 2005 John Wiley & Sons, Ltd.

  11. Generation of pyroclastic flows and surges by hot-rock avalanches from the dome of Mount St. Helens volcano, USA

    NASA Astrophysics Data System (ADS)

    Mellors, Robin A.; Waitt, Richard B.; Swanson, Donald A.

    1988-02-01

    Several hot-rock avalanches have occurred during the growth of the composite dome of Mount St. Helens, Washington between 1980 and 1987. One of these occurred on 9 May 1986 and produced a fan-shaped avalanche deposit of juvenile dacite debris together with a more extensive pyroclastic-flow deposit. Laterally thinning deposits and abrasion and baking of wooden and plastic objects show that a hot ash-cloud surge swept beyond the limits of the pyroclastic flow. Plumes that rose 2 3 km above the dome and vitric ash that fell downwind of the volcano were also effects of this event, but no explosion occurred. All the facies observed originated from a single avalanche. Erosion and melting of craterfloor snow by the hot debris caused debris flows in the crater, and a small flood that carried juvenile and other clasts north of the crater. A second, broadly similar event occured in October 1986. Larger events of this nature could present a significant volcanic hazard.

  12. Generation of pyroclastic flows and surges by hot-rock avalanches from the dome of Mount St. Helens volcano, USA

    USGS Publications Warehouse

    Mellors, R.A.; Waitt, R.B.; Swanson, D.A.

    1988-01-01

    Several hot-rock avalanches have occurred during the growth of the composite dome of Mount St. Helens, Washington between 1980 and 1987. One of these occurred on 9 May 1986 and produced a fan-shaped avalanche deposit of juvenile dacite debris together with a more extensive pyroclastic-flow deposit. Laterally thinning deposits and abrasion and baking of wooden and plastic objects show that a hot ash-cloud surge swept beyond the limits of the pyroclastic flow. Plumes that rose 2-3 km above the dome and vitric ash that fell downwind of the volcano were also effects of this event, but no explosion occurred. All the facies observed originated from a single avalanche. Erosion and melting of craterfloor snow by the hot debris caused debris flows in the crater, and a small flood that carried juvenile and other clasts north of the crater. A second, broadly similar event occured in October 1986. Larger events of this nature could present a significant volcanic hazard. ?? 1988 Springer-Verlag.

  13. Progress in Improving the Accuracy of Hugoniot Equation-of-State Measurements at the AWE Helen Laser.

    NASA Astrophysics Data System (ADS)

    Rothman, Stephen; Evans, Andrew; Graham, Peter; Horsfield, Colin

    1998-11-01

    For several years we have been conducting a series of equation-of-state (EOS) experiments using the Helen laser at AWE with the aim of an accuracy of 1% in shock velocity measurements(A.M. Evans, N.J. Freeman, P. Graham, C.J. Horsfield, S.D. Rothman, B.R. Thomas and A.J. Tyrrell, Laser and Particle Beams, vol. 14, no. 2, pp. 113-123, 1996.). Our best results to date are 1.2% in velocity on copper and aluminium double-step targets which lead to 4% in copper principal Hugoniot pressures. The accuracy in pressure depends not only on two measured shock velocities but also target density and the EOS of Al which is used here as a standard. In order to quantify sources of error and to improve accuracy we have measured the preheat-induced expansion of target surfaces using a Michelson interferometer. Analysis of streaks from this has also given reflectivity measurements. We are also investigating the use of a shaped laser pulse designed to give constant pressure for 2.5ns which will reduce the fractional errors in both step transit time and height by allowing the use of a thicker step.

  14. Rapid, low-cost photogrammetry to monitor volcanic eruptions: an example from Mount St. Helens, Washington, USA

    USGS Publications Warehouse

    Diefenbach, Angela K.; Crider, Juliet G.; Schilling, Steve P.; Dzurisin, Daniel

    2012-01-01

    We describe a low-cost application of digital photogrammetry using commercially available photogrammetric software and oblique photographs taken with an off-the-shelf digital camera to create sequential digital elevation models (DEMs) of a lava dome that grew during the 2004–2008 eruption of Mount St. Helens (MSH) volcano. Renewed activity at MSH provided an opportunity to devise and test this method, because it could be validated against other observations of this well-monitored volcano. The datasets consist of oblique aerial photographs (snapshots) taken from a helicopter using a digital single-lens reflex camera. Twelve sets of overlapping digital images of the dome taken during 2004–2007 were used to produce DEMs and to calculate lava dome volumes and extrusion rates. Analyses of the digital images were carried out using photogrammetric software to produce three-dimensional coordinates of points identified in multiple photos. The evolving morphology of the dome was modeled by comparing successive DEMs. Results were validated by comparison to volume measurements derived from traditional vertical photogrammetric surveys by the US Geological Survey Cascades Volcano Observatory. Our technique was significantly less expensive and required less time than traditional vertical photogrammetric techniques; yet, it consistently yielded volume estimates within 5% of the traditional method. This technique provides an inexpensive, rapid assessment tool for tracking lava dome growth or other topographic changes at restless volcanoes.

  15. The Effect of Consumers and Mutualists of Vaccinium membranaceum at Mount St. Helens: Dependence on Successional Context

    PubMed Central

    Yang, Suann; Jongejans, Eelke; Yang, Sylvia; Bishop, John G.

    2011-01-01

    In contrast to secondary succession, studies of terrestrial primary succession largely ignore the role of biotic interactions, other than plant facilitation and competition, despite the expectation that simplified interaction webs and propagule-dependent demographics may amplify the effects of consumers and mutualists. We investigated whether successional context determined the impact of consumers and mutualists by quantifying their effects on reproduction by the shrub Vaccinium membranaceum in primary and secondary successional sites at Mount St. Helens (Washington, USA), and used simulations to explore the effects of these interactions on colonization. Species interactions differed substantially between sites, and the combined effect of consumers and mutualists was much more strongly negative for primary successional plants. Because greater local control of propagule pressure is expected to increase successional rates, we evaluated the role of dispersal in the context of these interactions. Our simulations showed that even a small local seed source greatly increases population growth rates, thereby balancing strong consumer pressure. The prevalence of strong negative interactions in the primary successional site is a reminder that successional communities will not exhibit the distribution of interaction strengths characteristic of stable communities, and suggests the potential utility of modeling succession as the consequence of interaction strengths. PMID:22028808

  16. Using Satellite Data to Characterize the Temporal Thermal Behavior of an Active Volcano: Mount St. Helens, WA

    NASA Technical Reports Server (NTRS)

    Vaughan, R. Greg; Hook, Simon J.

    2006-01-01

    ASTER thermal infrared data over Mt. St Helens were used to characterize its thermal behavior from Jun 2000 to Feb 2006. Prior to the Oct 2004 eruption, the average crater temperature varied seasonally between -12 and 6 C. After the eruption, maximum single-pixel temperature increased from 10 C (Oct 2004) to 96 C (Aug 2005), then showed a decrease to Feb 2006. The initial increase in temperature was correlated with dome morphology and growth rate and the subsequent decrease was interpreted to relate to both seasonal trends and a decreased growth rate/increased cooling rate, possibly suggesting a significant change in the volcanic system. A single-pixel ASTER thermal anomaly first appeared on Oct 1, 2004, eleven hours after the first eruption - 10 days before new lava was exposed at the surface. By contrast, an automated algorithm for detecting thermal anomalies in MODIS data did not trigger an alert until Dec 18. However, a single-pixel thermal anomaly first appeared in MODIS channel 23 (4 um) on Oct 13, 12 days after the first eruption - 2 days after lava was exposed. The earlier thermal anomaly detected with ASTER data is attributed to the higher spatial resolution (90 m) compared with MODIS (1 m) and the earlier visual observation of anomalous pixels compared to the automated detection method suggests that local spatial statistics and background radiance data could improve automated detection methods.

  17. Temporal variation of mass-wasting activity in Mount St. Helens crater, Washington, U. S. A. indicated by seismic activity

    SciTech Connect

    Mills, H.H. )

    1991-11-01

    In the crater of Mount St. Helens, formed during the eruption of 18 May 1980, thousands of rockfalls may occur in a single day, and some rock and dirty-snow avalanches have traveled more than 1 km from their source. Because most seismic activity in the crater is produced by mass wasting, the former can be used to monitor the latter. The number and amplitude of seismic events per unit time provide a generalized measure of mass-wasting activity. In this study 1-min averages of seismic amplitudes were used as an index of rockfall activity during summer and early fall. Plots of this index show the diurnal cycle of rockfall activity and establish that the peak in activity occurs in mid to late afternoon. A correlation coefficient of 0.61 was found between daily maximum temperature and average seismic amplitude, although this value increases to 0.72 if a composite temperature variable that includes the maximum temperature of 1 to 3 preceding days as well as the present day is used. Correlation with precipitation is much weaker.

  18. Hazard information management during the autumn 2004 reawakening of Mount St. Helens volcano, Washington: Chapter 24 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

    USGS Publications Warehouse

    Driedger, Carolyn L.; Neal, Christina A.; Knappenberger, Tom H.; Needham, Deborah H.; Harper, Robert B.; Steele, William P.; Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

    2008-01-01

    The 2004 reawakening of Mount St. Helens quickly caught the attention of government agencies as well as the international news media and the public. Immediate concerns focused on a repeat of the catastrophic landslide and blast event of May 18, 1980, which remains a vivid memory for many individuals. Within several days of the onset of accelerating seismicity, media inquiries increased exponentially. Personnel at the U.S. Geological Survey, the Pacific Northwest Seismic Network, and the Gifford Pinchot National Forest soon handled hundreds of press inquiries and held several press briefings per day. About one week into the event, a Joint Information Center was established to help maintain a consistent hazard message and to provide a centralized information source about volcanic activity, hazards, area closures, and media briefings. Scientists, public-affairs specialists, and personnel from emergency-management, health, public-safety, and land-management agencies answered phones, helped in press briefings and interviews, and managed media access to colleagues working on science and safety issues. For scientists, in addition to managing the cycle of daily fieldwork, challenges included (1) balancing accurate interpretations of data under crisis conditions with the need to share information quickly, (2) articulating uncertainties for a variety of volcanic scenarios, (3) minimizing scientific jargon, and (4) frequently updating and effectively distributing talking points. Success of hazard information management during a volcanic crisis depends largely on scientists’ clarity of communication and thorough preplanning among interagency partners. All parties must commit to after-action evaluation and improvement of communication plans, incorporating lessons learned during each event.

  19. Identification and evolution of the juvenile component in 2004-2005 Mount St. Helens ash: Chapter 29 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

    USGS Publications Warehouse

    Rowe, Michael C.; Thornber, Carl R.; Kent, Adam J.R.; Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

    2008-01-01

    Petrologic studies of volcanic ash are commonly used to identify juvenile volcanic material and observe changes in the composition and style of volcanic eruptions. During the 2004-5 eruption of Mount St. Helens, recognition of the juvenile component in ash produced by early phreatic explosions was complicated by the presence of a substantial proportion of 1980-86 lava-dome fragments and glassy tephra, in addition to older volcanic fragments possibly derived from crater debris. In this report, we correlate groundmass textures and compositions of glass, mafic phases, and feldspar from 2004-5 ash in an attempt to identify juvenile material in early phreatic explosions and to distinguish among the various processes that generate and distribute ash. We conclude that clean glass in the ash is derived mostly from nonjuvenile sources and is not particularly useful for identifying the proportion of juvenile material in ash samples. High Li contents (>30 μg/g) in feldspars provide a useful tracer for juvenile material and suggest an increase in the proportion of the juvenile component between October 1 and October 4, 2004, before the emergence of hot dacite on the surface of the crater on October 11, 2004. The presence of Li-rich feldspar out of equilibrium (based on Liplagioclase/melt partitioning) with groundmass and bulk dacite early in the eruption also suggests vapor enrichment in the initially erupted dacite. If an excess vapor phase was, indeed, present, it may have provided a catalyst to initiate the eruption. Textural and compositional comparisons between dome fault gouge and the ash produced by rockfalls, rock avalanches, and vent explosions indicate that the fault gouge is a likely source of ash particles for both types of events. Comparison of the ash from vent explosions and rockfalls suggests that the fault gouge and new dome were initially heterogeneous, containing a mixture of conduit and crater debris and juvenile material, but became increasingly

  20. Absolute and relative locations of earthquakes at Mount St. Helens, Washington, using continuous data: implications for magmatic processes: Chapter 4 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

    USGS Publications Warehouse

    Thelen, Weston A.; Crosson, Robert S.; Creager, Kenneth C.; Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

    2008-01-01

    This study uses a combination of absolute and relative locations from earthquake multiplets to investigate the seismicity associated with the eruptive sequence at Mount St. Helens between September 23, 2004, and November 20, 2004. Multiplets, a prominent feature of seismicity during this time period, occurred as volcano-tectonic, hybrid, and low-frequency earthquakes spanning a large range of magnitudes and lifespans. Absolute locations were improved through the use of a new one-dimensional velocity model with excellent shallow constraints on P-wave velocities. We used jackknife tests to minimize possible biases in absolute and relative locations resulting from station outages and changing station configurations. In this paper, we show that earthquake hypocenters shallowed before the October 1 explosion along a north-dipping structure under the 1980-86 dome. Relative relocations of multiplets during the initial seismic unrest and ensuing eruption showed rather small source volumes before the October 1 explosion and larger tabular source volumes after October 5. All multiplets possess absolute locations very close to each other. However, the highly dissimilar waveforms displayed by each of the multiplets analyzed suggest that different sources and mechanisms were present within a very small source volume. We suggest that multiplets were related to pressurization of the conduit system that produced a stationary source that was highly stable over long time periods. On the basis of their response to explosions occurring in October 2004, earthquakes not associated with multiplets also appeared to be pressure dependent. The pressure source for these earthquakes appeared, however, to be different from the pressure source of the multiplets.

  1. Mount St. Helens a decade after the 1980 eruptions: magmatic models, chemical cycles, and a revised hazards assessment

    USGS Publications Warehouse

    Pallister, J.S.; Hoblitt, R.P.; Crandell, D.R.; Mullineaux, D.R.

    1992-01-01

    Available geophysical and geologic data provide a simplified model of the current magmatic plumbing system of Mount St. Helens (MSH). This model and new geochemical data are the basis for the revised hazards assessment presented here. The assessment is weighted by the style of eruptions and the chemistry of magmas erupted during the past 500 years, the interval for which the most detailed stratigraphic and geochemical data are available. This interval includes the Kalama (A. D. 1480-1770s?), Goat Rocks (A.D. 1800-1857), and current eruptive periods. In each of these periods, silica content decreased, then increased. The Kalama is a large amplitude chemical cycle (SiO2: 57%-67%), produced by mixing of arc dacite, which is depleted in high field-strength and incompatible elements, with enriched (OIB-like) basalt. The Goat Rocks and current cycles are of small amplitude (SiO2: 61%-64% and 62%-65%) and are related to the fluid dynamics of magma withdrawal from a zoned reservoir. The cyclic behavior is used to forecast future activity. The 1980-1986 chemical cycle, and consequently the current eruptive period, appears to be virtually complete. This inference is supported by the progressively decreasing volumes and volatile contents of magma erupted since 1980, both changes that suggest a decreasing potential for a major explosive eruption in the near future. However, recent changes in seismicity and a series of small gas-release explosions (beginning in late 1989 and accompanied by eruption of a minor fraction of relatively low-silica tephra on 6 January and 5 November 1990) suggest that the current eruptive period may continue to produce small explosions and that a small amount of magma may still be present within the conduit. The gas-release explosions occur without warning and pose a continuing hazard, especially in the crater area. An eruption as large or larger than that of 18 May 1980 (???0.5 km3 dense-rock equivalent) probably will occur only if magma rises from

  2. Finite Element Model of a Two-Phase Non-Newtonian Thixotropic Fluid: Mount St. Helens Lava Dome

    NASA Astrophysics Data System (ADS)

    Vincent, P.; Zevada, P.

    2011-12-01

    Extrusion of highly viscous lavas that spread laterally and form lava domes in the craters of large volcanoes is associated with significant volcanic hazards. Gas overpressure driven fragmentation of the lava dome or collapse and slumping of marginal sections or the entire mass of the dome can trigger dangerous pyroclastic flows that threaten surrounding populations up to tens of kilometers away. The rate of lava dome growth in the mature state of the dome evolution is often oscillatory. Relatively quiescent episodes are terminated by renewed extrusion and emplacement of exogenous "lobes" or "spines" of lava on the surface of the dome. Emplacement of new lobes is preceded by pressurization of magma in the magmatic conduit that can trigger volcanic eruptions and is preceded by crater floor deformation (e.g. Swanson and Holcombe, 1990). This oscillatory behavior was previously attributed primarily to crystallization kinetics and gas exsolution generating cyclic overpressure build-ups. Analogue modeling of the lava domes has revealed that the oscillatory growth rate can be reproduced by extrusion of isothermal, pseudoplastic and thixotropic plaster of Paris (analogue material for the magma) on a sand layer (analogue material for the unconsolidated deposits of the crater floor). The patterns of dome growth of these models closely correspond to both the 1980-1985 and 2004-2005 growth episodes of Mt. St. Helens lava dome (Swanson and Holcombe, 1990; Major et al., 2005). They also suggest that the oscillatory growth dynamics of the lavas can be explained by the mechanical interaction of the non-Newtonian magma with the frictional and deformable substrate below the lava dome rather than complex crystallization kinetics (e.g. Melnik and Sparks, 1999). In addition, these results suggest that the renewed growth episode of Mt. St. Helens dome in 2006 could be associated with an even higher degree of magma pressurization in the conduit than occurred during the 1980 - 1986

  3. Chronology, morphology and stratigraphy of pumiceous pyroclastic-flow (ignimbrite) deposits from the eruption of Mount St. Helens on 18 May 1983

    NASA Technical Reports Server (NTRS)

    Criswell, C. W.; Elston, W. E.

    1984-01-01

    Between 1217 and 1620 hours (PDT), on May 18, 1980, the magmatic eruption column of Mount St. Helens formed an ash fountain and pyroclastic flows dominated the eruption process over tephra ejection. Eurption-rate pulsations generally increased to a maximum at 1600 to 1700 hrs. After 1620 hrs, the eruption assumed an open-vent discharge with strong, vertical ejection of tephra. Relative eruption rates (relative mass flux rates) of the pyroclastic flows were determined by correlating sequential photographs and SLAR images, obtained during the eruption, with stratigraphy and surface morphology of the deposits.

  4. Effects of the eruptions of Mount St. Helens on physical, chemical, and biological characteristics of surface water, ground water, and precipitation in the Western United States

    USGS Publications Warehouse

    Lee, Douglas B.

    1996-01-01

    Over 120 publications that describe the 1980 eruption effects of Mount St. Helens on rivers, lakes, and the Columbia River estuary are reviewed. Water-quality changes ranged from minor, short-lived effects, to totally altered drainage basins and newly created lakes. Turbidity increased; concentrations of cations, anions, and dissolved organic carbon increased. Migrating fish were adversely affected; benthic-invertebrate populations changed. Ground-water levels rose near the Cowlitz River. Precipitation effects included transient, but increased specific conductance and decreased pH.

  5. Where is the hot rock and where is the ground water – Using CSAMT to map beneath and around Mount St. Helens

    USGS Publications Warehouse

    Wynn, Jeff; Mosbrucker, Adam; Pierce, Herbert; Spicer, Kurt R.

    2016-01-01

    We have observed several new features in recent controlled-source audio-frequency magnetotelluric (CSAMT) soundings on and around Mount St. Helens, Washington State, USA. We have identified the approximate location of a strong electrical conductor at the edges of and beneath the 2004–08 dome. We interpret this conductor to be hot brine at the hot-intrusive-cold-rock interface. This contact can be found within 50 meters of the receiver station on Spine 5, which extruded between April and July of 2005. We have also mapped separate regional and glacier-dome aquifers, which lie one atop the other, out to considerable distances from the volcano.

  6. Bayesian Inversion using Physics-based Models Applied to Dome Extrusion at Mount St. Helens 2004-2008

    NASA Astrophysics Data System (ADS)

    Wong, Y. Q.; Segall, P.; Anderson, K. R.; Bradley, A. M.

    2015-12-01

    Physics-based models of volcanic eruptions have grown more sophisticated over the past few decades. These models, combined with Bayesian inversion, offer the potential of integrating diverse geological and geophysical datasets to better understand volcanic systems. Using a Markov Chain Monte Carlo (MCMC) algorithm with a physics-based conduit model, we invert data from the 2004-2008 dome-forming eruption at Mount St. Helens, USA. We extend the 1D cylindrical conduit model of Anderson and Segall [2011] to include vertical and lateral gas loss from the magma, as well as equilibrium crystallization. The melt viscosity increases strongly with crystal content. Magma permeability obeys the Kozeny-Carman law with a threshold porosity. Excess pressure in the magma chamber drives Newtonian flow of magma upwards until the viscous resistance to flow exceeds the rate-dependent frictional strength on the conduit wall, at which point the magma transitions from viscous flow to plug flow. We investigate the steady-state solutions for lava dome growth between March and December 2005, in which magma chamber pressure, initial water content, permeability and friction parameters are unknown model parameters. These parameters are constrained by: dome rock porosity, extrusion rate from photogrammetry, plug depth from drumbeat earthquakes, and crystallization pressure from petrologic studies. Posterior probability density functions (PDFs) reveal the constraints on the model parameters and their correlations. Assuming lithostatic normal stress on the plug, low coefficients of friction (0.1-0.3) are required to allow extrusion at the observed rate while maintaining reasonable magma chamber pressures. Lower effective normal stress or melt viscosity could allow for larger friction coefficients. Future work will investigate the time-dependent system, thereby allowing us to incorporate time-evolving geodetic and eruption rate data into the inversion.

  7. Influence of particle aggregation on deposition of distal tephra from the May 18, 1980, eruption of Mount St. Helens volcano

    SciTech Connect

    Carey, S.N.; Sigurdsson, H.

    1982-08-10

    The May 18, 1980, eruption of Mount St. Helens (MSH) produced an extensive ashfall deposit in Washington, Idaho, and Montana with a minimum volume of 0.55 km/sup 3/ (tephra). An unusual feature of the deposit is the occurrence of a second thickness maximum 325 km ENE of MSH near Ritzville, Washington. Grain size and component abundance analysis of samples along the main is very fine grained (mean size, 2 ..mu..m), poorly sorted, polymodal, and rich in glass shards and pumice fragments. A computer simulation of ash fallout from an atmospherically dispersed eruption plume was developed to evaluate various hypotheses for the origin of the distal ash characteristics, particularly the thickness versus distance relationship. The model was constrained by observations of the eruption column height, elevation of major ash transport, lateral spreading of the eruption plume, and atmospheric wind structure in the vicinity of MSH. Results of different simulations indicate that the second thickness maximum cannot be attributed to either decreased wind velocities over central Washington or injection of fine ash above the horizontal wind velocity maximum near the tropopause. For the model to fit the observed characteristics of the deposit, significant particle aggregation of ash finer than 63 ..mu..m must be invoked. The best fit occurs when ash less than 63 ..mu..m is aggregated into particles several hundred microns in diameter with a settling velocity of 0.35 m/s. Support for this process comes from the observation and collection of fragile ash clusters of similar size which fell at Pullman, Washington, during the May 18 eruption (Sorem, 1982). The premature fallout of fine ash as particle aggregates is a fundamental process in the origin of the grain size characteristics, variations in component abundances, and thickness versus distance relationship of the May 18 MSH ash fall deposit.

  8. Ground-coupled acoustic airwaves from Mount St. Helens provide constraints on the May 18, 1980 eruption

    NASA Astrophysics Data System (ADS)

    Johnson, Jeffrey B.; Malone, Stephen D.

    2007-06-01

    The May 18, 1980 Mount St. Helens eruption perturbed the atmosphere and generated atmosphere-to-ground coupled airwaves, which were recorded on at least 35 seismometers operated by the Pacific Northwest Seismograph Network (PNSN). From 102 distinct travel time picks we identify coherent airwaves crossing Washington State primarily to the north and east of the volcano. The travel time curves provide evidence for both stratospheric refractions (at 200 to 300 km from the volcano) as well as probable thermospheric refractions (at 100 to 350 km). The very few first-hand reports of audible volcano sounds within about 80 km of the volcano coincide with a general absence of ground-coupled acoustic arrivals registered within about 100 km and are attributed to upward refraction of sound waves. From the coherent refracted airwave arrivals, we identify at least four distinct sources which we infer to originate 10 s, 114 s, ˜ 180 s and 319 s after the onset of an 8:32:11 PDT landslide. The first of these sources is attributed to resultant depressurization and explosion of the cryptodome. Most of the subsequent arrivals also appear to be coincident with a source located at or near the presumed volcanic conduit, but at least one of the later arrivals suggests an epicenter displaced about 9 km to the northwest of the vent. This dislocation is compatible with the direction of the sector collapse and lateral blast. We speculate that this concussion corresponds to a northern explosion event associated with hot cryptodome entering the Toutle River Valley.

  9. Duration of exposure--histological effects on broiler lungs, performance, and house environment with Mt. St. Helens volcanic ash dust

    SciTech Connect

    Bland, M.C.; Nakaue, H.S.; Goeger, M.P.; Helfer, D.H.

    1985-01-01

    Fourteen hundred broilers were exposed to Mt. St. Helens volcanic ash (VA) dust (D) from 28 to 49 days of age to correlate the duration of exposure time to histological effect on lungs and to determine the effects on broiler performance and house environment. Histological examinations of the lungs from birds exposed each day for 4 days to either VAD for 60 min (VAD 60) in the morning and afternoon (3276 g VA/day), or VAD after one direct application (DiAp) (20 kg/m2) on wood shaving litter revealed mild lymphoid hyperplasia and granuloma formation accompanied by phagocytized crystalline material seen in some alveolar macrophages; however, no effect was observed in lung tissues from broilers exposed each day for 4 days to VAD for 15 min (VAD 15) in the morning and afternoon (82 g VAD/day). Birds exposed to all VAD treatments and examined after 7 days had histological changes in the lungs, including giant cell granuloma formation, similar to those seen at 4 days. No significant histopathological changes were found in the turbinates with any VAD treatments. Levels of mean body weight, ammonia concentration, mortality, and respiratory dust (particles ranging in size from .5 to 10 micron) levels were not significantly different among the treatments. Significantly poorer mean feed conversion was observed with broilers exposed to VAD 60 than the VA DiAp exposure. No difference in feed conversion was observed between the control and either VAD 15 or VAD 60 treatments. From this experiment, the observed histological changes in the lungs occurred with 4 days or less exposure to VAD 60 (3276 g/day).

  10. Genetic structure among coastal tailed frog populations at Mount St. Helens is moderated by post-disturbance management.

    PubMed

    Spear, Stephen F; Crisafulli, Charles M; Storfer, Andrew

    2012-04-01

    Catastrophic disturbances often provide "natural laboratories" that allow for greater understanding of ecological processes and response of natural populations. The 1980 eruption of the Mount St. Helens volcano in Washington, USA, provided a unique opportunity to test biotic effects of a large-scale stochastic disturbance, as well as the influence of post-disturbance management. Despite severe alteration of nearly 600 km2 of habitat, coastal tailed frogs (Ascaphus truei) were found within a portion of the blast area five years after eruption. We investigated the genetic source of recolonization within the blast area and tested whether post-eruption salvage logging and subsequent tree planting influenced tailed frog movement patterns. Our results support widespread recolonization across the blast area from multiple sources, as all sites are grouped into one genetic cluster. Landscape genetic models suggest that gene flow through the unmanaged portion of the blast area is influenced only by distance between sites and the frost-free period (r2 = 0.74). In contrast, gene flow pathways within the blast area where salvage logging and replanting occurred post-eruption are strongly limited (r2 = 0.83) by the physiologically important variables of heat load and precipitation. These data suggest that the lack of understory and coarse wood (downed and standing dead tree boles) refugia in salvaged areas may leave frogs more susceptible to desiccation and mortality than those frogs moving through the naturally regenerated area. Simulated populations based on the landscape genetic models show an increase in the inbreeding coefficient in the managed area relative to the unmanaged blast area. In sum, we show surprising resilience of an amphibian species to a catastrophic disturbance, and we suggest that, at least for this species, naturally regenerating habitat may better maintain long-term genetic diversity of populations than actively managed habitat.

  11. The Stars Belong to Everyone: The rhetorical practices of astronomer and science writer Dr. Helen Sawyer Hogg (1905--1993)

    NASA Astrophysics Data System (ADS)

    Cahill, Maria J.

    Astronomer and science writer Dr. Helen Sawyer Hogg (University of Toronto) reached a variety of audiences through different rhetorical forms. She communicated to her colleagues through her scholarly writings; she reached out to students and the public through her Toronto Star newspaper column entitled "With the Stars," which she authored for thirty years; she wrote The Stars Belong to Everyone , a book that speaks to a lay audience; she hosted a successful television series entitled Ideas ; and she delivered numerous speeches at scientific conferences, professional women's associations, school programs, libraries, and other venues. Adapting technical information for different audiences is at the heart of technical communication, and Sawyer Hogg's work exemplifies adaptation as she moves from writing for the scientific community (as in her articles on globular cluster research) to science writing for lay audiences (as in her newspaper column, book, and script for her television series). Initially she developed her sense of audience through a male perspective informed largely by her scholarly work with two men (Harlow Shapley and her husband, Frank Hogg) as well as the pervasive masculine culture of academic science. This dissertation situates Sawyer Hogg in what is slowly becoming a canon of technical communication scholarship on female scientists. Toward this end, I discuss how she rhetorically engaged two different audiences, one scholarly and one popular, how Sawyer Hogg translated male dominated scientific rhetoric to writing for the public, and how science writing helped her achieve her professional goals. Complementing the archival research in addressing the questions of this study, I employ social construction analysis (also known as the social perspective) for my research methodology. She was ahead of her time and embodied the social perspective years before its definition as a rhetorical concept. In short, my study illuminates one scientific woman's voice

  12. Eruption dynamics at Mount St. Helens imaged from broadband seismic waveforms: Interaction of the shallow magmatic and hydrothermal systems

    USGS Publications Warehouse

    Waite, G.P.; Chouet, B.A.; Dawson, P.B.

    2008-01-01

    The current eruption at Mount St. Helens is characterized by dome building and shallow, repetitive, long-period (LP) earthquakes. Waveform cross-correlation reveals remarkable similarity for a majority of the earthquakes over periods of several weeks. Stacked spectra of these events display multiple peaks between 0.5 and 2 Hz that are common to most stations. Lower-amplitude very-long-period (VLP) events commonly accompany the LP events. We model the source mechanisms of LP and VLP events in the 0.5-4 s and 8-40 s bands, respectively, using data recorded in July 2005 with a 19-station temporary broadband network. The source mechanism of the LP events includes: 1) a volumetric component modeled as resonance of a gently NNW-dipping, steam-filled crack located directly beneath the actively extruding part of the new dome and within 100 m of the crater floor and 2) a vertical single force attributed to movement of the overlying dome. The VLP source, which also includes volumetric and single-force components, is 250 m deeper and NNW of the LP source, at the SW edge of the 1980s lava dome. The volumetric component points to the compression and expansion of a shallow, magma-filled sill, which is subparallel to the hydrothermal crack imaged at the LP source, coupled with a smaller component of expansion and compression of a dike. The single-force components are due to mass advection in the magma conduit. The location, geometry and timing of the sources suggest the VLP and LP events are caused by perturbations of a common crack system.

  13. Heating of buried layer targets by 1φ and 2φ pulses using the HELEN CPA laser

    NASA Astrophysics Data System (ADS)

    Thornton, Lee; Hoarty, David

    2007-11-01

    Targets of plastic with a buried layer of aluminum at different depths were heated using the HELEN CPA laser which irradiated one surface. The emission spectra from the Al were used to infer the conditions in the target by comparing the measured spectra against those generated by the FLY code (whose input was the temperature and density history calculated by a radiation-hydrodynamics code iterated to achieve the best match to the experimental data). Measurements were taken at both a laser wavelength of 1.06 μm and after conversion to 0.53 μm. The laser irradiance was varied between 2 x 10^17 - 10^19 W/cm^2 by altering the laser pulselength, energy and wavelength. The data show the plastic target was heated above 200eV to a depth of about 4μm with 1.06 μm P-polarised light. The FLY comparisons indicate the buried layers heated with 0.53 μm light remained near solid density for the duration of the X-ray emission pulse and achieved a peak temperature of 500±50eV. In the case where the target was heated with 1.06 μm radiation, the density was an order of magnitude lower and the peak temperature achieved was also lower at 320±50eV. The depth to which the target was heated was similar at the two wavelengths for 0.5ps pulses. In further measurements using 0.53 μm light at similar energies (but using pulses with a FWHM of 2 ps), heating to greater than 200eV was observed to a depth of 8 μm.

  14. Heating of buried layer targets by 1 ω and 2 ω pulses using the HELEN CPA laser

    NASA Astrophysics Data System (ADS)

    Hoarty, D. J.; James, S. F.; Davies, H.; Brown, C. R. D.; Harris, J. W. O.; Smith, C. C.; Davidson, S. J.; Kerswill, E.; Crowley, B. J. B.; Rose, S. J.

    2007-05-01

    Targets of plastic with a buried layer of aluminium were heated using the HELEN CPA laser to irradiate one surface of the plastic. The emission spectra from the aluminium were used to infer the conditions in the target by comparing the measured spectra against synthetic spectra generated by the FLY code. The input to the FLY code was the temperature and density history calculated by a radiation-hydrodynamics code, which was iterated to achieve the best match to the experimental data. Aluminium layers at different depths in the plastic were used to measure how heat was transported into the target. Measurements were taken with the laser at wavelengths of 1.06 μm and wavelength converted to 0.53 μm. The laser irradiance was varied between 2 × 10 17-10 19 W/cm 2 by varying the laser pulse length, energy and wavelength. The data show that the plastic target was heated above 200 eV to a depth of about 4 μm. The FLY comparisons indicate that the buried layers heated with 0.53 μm light remained near solid density for the duration of the X-ray emission pulse and achieved a peak temperature of 450 ± 50 eV. In the case where the target was heated with 1.06 μm radiation, the density was an order of magnitude lower and the peak temperature achieved was also substantially lower, at 320 ± 50 eV. The depth to which the target was heated was similar at the two wavelengths studied and was not a strong function of irradiance. The aluminium data are presented and compared to radiation-hydrodynamic and spectral modelling.

  15. After the disaster: the hydrogeomorphic, ecological, and biological responses to the 1980 eruption of Mount St. Helens, Washington

    USGS Publications Warehouse

    Major, Jon J.; Crisafulli, Charlie; Bishop, John

    2009-01-01

    The 1980 eruption of Mount St. Helens caused instantaneous landscape disturbance on a grand scale. On 18 May 1980, an ensemble of volcanic processes, including a debris avalanche, a directed pyroclastic density current, voluminous lahars, and widespread tephra fall, abruptly altered landscape hydrology and geomorphology, and created distinctive disturbance zones having varying impacts on regional biota. Response to the geological and ecological disturbances has been varied and complex. In general, eruption-induced alterations in landscape hydrology and geomorphology led to enhanced stormflow discharge and sediment transport. Although the hydrological response to landscape perturbation has diminished, enhanced sediment transport persists in some basins. In the nearly 30 years since the eruption, 350 million (metric) tons of suspended sediment has been delivered from the Toutle River watershed to the Cowlitz River (roughly 40 times the average annual preeruption suspended-sediment discharge of the Columbia River). Such prodigious sediment loading has wreaked considerable socioeconomic havoc, causing significant channel aggradation and loss of flood conveyance capacity. Significant and ongoing engineering efforts have been required to mitigate these problems. The overall biological evolution of the eruption-impacted landscape can be viewed in terms of a framework of survivor legacies. Despite appearances to the contrary, a surprising number of species survived the eruption, even in the most heavily devastated areas. With time, survivor “hotspots” have coalesced into larger patches, and have served as stepping stones for immigrant colonization. The importance of biological legacies will diminish with time, but the intertwined trajectories of geophysical and biological successions will influence the geological and biological responses to the 1980 eruption for decades to come.

  16. The controls and consequences of substrate entrainment by pyroclastic density currents at Mount St Helens, Washington (USA)

    NASA Astrophysics Data System (ADS)

    Pollock, N. M.; Brand, B. D.; Roche, O.

    2016-10-01

    Evidence in the deposits from the May 18, 1980 eruption at Mount St Helens demonstrates that pyroclastic density currents (PDCs) produced during the afternoon of the eruption became intermittently erosive. Using detailed componentry and granulometry we constrain the sources for lithic blocks in the deposits and identify deposits from PDCs that became locally erosive. The componentry of the lithics in the fall deposits is used as a proxy for vent erosion and assumed to represent the starting componentry for PDCs prior to entrainment from any other source. We find little evidence in the PDC deposits nearest to the base of the volcano for entrainment from the steep flanks; however, significant evidence indicates that PDCs eroded into the debris avalanche hummocks, suggesting that entrainment is favored as PDCs interact with highly irregular topography. Evidence for locally entrained material downstream from debris avalanche hummocks decreases with height in the outcrop, suggesting that less entrainment occurs as local relief decreases and upstream topography is buried. The prevalence of lithofacies containing locally entrained material at the base of unit contacts and only 10s of meters downstream from debris avalanche hummocks suggests that the majority of entrainment occurs at or near the head of the current. Occasionally, entrained material is located high above unit contacts and deposited well after the initial head of the current is inferred to have passed, indicating that entrainment can occur during periods of non-deposition either from the semi-sustained body of the current or from a pulsating current. Additionally, self-channelization of PDCs, either by levee deposition or scouring into earlier PDC deposits, occurs independently of interaction with topographic obstacles and can affect carrying capacity and runout distance. While we begin to explore the mechanisms and effects of erosion on current dynamics, additional laboratory and numerical studies are

  17. Ground-coupled acoustic airwaves from Mount St. Helens provide constraints on the May 18, 1980 eruption

    USGS Publications Warehouse

    Johnson, J.B.; Malone, S.D.

    2007-01-01

    The May 18, 1980 Mount St. Helens eruption perturbed the atmosphere and generated atmosphere-to-ground coupled airwaves, which were recorded on at least 35 seismometers operated by the Pacific Northwest Seismograph Network (PNSN). From 102 distinct travel time picks we identify coherent airwaves crossing Washington State primarily to the north and east of the volcano. The travel time curves provide evidence for both stratospheric refractions (at 200 to 300 km from the volcano) as well as probable thermospheric refractions (at 100 to 350 km). The very few first-hand reports of audible volcano sounds within about 80 km of the volcano coincide with a general absence of ground-coupled acoustic arrivals registered within about 100 km and are attributed to upward refraction of sound waves. From the coherent refracted airwave arrivals, we identify at least four distinct sources which we infer to originate 10 s, 114 s, ∼ 180 s and 319 s after the onset of an 8:32:11 PDT landslide. The first of these sources is attributed to resultant depressurization and explosion of the cryptodome. Most of the subsequent arrivals also appear to be coincident with a source located at or near the presumed volcanic conduit, but at least one of the later arrivals suggests an epicenter displaced about 9 km to the northwest of the vent. This dislocation is compatible with the direction of the sector collapse and lateral blast. We speculate that this concussion corresponds to a northern explosion event associated with hot cryptodome entering the Toutle River Valley.

  18. Cooling rate and thermal structure determined from progressive magnetization of the Dacite Dome at Mount St. Helens, Washington

    NASA Astrophysics Data System (ADS)

    Dzurisin, Daniel; Denlinger, Roger P.; Rosenbaum, Joseph G.

    1990-03-01

    Our study of a magnetic anomaly associated with the recently active dacite dome at Mount St. Helens suggests that the dome consists of a hot, nonmagnetized core surrounded by a cool, magnetized carapace and flanking talus. The talus does not contribute to the anomaly because its constituent blocks are randomly oriented. Temporal changes in the magnetic anomaly indicate that the magnetized carapace thickened at an average rate of 0.03±0.01 m/d from 1984 to 1986. Petrographic and rock magnetic properties of dome samples indicate that the dominant process responsible for these changes is magnetization of extensively oxidized rock at progressively deeper levels within the dome as the rock cools through its blocking temperature, rather than subsequent changes in magnetization caused by further oxidation. Newly extruded material cools rapidly for a short period as heat is conducted outward in response to convective heat loss from its surface. The cooling rate gradually declines for several weeks, and thereafter the material cools at a relatively constant rate by convective heat loss from its interior along fractures that propagate inward. The rate of internal convective heat loss through fractures varies with rainfall, snowmelt, and large-scale fracturing during subsequent eruptive episodes. In accordance with a model for solidification of the 1959 lava lake at Kilauea Iki, Hawaii, we picture the dome's magnetized carapace as being a two-phase, porous, convective zone separated from the nonmagnetized core of the dome by a thin, single-phase conductive zone. As a consequence of the heat balance between the conductive and convective zones, the blocking-temperature isotherm migrates inward at a relatively constant rate. If the dome remains inactive, the time scale for its complete magnetization is estimated to be 18-36 years, a forecast which can be refined by shallow drilling into the dome and by continuing studies of its growing magnetic anomaly.

  19. Monitoring lava-dome growth during the 2004-2008 Mount St. Helens, Washington, eruption using oblique terrestrial photography

    USGS Publications Warehouse

    Major, J.J.; Dzurisin, D.; Schilling, S.P.; Poland, Michael P.

    2009-01-01

    We present an analysis of lava dome growth during the 2004–2008 eruption of Mount St. Helens using oblique terrestrial images from a network of remotely placed cameras. This underutilized monitoring tool augmented more traditional monitoring techniques, and was used to provide a robust assessment of the nature, pace, and state of the eruption and to quantify the kinematics of dome growth. Eruption monitoring using terrestrial photography began with a single camera deployed at the mouth of the volcano's crater during the first year of activity. Analysis of those images indicates that the average lineal extrusion rate decayed approximately logarithmically from about 8 m/d to about 2 m/d (± 2 m/d) from November 2004 through December 2005, and suggests that the extrusion rate fluctuated on time scales of days to weeks. From May 2006 through September 2007, imagery from multiple cameras deployed around the volcano allowed determination of 3-dimensional motion across the dome complex. Analysis of the multi-camera imagery shows spatially differential, but remarkably steady to gradually slowing, motion, from about 1–2 m/d from May through October 2006, to about 0.2–1.0 m/d from May through September 2007. In contrast to the fluctuations in lineal extrusion rate documented during the first year of eruption, dome motion from May 2006 through September 2007 was monotonic (± 0.10 m/d) to gradually slowing on time scales of weeks to months. The ability to measure spatial and temporal rates of motion of the effusing lava dome from oblique terrestrial photographs provided a significant, and sometimes the sole, means of identifying and quantifying dome growth during the eruption, and it demonstrates the utility of using frequent, long-term terrestrial photography to monitor and study volcanic eruptions.

  20. The 18 May 1980 eruption of Mount St. Helens: The nature of the eruption, with an atmospheric perspective

    NASA Technical Reports Server (NTRS)

    Rose, W. I., Jr.; Hoffman, M. F.

    1982-01-01

    Mount St. Helens erupted somewhat less than 0.5 cu km of magma (dense rock equivalent) on May 18, 1980. The May 18 event was usually violent. As much 35% of the volume of the airfall material fell outside of the 2.5 mm isopach, which encloses about 88,000 sq km. This extraordinary dispersive power was transmitted by an eruption column which reached heights of more than 20 km. There was a lateral blast (or surge) of unusually large dimensions associated with the onset of the eruption. The magma is dacitic in composition and had a low ( 500 ppm) sulfur content. Distal ashes contain much nonmagmatic (lithic) material, but smaller ( 50 microns m) particles are mostly finely divided magmatic dacite. The grain size distributions of the ash are multimodal, frequently with peaks at 90, 25, and 10 microns. The finer populations fell out faster than their terminal velocities as simple particles would suggest. It is inferred that large proportions of the fine ash fell out as composite particles. This condition greatly reduces the atmospheric burden of silicate particles. Some of the unusual aspects (violence, intense surges, multimodal grain size distributions, lithic content of the ashes) of the eruption may be due to its phreatomagmatic character. The hydrothermal system above the magma may have infiltrated the magma body at the onset of the eruption. An "overprint" of the geochemistry of this hydrothermal system on the geochemistry of the magmatic gas system is likely. One important feature is that reduced gas species may be much more abundant than in many eruptions. Another is that fine ash may form aggregates more readily.

  1. Genetic structure among coastal tailed frog populations at Mount St. Helens is moderated by post-disturbance management.

    PubMed

    Spear, Stephen F; Crisafulli, Charles M; Storfer, Andrew

    2012-04-01

    Catastrophic disturbances often provide "natural laboratories" that allow for greater understanding of ecological processes and response of natural populations. The 1980 eruption of the Mount St. Helens volcano in Washington, USA, provided a unique opportunity to test biotic effects of a large-scale stochastic disturbance, as well as the influence of post-disturbance management. Despite severe alteration of nearly 600 km2 of habitat, coastal tailed frogs (Ascaphus truei) were found within a portion of the blast area five years after eruption. We investigated the genetic source of recolonization within the blast area and tested whether post-eruption salvage logging and subsequent tree planting influenced tailed frog movement patterns. Our results support widespread recolonization across the blast area from multiple sources, as all sites are grouped into one genetic cluster. Landscape genetic models suggest that gene flow through the unmanaged portion of the blast area is influenced only by distance between sites and the frost-free period (r2 = 0.74). In contrast, gene flow pathways within the blast area where salvage logging and replanting occurred post-eruption are strongly limited (r2 = 0.83) by the physiologically important variables of heat load and precipitation. These data suggest that the lack of understory and coarse wood (downed and standing dead tree boles) refugia in salvaged areas may leave frogs more susceptible to desiccation and mortality than those frogs moving through the naturally regenerated area. Simulated populations based on the landscape genetic models show an increase in the inbreeding coefficient in the managed area relative to the unmanaged blast area. In sum, we show surprising resilience of an amphibian species to a catastrophic disturbance, and we suggest that, at least for this species, naturally regenerating habitat may better maintain long-term genetic diversity of populations than actively managed habitat. PMID:22645816

  2. Swift snowmelt and floods (lahars) caused by great pyroclastic surge at Mount St Helens volcano, Washington, 18 May 1980

    USGS Publications Warehouse

    Waitt, R.B.

    1989-01-01

    The initial explosions at Mount St. Helens, Washington, on the moring of 18 May 1980 developed into a huge pyroclastic surge that generated catastrophic floods off the east and west flanks of the volcano. Near-source surge deposits on the east and west were lithic, sorted, lacking in accretionary lapilli and vesiculated ash, not plastered against upright obstacles, and hot enough to char wood - all attributes of dry pyroclastic surge. Material deposited at the surge base on steep slopes near the volcano transformed into high-concentration lithic pyroclastic flows whose deposits contain charred wood and other features indicating that these flows were hot and dry. Stratigraphy shows that even the tail of the surge had passed the east and west volcano flanks before the geomorphically distinct floods (lahars) arrived. This field evidence undermines hypotheses that the turbulent surge was itself wet and that its heavy components segregated out to transform directly into lahars. Nor is there evidence that meters-thick snow-slab avalanches intimately mixed with the surge to form the floods. The floods must have instead originated by swift snowmelt at the base of a hot and relatively dry turbulent surge. Impacting hot pyroclasts probably transferred downslope momentum to the snow surface and churned snow grains into the surge base. Melting snow and accumulating hot surge debris may have moved initially as thousands of small thin slushflows. As these flows removed the surface snow and pyroclasts, newly uncovered snow was partly melted by the turbulent surge base; this and accumulating hot surge debris in turn began flowing, a self-sustaining process feeding the initial flows. The flows thus grew swiftly over tens of seconds and united downslope into great slushy ejecta-laden sheetfloods. Gravity accelerated the floods to more than 100 km/h as they swept down and off the volcano flanks while the snow component melted to form great debris-rich floods (lahars) channeled into

  3. A glacier peak and Mount Saint Helens J volcanic ash couplet and the timing of deglaciation in the Colville Valley area, Washington

    USGS Publications Warehouse

    Carrara, P.E.; Trimble, D.A.

    1992-01-01

    A Late Pleistocene volcanic ash couplet consisting of a glacier Peak ash layer and an underlying Mount Saint Helens J ash layer has been identified at three sites in the Colville Valley area of northeastern Washington. This ash couplet has been reported as far east as northwestern Montana and therefore appears to have widespread distribution south of the International Boundary. Because areas covered by the Cordilleran Ice Sheet, as well as by local mountain glaciers and icefields, were undergoing extensive deglaciation when these ash layers were deposited, about 11 200 BP, the ash couplet is an important time-stratigraphic marker, and its identification at a site provides information about the extent of deglaciation at that time. The presence of the Glacier Peak and Mount Saint Helens J ash couplet in the Colville Valley, about 50km north (upglacier) from the Late Wisconsin terminal moraine near the town of Springdale, indicates that the active margin of the Colville sublobe of the Cordilleran Ice Sheet had retreated at least that distance by 11 200 BP. -from Authors

  4. Dynamics of seismogenic volcanic extrusion resisted by a solid surface plug, Mount St. Helens, 2004-2005: Chapter 21 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

    USGS Publications Warehouse

    Iverson, Richard M.; Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

    2008-01-01

    The 2004-5 eruption of Mount St. Helens exhibited sustained, near-equilibrium behavior characterized by nearly steady extrusion of a solid dacite plug and nearly periodic occurrence of shallow earthquakes. Diverse data support the hypothesis that these earthquakes resulted from stick-slip motion along the margins of the plug as it was forced incrementally upward by ascending, solidifying, gas-poor magma. I formalize this hypothesis with a mathematical model derived by assuming that magma enters the base of the eruption conduit at a steady rate, invoking conservation of mass and momentum of the magma and plug, and postulating simple constitutive equations that describe magma and conduit compressibilities and friction along the plug margins. Reduction of the model equations reveals a strong mathematical analogy between the dynamics of the magma-plug system and those of a variably damped oscillator. Oscillations in extrusion velocity result from the interaction of plug inertia, a variable upward force due to magma pressure, and a downward force due to the plug weight. Damping of oscillations depends mostly on plug-boundary friction, and oscillations grow unstably if friction exhibits rate weakening similar to that observed in experiments. When growth of oscillations causes the extrusion rate to reach zero, however, gravity causes friction to reverse direction, and this reversal instigates a transition from unstable oscillations to self-regulating stick-slip cycles. The transition occurs irrespective of the details of rate-weakening behavior, and repetitive stick-slip cycles are, therefore, robust features of the system’s dynamics. The presence of a highly compressible elastic driving element (that is, magma containing bubbles) appears crucial for enabling seismogenic slip events to occur repeatedly at the shallow earthquake focal depths (8 N. These results imply that the system’s self-regulating behavior is not susceptible to dramatic change--provided that the

  5. The Sedimentology of Pyroclastic Flow Lift-Off: The 18 May 1980 Mt. St. Helens Singe Zone Deposit

    NASA Astrophysics Data System (ADS)

    Dennen, R. L.; Gardner, J. E.; Befus, K. S.

    2014-12-01

    Pyroclastic density currents (PDCs) reverse buoyancy to form buoyant plumes after sufficient entrainment and heating of ambient atmosphere and deposition of suspended sediment. The deposits associated with buoyancy reversal depend on input from the feeding flow. It is expected that fines are swept away by the buoyant plume, and coarse sediment might be deposited preferentially during reversal; in an extreme case, one might expect deposit thickening at the point of buoyancy reversal as the coarse sediment rains out of the lofting plume. Alternatively, a thinner, finer grained deposit would be expected from a flow that deposited the bulk of its coarse sediment load prior to buoyancy reversal. The PDC associated with the 18 May 1980 Mt. St. Helens lateral blast downed trees as it traversed the ground (blowdown zone); at the distal extent of the blowdown zone, trees were burned, yet remained standing, in an area thought to represent a well-constrained case of PDC buoyancy reversal (singe zone). We present a sedimentological analysis of preserved deposits from the blowdown and singe zones to investigate this transition. The PDC deposit is poorly sorted, gray, sandy ash, generally <15 cm thick, and is locally normally graded. The unit includes lapilli sized clasts, with fragments of pumice, lithics, and, locally, wood fragments. Flow velocities at the blowdown/singe zone transition varied by a factor of ~2, and, where the flow velocities were slower, deceleration occurred within the blowdown zone prior to lift-off. In the singe zone, the deposit is structureless, and thins from <10 cm to <5 cm thick over a distance of 0.5-1 km. The grain-size distribution and sorting of the unit within the singe zone is broadly similar to deposits in the blowdown zone, but either become better sorted where deceleration in the blowdown zone preceded lift-off, or fine at the point of lift-off before becoming fines poor further downstream. These data indicate that the flow experienced only

  6. A closer look at the pyroclastic density current deposits of the May 18, 1980 eruption of Mt St Helens

    NASA Astrophysics Data System (ADS)

    Mackaman-Lofland, C. A.; Brand, B. D.; Dufek, J.

    2010-12-01

    Pyroclastic Density Currents (PDCs) are the most dangerous hazard associated with explosive volcanic eruptions. Due to the danger associated with observing these ground-hugging currents of searing hot gas, ash, and rock in real time, their processes are poorly understood. In order to understand flow dynamics, including what controls how far PDCs travel and how they interact with topography, it is necessary to study their deposits. The May 18th, 1980 eruption of Mt. St. Helens produced multiple PDCs, burying the area north of the volcano under 10s of meters of PDC deposits. Because the eruption is one of the best observed on record, individual flow units can be correlated to changes in eruptive intensity throughout the day (e.g., Criswell, 1987). Deep drainage erosion over the past 30 years has exposed the three-dimensional structure of the PDC deposits, making this intensive study possible. Up to six flow units have been identified along the large western drainage of the pumice plain. Each flow unit has intricate vertical and lateral facies changes and complex cross-cutting relationships away from source. The most proximal PDC deposits associated with the afternoon flows on May 18 are exposed 4 km from source in tributaries of the large drainage on the western side of the pumice plain. Hummocks from the debris avalanche are also exposed above and within these proximal drainages. It is apparent that the PDCs were often erosional, entraining large blocks from the hummocks and depositing them in close proximity downstream. The currents were also depositional, as thick sequences of PDC deposits are found in areas between hummocks, which thin to veneers above them. This indicates that the currents were interacting with complex topography early in their propagation, and is reflected by spatially variable bed conditions including rapid changes in bedding and granulometry characteristics within individual flow units. For example, within 20 lateral meters of a given flow

  7. Subevents of long-period seismicity: implications for hydrothermal dynamics during the 2004-2008 eruption of Mount St. Helens

    USGS Publications Warehouse

    Matoza, Robin S.; Chouet, Bernard A.

    2010-01-01

    One of the most striking aspects of seismicity during the 2004–2008 eruption of Mount St. Helens (MSH) was the precise regularity in occurrence of repetitive long-period (LP) or “drumbeat” events over sustained time periods. However, this precise regularity was not always observed, and at times the temporal occurrence of LP events became more random. In addition, accompanying the dominant LP class of events during the 2004–2008 MSH eruption, there was a near-continuous, randomly occurring series of smaller seismic events. These subevents are not always simply small-amplitude versions of the dominant LP class of events but appear instead to result from a separate random process only loosely coupled to the main LP source mechanism. We present an analysis of the interevent time and amplitude distributions of the subevents, using waveform cross correlation to separate LP events from the subevents. We also discuss seismic tremor that accompanied the 8 March 2005 phreatic explosion event at MSH. This tremor consists of a rapid succession of LPs and subevents triggered during the explosion, in addition to broadband noise from the sustained degassing. Immediately afterward, seismicity returned to the pre-explosion occurrence pattern. This triggering in relation to the rapid ejection of steam from the system, and subsequent return to pre-explosion seismicity, suggests that both seismic event types originated in a region of the subsurface hydrothermal system that was (1) in contact with the reservoir feeding the 8 March 2005 phreatic explosion but (2) not destroyed or drained by the explosion event. Finally, we discuss possible thermodynamic conditions in a pressurized hydrothermal crack that could give rise to seismicity. Pressure drop estimates for typical LP events are not generally large enough to perturb pure water in a shallow hydrothermal crack into an unstable state. However, dissolved volatiles such as CO2 may lead to a more unstable system, increasing the

  8. Topographic controls on pyroclastic density current dynamics: Insight from 18 May 1980 deposits at Mount St. Helens, Washington (USA)

    NASA Astrophysics Data System (ADS)

    Brand, Brittany D.; Bendaña, Sylvana; Self, Stephen; Pollock, Nicholas

    2016-07-01

    Our ability to interpret the deposits of pyroclastic density currents (PDCs) is critical for understanding the transport and depositional processes that control PDC dynamics. This paper focuses on the influence of slope on flow dynamics and criticality as recorded in PDC deposits from the 18 May 1980 eruption of Mt. St. Helens (USA). PDC deposits are found along the steep flanks (10°-30°) and across the pumice plain (~ 5°) up to 8 km north of the volcano. Granulometry, componentry and descriptions of depositional characteristics (e.g., bedform morphology) are recorded with distance from source. The pumice plain deposits are primarily thick (3-12 m), massive and poorly-sorted, and represent deposition from a series of concentrated PDCs. By contrast, the steep flank deposits are stratified to cross-stratified, suggesting deposition from PDCs where turbulence strongly influenced transport and depositional processes. We propose that acceleration of the concentrated PDCs along the steep flanks resulted in thinning of the concentrated, basal region of the current(s). Enhanced entrainment of ambient air, and autofluidization from upward fluxes of air from substrate interstices and plunging breakers across rugged, irregular topography further inflated the currents to the point that the overriding turbulent region strongly influenced transport and depositional mechanisms. Acceleration in combination with partial confinement in slot canyons and high surface roughness would also increase basal shear stress, further promoting shear and traction transport in the basal region of the current. Conditions along the steep flank resulted in supercritical flow, as recorded by regressive bedforms, which gradually transitioned to subcritical flow downstream as the concentrated basal region thickness increased as a function of decreasing slope and flow energy. We also find that (1) PDCs were erosive into the underlying granular substrate along high slopes (> 25°) where currents were

  9. Extreme events and geomorphic resilience-insight from response to the cataclysmic 1980 Mount St. Helens eruption

    NASA Astrophysics Data System (ADS)

    Major, J. J.

    2003-12-01

    Extreme geomorphic events affect sediment transfer, landform development, and landscape evolution in mountain environments. Less understood are the magnitude and persistence of geomorphic responses to extreme events and the impacts those events have on various geomorphic regimes. Generally, states of geomorphic disequilibrium caused by extreme as well as by lesser events are transient. Periods of geomorphic response to extreme events, however, can range from years to millennia; defining recovery and resilience of geomorphic systems, and thus the long-term impact of an extreme event, depends upon spatial scale and the geomorphic regime (e.g., sediment transport, water discharge, or their associated relationship) examined. Varying geomorphic-regime responses are highlighted by post-eruption responses to the 1980 Mount St. Helens (MSH) eruption. The cataclysmic 1980 MSH eruption altered runoff and abruptly increased sediment supply in several watersheds. In basins ranging in area from 300-1300 km2, post-eruption peakflow discharges increased by tens of percent for at least 5, and perhaps as long as 20, years. Post-eruption infiltration capacity quickly recovered a substantial proportion of pre-eruption capacity, predominant overland flow diminished rapidly, and runoff conditions approached a pre-eruption state. In comparison, post-eruption suspended-sediment yields increased by a much greater proportion, and have persisted much longer, than increased water discharges. Annual yields as much as 500 times greater than pre-eruption values were measured shortly after the eruption, and yields 10-100 times greater than pre-eruption values persist. Magnitudes and durations of post-eruption sediment delivery have varied chiefly with the nature of volcanic impact. Extraordinary suspended-sediment delivery has been greater and more persistent from zones of channel disturbance than from zones of hillslope disturbance. A classical observation in many "undisturbed" watersheds that

  10. iMUSH-aided fault-plane studies at Mount St. Helens, Washington: Evidence for magma recharge

    NASA Astrophysics Data System (ADS)

    Moran, S. C.; Abers, G. A.; Creager, K. C.; Denlinger, R. P.; Ulberg, C. W.; Vidale, J. E.

    2014-12-01

    Background seismicity has been relatively low at Mount St. Helens (MSH) following its last eruption in 2004-2008, with an average of 95 located M > 0 events per year. This is in marked contrast to the five years immediately following the 1980-86 eruptive period, when the yearly average rate was about 400 events. During that time there was clear evidence, in the form of rotated fault-plane solutions (FPS), that magma recharge was occurring at depths > 2 km. Despite lower seismicity rates and generally smaller earthquakes, an improved seismic network recorded data sufficient to allow for computation of 88 FPS for the period 2008-2013. These FPS show that stress fields at depths > 2 km were rotated in a manner similar to that seen post-1980-86, providing evidence that magma recharge is again occurring at MSH. A subtle trend towards slightly deeper earthquakes since 2011 is consistent with this hypothesis, as is previously reported outward motion on GPS stations that has been modeled with an inflationary source beneath the volcano at ~8-9 km depth. In the summer of 2014, 70 broadband seismometers were installed within 50 km of MSH as part of the iMUSH experiment, greatly increasing the number of stations close enough to MSH to obtain good recordings of MSH-generated events. By the Fall AGU meeting we expect to have several months of data collected and processed from iMUSH stations. These data should greatly improve constraints on first-motion FPS and/or the number of events for which well-constrained FPS can be computed. In addition, the density of three-component stations may allow for computation of moment tensor solutions for larger events (M > 1), which typically occur ~20 times per year. This would allow us to assess whether recent MSH events have significant non-double-couple components, something that could indicate fluid involvement and that has previously only been seen during eruptive periods at MSH via short-term deployments of broadband stations.

  11. Overview of the 2004 to 2006, and continuing, eruption of Mount St. Helens, Washington: Chapter 1 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

    USGS Publications Warehouse

    Scott, William E.; Sherrod, David R.; Gardner, Cynthia A.; Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

    2008-01-01

    Rapid onset of unrest at Mount St. Helens on September 23, 2004, initiated an uninterrupted lava-dome-building eruption that continues to the time of writing this overview (spring 2006) for a volume of papers focused on this eruption. About three weeks of intense seismic unrest and localized surface uplift, punctuated by four brief explosions, constituted a ventclearing phase, during which there was a frenzy of media attention and considerable uncertainty regarding the likely course of the eruption. The third week exhibited lessened seismicity and only minor venting of steam and ash, but rapid growth of the uplift, or welt, south of the 1980-86 lava dome proceeded as magma continued to push upward. Crystalrich dacite (~65 weight percent SiO2) lava first appeared at the surface on October 11, 2004, beginning the growth of a complex lava dome of uniform chemical composition accompanied by persistent but low levels of seismicity, rare explosions, low gas emissions, and frequent rockfalls. Petrologic studies suggest that the dome lava is chiefly of 1980s vintage, but with an admixed portion of new dacite. Alternatively, it may derive from a part of the magma chamber not tapped by 1980s eruptions. Regardless, detailed investigations of crystal chemistry, melt inclusions, and isotopes reveal a complex magmatic history. Largely episodic extrusion between 1980 and 1986 produced a relatively symmetrical lava dome composed of stubby lobes. In contrast, continuous extrusion at mean rates of about 5 m3/s in autumn 2004 to 3/s in early 2006 has produced an east-west ridge of three mounds with total volume about equal to that of the old dome. During much of late 2004 to summer 2005, a succession of spines, two recumbent and one steeply sloping and each mantled by striated gouge, grew to nearly 500 m in length in the southeastern sector of the 1980 crater and later disintegrated into two mounds. Since then, growth has been concentrated in the southwestern sector, producing a

  12. Evolving magma storage conditions beneath Mount St. Helens inferred from chemical variations in melt inclusions from the 1980-1986 and current (2004-2006) eruptions: Chapter 33 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

    USGS Publications Warehouse

    Blundy, Jon; Cashman, Katharine V.; Berlo, Kim; Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

    2008-01-01

    O contents, consistent with magma extraction from shallow depths. Highly enriched Li in melt inclusions suggests that vapor transport of Li is a characteristic feature of Mount St. Helens. Melt inclusions from the current eruption have subtly different trace-element chemistry from all but one of the 1980-86 melt inclusions, with steeper rareearth-element (REE) patterns and low U, Th, and high-fieldstrength elements (HFSE), indicating addition of a new melt component to the magma system. It is anticipated that increasing involvement of the new melt component will be evident as the current eruption proceeds.

  13. Archive of Digital Boomer Seismic Reflection Data Collected During USGS Field Activity 08LCA04 in Lakes Cherry, Helen, Hiawassee, Louisa, and Prevatt, Central Florida, September 2008

    USGS Publications Warehouse

    Harrison, Arnell S.; Dadisman, Shawn V.; Davis, Jeffrey B.; Flocks, James G.; Wiese, Dana S.

    2009-01-01

    From September 2 through 4, 2008, the U.S. Geological Survey and St. Johns River Water Management District (SJRWMD) conducted geophysical surveys in Lakes Cherry, Helen, Hiawassee, Louisa, and Prevatt, central Florida. This report serves as an archive of unprocessed digital boomer seismic reflection data, trackline maps, navigation files, GIS information, FACS logs, and formal FGDC metadata. Filtered and gained digital images of the seismic profiles are also provided. The archived trace data are in standard Society of Exploration Geophysicists (SEG) SEG-Y format (Barry and others, 1975) and may be downloaded and processed with commercial or public domain software such as Seismic Unix (SU). Example SU processing scripts and USGS software for viewing the SEG-Y files (Zihlman, 1992) are also provided.

  14. Post-Eruption Changes in Channel Geometry of Streams in the Toutle River Drainage Basin, 1980-82, Mount St. Helens, Washington

    USGS Publications Warehouse

    Meyer, D.F.; Nolan, K. Michael; Dodge, J.E.

    1985-01-01

    The May 18, 1980, eruption of Mount St. Helens, Washington, generated a debris avalanche, lateral blast, lahars, and tephra deposits that altered mainstem and tributary channels within the Toutle River drainage basin. Channel cross sections were monumented and surveyed on North Fork Toutle River and its tributaries, on South Fork Toutle River, on Green River, and on Toutle River in 1980 and 1981. These streams drain the north and west flanks of the volcano. The network of channel cross sections was surveyed more frequently following periods of higher flow. The repetitive cross-section surveys provide measurements of bank erosion or accretion and of channel erosion or aggradation. These data can be used to determine erosion rates, and to identify sources and storage sites of sediment in sediment budget computations. This report presents channel cross-section profiles constructed from the survey data collected during water years 1980 through 1982.

  15. Hydrologic data for computation of sediment discharge : Toutle and North Fork Toutle Rivers near Mount St. Helens, Washington, water years 1980-84

    USGS Publications Warehouse

    Childers, Dallas; Hammond, Stephen E.; Johnson, William P.

    1988-01-01

    Immediately after the devastating May 18, 1980, eruption of Mount St. Helens, a program was initiated by the U.S. Geological Survey to study the streamflow and sediment characteristics of streams impacted by the eruption. Some of the data gathered in that program are presented in this report. Data are presented for two key sites in the Toutle River basin: North Fork Toutle River near Kid Valley, and Toutle River at Tower Road, near Silver Lake. The types of data presented are appropriate for use with sediment transport formulas; however, the data are also intended for use in a wide variety of additional applications. The data presented in this report are unique because they delineate flow conditions possessing great potential fo sediment transport. The data define unusually high suspended-sediment concentration. Data defining hydraulic, peak discharge, suspended-sediment, and bed-material characteristics are presented. (USGS)

  16. Preliminary report on physical, chemical and mineralogical composition and health implications of ash from the Mount St. Helens eruption of May 18, 1980

    SciTech Connect

    Not Available

    1980-06-01

    On May 18, 1980 at 8:32 AM Pacific Daylight Time, a major eruption of ash and pyroclastics occurred from the Mount St. Helens volcano in Washington State. These and subsequent eruptions resulted in deposition of volcanic ash on large areas of the state of Washington and neighboring states. Beginning the day of the eruption and continuing through the following week, samples of the ash were collected for analysis by Battelle staff from various parts of eastern Washington and Montana. Specifically, samples were obtained from Richland, Yakima, Ahtanum, Tieton Ranger Station, Pullman, Rosalia, Moses Lake, Spokane, Ellensburg, Washington and Missoula, Montana. These materials were subjected to a variety of analyses including chemical, mineralogical and physical characterization and an in vitro biological assay to determine the effects of the ash on the pulmonary macrophage. This test gives an indication of the potential of the ash to cause respiratory diseases such as silicosis. Preliminary results of these various analyses are described.

  17. Analysis of long-period seismic waves excited by the May 18, 1980, eruption of Mount St. Helens - A terrestrial monopole

    NASA Technical Reports Server (NTRS)

    Kanamori, H.; Given, J. W.

    1982-01-01

    The eruption of Mount St. Helens on May 18, 1980, excited long-period seismic waves, and high-quality digital seismograms were recorded. The present investigation is concerned with the results of detailed analyses of Rayleigh and Love waves excited by this eruption. Since the elastic response of the earth is very accurately known, it is possible to retrieve the source parameters of this unique event from observations at far-field. It is shown that the source can be represented by a nearly horizontal single force. The conducted analysis is concerned with only long-period characteristics of the source. The short-period behavior of the source is difficult to determine from surface waves because the available knowledge of the earth's response is less accurate than at long periods.

  18. Changes in channel geometry of six eruption-affected tributaries of the Lewis River, 1980-82, Mount St. Helens, Washington

    USGS Publications Warehouse

    Martinson, H.A.; Finneran, S.D.; Topinka, L.J.

    1984-01-01

    The May 18, 1980, eruption of Mount St. Helens generated a lateral blast, lahars and tephra deposits that altered tributary channels in the Lewis River drainage basin. In order to assess potential flood hazards, study channel adjustments, and construct a sediment budget for the perturbed drainages on the east and southeast flanks of the volcano, channel cross sections were monumented and surveyed on Pine Creek, Muddy River, and Smith Creek during September and October of 1980. Additional cross sections were monumented and surveyed on Swift Creek, Bean Creek, and Clearwater Creek during the summer of 1981. The network of 88 channel cross sections has been resurveyed annually. Selected cross sections have been surveyed more frequently, following periods of higher flow. The repetitive cross-section surveys provide measurements of bank erosion or accretion and of channel erosion or aggradation. The report presents channel cross-section profiles constructed from the survey data collected during water years 1980-82. (USGS)

  19. The effects of ground water, slope stability, and seismic hazards on the stability of the South Fork Castle Creek blockage in the Mount St. Helens area, Washington

    USGS Publications Warehouse

    Meyer, William; Sabol, M.A.; Glicken, H.X.; Voight, Barry

    1985-01-01

    A slope stability analysis on the South Fork Castle Creek debris avalanche blockage, near Mount St. Helens, Washington, was conducted to determine the likelihood of mass failure of the blockage and resultant breakout of South Fork Castle Creek Lake. On the basis of material properties, groundwater levels, and seismic history of the blockage, slope stability with and without earthquake-induced forces was determined. Results indicated that the blockage will not fail from gravitational forces at September 1983 groundwater levels. An increase of 25 feet or more in water levels could cause local failures, but massive failure of the blockage is improbable. Blockage slopes are potentially unstable for present and higher water levels if an earthquake with magnitude greater than 6.0 should occur. Retrogressive slope failures are possible, but lowering of the blockage crest below lake level and consequent lake breakout are considered remote. Significant earthquake shaking could cause cracks in the blockage that might facilitate piping. (USGS)

  20. Ground Deformation Associated with the 2004-2005 Dome-building Eruption of Mount St. Helens, Washington

    NASA Astrophysics Data System (ADS)

    Dzurisin, D.; Lisowski, M.; Schilling, S. P.; Lahusen, R. G.; Sherrod, D. R.; Iwatsubo, E. Y.; Diefenbach, A.; Thompson, S. K.

    2005-12-01

    Following nearly 18 years of eruptive quiescence, a new dacite lava dome began growing in the crater at Mount St. Helens in October 2004. Extrusion was preceded by an intense swarm of shallow earthquakes starting on September 23, by several small explosions starting on October 1, and by remarkable uplift of the south crater floor and glacier. The resulting welt, which was first identified in air photos on September 27, was 450 m wide and 100 m high on October 11 when the first new lava emerged from it. Campaign-style GPS surveys in 2000 and 2003 of a 50-station network concentrated within 10 km of the volcano's summit, but extending more than 30 km radially and covering an area of more than 7400 km2, revealed no surface deformation indicative of magmatic inflation or deflation. A single-frequency continuous GPS station on the 1980-1986 lava dome and annual GPS surveys of points on the dome and surrounding crater floor showed only subsidence of the dome at rates of a few cm/yr, which we attribute to cooling and compaction. A continuous GPS station (JRO1) located 9 km NNW of the vent abruptly started moving toward the volcano, suggesting deflation of a deep magma reservoir, concurrent with the onset of seismicity. Southward motion of JRO1, which is distinctly different from the regional trend of clockwise block rotation in SW Washington, gradually slowed from ~0.5 mm/d before emergence of the new dome to an average of ~0.04 mm/d during the first 11 months of continuous extrusion. Meanwhile, the extrusion rate was relatively steady at ~2 m3/s. Taken together, the JRO1 GPS and extrusion-rate results indicate that the crustal magma reservoir feeding the eruption is being replenished. Twelve new continuous GPS stations were installed on or near the volcano starting in October 2004 by the USGS Cascades Volcano Observatory and UNAVCO Inc., the latter representing the Plate Boundary Observatory. Like JRO1, these stations moved mostly toward the volcano during the ensuing 11

  1. Analysis of recently digitized continuous seismic data recorded during the March-May, 1980, eruption sequence at Mount St. Helens

    NASA Astrophysics Data System (ADS)

    Moran, S. C.; Malone, S. D.

    2013-12-01

    The May 18, 1980, eruption of Mount St. Helens (MSH) was an historic event, both for society and for the field of volcanology. However, our knowledge of the eruption and the precursory period leading up it is limited by the fact that most of the data, particularly seismic recordings, were not kept due to severe limitations in the amount of digital data that could be handled and stored using 1980 computer technology. Because of these limitations, only about 900 digital event files have been available for seismic studies of the March-May seismic sequence out of a total of more than 4,000 events that were counted using paper records. Fortunately, data from a subset of stations were also recorded continuously on a series of 24 analog 14-track IRIG magnetic tapes. We have recently digitized these tapes and time-corrected and cataloged the resultant digital data streams, enabling more in-depth studies of the (almost) complete pre-eruption seismic sequence using modern digital processing techniques. Of the fifteen seismic stations operating near MSH for at least a part of the two months between March 20 and May 18, six stations have relatively complete analog recordings. These recordings have gaps of minutes to days because of radio noise, poor tape quality, or missing tapes. In addition, several other stations have partial records. All stations had short-period vertical-component sensors with very limited dynamic range and unknown response details. Nevertheless, because the stations were at a range of distances and were operated at a range of gains, a variety of earthquake sizes were recorded on scale by at least one station, and therefore a much more complete understanding of the evolution of event types, sizes and character should be achievable. In our preliminary analysis of this dataset we have found over 10,000 individual events as recorded on stations 35-40 km from MSH, spanning a recalculated coda-duration magnitude range of ~1.5 to 4.1, including many M < 3

  2. Fragmentation and Cataclasis of Lava Domes: Field Evidence of Conduit-Margin Faulting and Cryptodome Unloading at Mount St. Helens

    NASA Astrophysics Data System (ADS)

    Pallister, J. S.; Hagstrum, J.; Cashman, K.; Tuffen, H.

    2007-12-01

    Structures and textures preserved in dome rocks reveal much about ascent history, seismicity, and dynamics of eruptions. The current eruption of Mount St. Helens (MSH) produced dacite spines mantled by fault gouge and breccia. Flow-banded spine interiors attest to early degassing and ductile deformation; micro-textures and structures in the spine margins indicate entirely brittle shear, rock breakage, grain-flow and gas-escape along fractures. Paleomagnetic pole positions and demagnetization data constrain cataclasis to the sub-vertical volcanic conduit at temperatures above 500°-570°C. Low water content of matrix glass and presence of tridymite require nearly complete decompression-driven solidification at depths <1 km, coincident with the eruption's seismogenic zone. 1-3 m thick cataclastic breccia of spine margins contains multiple Reidel shears in a conjugate set formed by shear between the vertically extruding spines and conduit walls. This breccia is overlain by a thin (<10 cm) outer mantle of finely comminuted gouge with 1-3 mm-thick, surface-parallel layers of slickenside-bearing ultracataclasite, forming through-going fault planes. Slickenside lineations and direction indicators are consistent with upward transport of the spines. These relations document two dominant modes of brittle failure in the spine margins, similar to the brittle S-C fabrics seen in tectonic fault zones. The Reidel shears represent limited-slip planes (S-shears), which are inclined relative to the primary bounding fault planes (C-surfaces). We infer that the Reidel shears formed as multiple, domino-like episodes of fracture, prior to transfer of slip to the bounding C-surfaces. Because the depth of deformation is the same as the depth of the seismogenic zone, and because there are two distinct modes of brittle fracture (S and C fabrics) as well as two distinct types of earthquakes (volcano-tectonic and longer-period hybrids) it is logical to infer that these structures are sources

  3. Rock property measurements guide interpretation of electromagnetic, magnetic and gravity models at Mts. Adams, Baker, Rainier and St. Helens (Invited)

    NASA Astrophysics Data System (ADS)

    Finn, C.; Bedrosian, P. A.; Horton, R.; Polster, S.

    2010-12-01

    Mt. Adams north of the summit. Alteration at Mt. Baker is restricted to thinner (<300 m) zones beneath Sherman Crater and the Dorr Fumerole Fields. The presence of water not only helps form clay minerals that weaken the edifice but also can reduce the pore pressures, increasing the potential for slope failure. In addition, water with entrained melting ice acts as a lubricant to transform debris avalanches into lahars. The EM data identified water-saturated rocks from the surface to the detection limit (100 - 200 m) in discreet zones at Mt. Rainier and Mt Adams and over the entire summit region at Mt. Baker. At Mt. St. Helens, perched aquifers are identified in the 1980 avalanche deposits as well as in older, thick breccia or avalanche deposits. The modeled distribution of alteration and pore fluids helps identify likely sources for future alteration-related debris flows and clearly shows that debris flow hazard studies on altered volcanoes are greatly enhanced by magnetic, EM and gravity data.

  4. Dissociation of the Reach and the Grasp in the destriate (V1) monkey Helen: a new anatomy for the dual visuomotor channel theory of reaching.

    PubMed

    Whishaw, Ian Q; Karl, Jenni M; Humphrey, Nicholas K

    2016-08-01

    Dual visuomotor channel theory proposes that reaching depends on two neural pathways that extend from visual cortex (V1) to motor cortex via the parietal lobe. The Reach pathway directs the hand to the target's location and the Grasp pathway shapes the hand and digits for purchase. Sighted human participants integrate the Reach and the Grasp, but without vision they dissociate the movements to capitalize on tactile cues. They use a Reach with a relatively open hand to locate the target and then they use touch cues to shape the fingers to Grasp. After a V1 lesion, the rhesus monkey, Helen, learned to make near-normal visual discriminations based on size and brightness but displayed visual agnosia. She also learned to reach for food with her mouth and her hands. The present analysis of film of her reaching behavior shows that she dissociated the Reach and the Grasp, as do unsighted human participants reaching for a food target at a fixed location. Her rapid and direct Reach was made with an open hand and extended fingers to contact the food with the palm whereas her Grasp was initiated after she touched the food. She also visually fixated the target during the Reach and visually disengaged after target contact, as do sighted human participants. In contrast, Helen did integrate the Reach and the Grasp to take food from her mouth, demonstrating that she could integrate the movements using online tactile cues. The finding that extrastriate pathways can direct the hand toward extrinsic target properties (location) but not intrinsic target properties (size and shape) is discussed as a novel addition to dual visuomotor channel theory. PMID:27056084

  5. 238U sbnd 230Th sbnd 226Ra disequilibria in young Mount St. Helens rocks: time constraint for magma formation and crystallization

    NASA Astrophysics Data System (ADS)

    Volpe, Alan M.; Hammond, Paul E.

    1991-12-01

    We use 238U-series nuclides and 230Th/ 232Th ratios measured by mass spectrometry to constrain processes and time scales of calc-alkaline magma genesis at Mount St. Helens, Washington. Olivine basalt, pyroxene andesites and dacites that erupted 10-2 ka ago show 3-14% ( 230Th) sbnd ( 238U) and 6-54% 226Ra sbnd 230Th disequilibria. Mineral phases exhibit robust ( 226Ra) sbnd ( 230Th) fractionation. Plagioclase has large 65-280% ( 226Ra) excesses, and magnetite has large 65% ( 226Ra) deficits relative to ( 230Th). Calculated partition coefficients for Ba, Th, and U in mineral-groundmass pairs, except Ba in plagioclase, are low (⩽ 0.04). Correlation between ( 226Ra/ 230Th ) activity ratios and rm/BaTh element ratios in the minerals suggests that 226Ra partitions similar to Ba during crystallization. Internal ( 230Th) sbnd ( 238U) isochrons for 1982 summit and East Dome dacites and Goat Rocks and Kalama andesites show that closed Th sbnd U system fractionation occurred 2-6 ka ago. Apparent internal isochrons for Castle Creek basalt (34 ka) and andesite (27 ka) suggest longer magma chamber residence times and mixing of old crystals and young melt. Mineral ( 226Ra) sbnd ( 230Th) disequilibrium on Ba-normalized internal isochron diagrams suggests average magma chamber residence times of 500-3000 years. In addition, radioactive ( 226Ra/ 230Th ) heterogeneity between minerals and groundmass or whole rock is evidence for open-system Ra sbnd Th behavior. This heterogeneity suggests there has been recent, post-crystallization, changes in melt chemical composition that affected 226Ra more than 230Th. Clearly, magma fractionation, residence and transport of crystal-melt before eruption of chemically diverse lavas at Mount St. Helens occurs over geologically short periods.

  6. Patterns of earthquakes and the effect of solid earth and ocean load tides at Mount St. Helens prior to the May 18, 1980, eruption

    SciTech Connect

    McNutt, S.R.; Beavan, R.J.

    1984-05-10

    Seismographs near Mount St. Helens Volcano recorded an earthquake swarm lasting nearly 2 months prior to the May 18, 1980, eruption. The earthquakes are divided into four classes based on station CPW (..delta.. = 116 km) seismogram characteristics: (1) events with Sv:P amplitude ratio > 3 and dominant frequency > 3 Hz; (2) events with Sv:P ratio between 1 and 3 and dominant frequency > 2 Hz; (3) events similar to characteristic 2 but with a strong (probably surface wave) phase just after the S phase; and (4) events with frequencies between 1 and 2 Hz lacking a clear S phase. The seismicity pattern for each of the four classes is unique. Solid earth stress and strain tides were calculated at the average hypocentral depth of 4 km. Stress and strain tides induced by ocean loading were also calculated; their amplitudes are typically 20-40% those of the solid earth tides at the location of Mount St. Helens. A weak but significant correlation exists between the latter two classes of events and the tides for a time interval of about 5 days preceding the first onset of volcanic tremor and about 5 days thereafter. The polarity of the correlation is opposite for the two classes of events. In each case, the phase of the correlation changes systematically with time, the changes coinciding with the onset of tremor on March 31 and with a pronounced decrease in earthquake energy release rate on April 3. There are no significant correlations between the tides and the number of events or energy release of these two classes of earthquakes during any other interval between March 20 and May 18, 1980. The first two classes of events show no evidence of significant tidal correlation at any time during the study period. 20 references, 8 figures, 2 tables.

  7. Frictional properties of gouge generated during the 2004-2005 lava dome extrusion at Mount St. Helens and implications for seismicity

    NASA Astrophysics Data System (ADS)

    Moore, P. L.; Iverson, N. R.; Iverson, R. M.

    2005-12-01

    Lava dome extrusion during the 2004-2005 eruption of Mount St. Helens has been accompanied by abundant, nearly periodic, shallow-focus seismicity. This seismic activity is hypothesized to result from incremental uplift of a nearly crystalline magma plug driven by magma ascent from below. Wear along the margin of the uplifting plug has formed a layer of striated, crushed rock, or gouge, which accommodates the relative displacement. Interpretation of the seismicity therefore requires some knowledge of the frictional properties of this gouge. Laboratory experiments were performed in a large ring-shear device to test the dependence of the gouge's peak and steady-state frictional strength on shearing rate and hold time. The sample (0.012 m3 in volume) was sheared under constant normal stresses ranging from 4 kPa to nearly 0.2 MPa and at rates ranging from 10-6 to 10-3 m s-1. At all normal stresses, the gouge exhibited rate-weakening behavior when sheared at rates slower than 10-4 m s-1, but at faster rates there was a transition to rate-strengthening. In a series of slide-hold-slide tests (hold time ranging from 3 to almost 105 seconds) performed under constant normal stress and shearing rate, the peak strength of the gouge was found to increase logarithmically with hold time. These results have several implications for the ongoing seismicity at Mount St. Helens. The rate-weakening behavior at low slip rates indicates that the gouge is susceptible to stick-slip behavior and thus may account for observed seismicity. Indeed, regular stick-slip oscillations were observed in two experiments under the highest load and lowest rates of shear. However, because there is a transition to rate-strengthening at higher slip rates, the gouge properties may impose a limit on the size of seismogenic slip events. Additionally, the dependence of peak strength on hold time suggests that slip history may also influence the magnitudes of seismic events.

  8. A Record of Magmatic Water Content Preserved in Hydroxyl Concentrations of Plagioclase Phenocrysts From the 1980-1981 Eruption Sequence of Mount St. Helens

    NASA Astrophysics Data System (ADS)

    Johnson, E. A.

    2004-12-01

    Volatiles, and particularly water, influence many of the properties of volcanic systems including melt viscosity and crystallinity, and the explosive or effusive nature of an eruption. Magmatic water content could potentially be determined by measurement of OH concentrations in phenocrysts, assuming an equilibrium partitioning of water between the phenocrysts and melt. The concentration of OH in volcanic feldspars may also reflect many factors other than magmatic water content, including melt composition, oxygen fugacity, and thermal history. In this study, the OH concentrations of plagioclase phenocryts from four eruptions of Mount St. Helens between May 18, 1980 and April 1981 were measured using infrared spectroscopy in order to evaluate this method of determining magmatic water content. The eruption temperature, oxygen fugacity, and bulk chemical composition were all fairly constant through the eruption sequence from 1980-1981 at Mount St. Helens. The water content of melts from successive eruptions decreased from 4.6 wt% H2O for the Plinian eruption on May 18, 1980 (Rutherford et al. 1985, JGR 90, 2929-2947), to less than 1 wt% H2O for the latest dome-forming dacites. Plagioclase from the pumice erupted during the May 18, 1980 event contains 200 ppm H2O by weight as structural hydroxyl groups, whereas feldspars from subsequent explosive eruptions with melt water concentrations about half that of the May 18 eruption (Melson 1983, Science 221, 1387-1391) contain about half the structural OH content (about 110 ppm for the October 16, 1980 and August 7, 1980 eruptions). The effusive dome-building eruption of April 1981 contains plagioclase with very low (about 20 ppm) water content, implying possible diffusive loss of hydrogen during the prolonged period of eruption. Homogeneous distribution of OH in feldspar grains > 100 micrometers is observed even for those grains with pronounced major element zoning. These data show that, in the absence of changes in oxygen

  9. Imaging Magma Under St. Helens (iMUSH): Details of passive-source seismic deployment and preliminary 3-D velocity structure

    NASA Astrophysics Data System (ADS)

    Ulberg, C. W.; Creager, K. C.; Moran, S. C.; Abers, G. A.; Denlinger, R. P.; Hotovec-Ellis, A. J.; Vidale, J. E.; Kiser, E.; Levander, A.; Schultz, A.

    2014-12-01

    The imaging Magma Under St. Helens (iMUSH) experiment aims to delineate the extent of the magmatic system beneath Mount St. Helens (MSH) in Washington State. The experiment involves active- and passive-source seismology, magnetotellurics, and geochemistry/petrology. Seventy passive-source broadband seismometers were deployed in a 100-km-diameter array centered on MSH, with an average spacing of 10 km, and a planned duration of two years. The deployment over two weeks in June 2014 involved a group of 18 people split into 6 teams. Approximately half of the seismic stations have aircell batteries and/or pole-mounted solar panels in order to maintain power through deep snow at higher elevations during the winter months. Data will be retrieved 2-4 times a year throughout the duration of the experiment. The first service run performed in mid-July 2014 had a 98.4% data recovery. This is one of the largest wide-aperture two-dimensional arrays covering a volcano anywhere. The active-source portion of the experiment successfully set off 23 shots in late-July 2014. These were recorded clearly at permanent stations run by the Pacific Northwest Seismic Network up to 200 km away, and are expected to be well-recorded on many of the 70 broadband seismometers in addition to the 2500 Reftek "Texans" deployed temporarily for this purpose. For the 2-4 weeks of broadband data collected in July, local earthquakes down to magnitude 0 are recorded across the array, with clear P- and S- arrivals. Earthquakes of this size occur daily within 50 km of MSH. We are keeping a careful catalog of all activity in the region for the duration of the iMUSH experiment. We will pick P- and S-wave travel times at the 70 broadband stations from local earthquakes and active shots, for available data from between June and October 2014. We will also use a tomographic code (Preston et al, 2003, Science) to invert the travel times to obtain preliminary earthquake location and 3-D velocity structure.

  10. High-resolution digital elevation model of Mount St. Helens crater and upper North Fork Toutle River basin, Washington, based on an airborne lidar survey of September 2009

    USGS Publications Warehouse

    Mosbrucker, Adam

    2014-01-01

    The lateral blast, debris avalanche, and lahars of the May 18th, 1980, eruption of Mount St. Helens, Washington, dramatically altered the surrounding landscape. Lava domes were extruded during the subsequent eruptive periods of 1980–1986 and 2004–2008. More than three decades after the emplacement of the 1980 debris avalanche, high sediment production persists in the North Fork Toutle River basin, which drains the northern flank of the volcano. Because this sediment increases the risk of flooding to downstream communities on the Toutle and Cowlitz Rivers, the U.S. Army Corps of Engineers (USACE), under the direction of Congress to maintain an authorized level of flood protection, built a sediment retention structure on the North Fork Toutle River in 1989 to help reduce this risk and to prevent sediment from clogging the shipping channel of the Columbia River. From September 16–20, 2009, Watershed Sciences, Inc., under contract to USACE, collected high-precision airborne lidar (light detection and ranging) data that cover 214 square kilometers (83 square miles) of Mount St. Helens and the upper North Fork Toutle River basin from the sediment retention structure to the volcano's crater. These data provide a digital dataset of the ground surface, including beneath forest cover. Such remotely sensed data can be used to develop sediment budgets and models of sediment erosion, transport, and deposition. The U.S. Geological Survey (USGS) used these lidar data to develop digital elevation models (DEMs) of the study area. DEMs are fundamental to monitoring natural hazards and studying volcanic landforms, fluvial and glacial geomorphology, and surface geology. Watershed Sciences, Inc., provided files in the LASer (LAS) format containing laser returns that had been filtered, classified, and georeferenced. The USGS produced a hydro-flattened DEM from ground-classified points at Castle, Coldwater, and Spirit Lakes. Final results averaged about five laser last

  11. An updated numerical simulation of the ground-water flow system for the Castle Lake debris dam, Mount St. Helens, Washington, and implications for dam stability against heave

    USGS Publications Warehouse

    Roeloffs, Evelyn A.

    1994-01-01

    A numerical simulation of the ground-water flow system in the Castle Lake debris dam, calibrated to data from the 1991 and 1992 water years, was used to estimate factors of safety against heave and internal erosion. The Castle Lake debris dam, 5 miles northwest of the summit of Mount St. Helens, impounds 19,000 acre-ft of water that could pose a flood hazard in the event of a lake breakout. A new topographic map of the Castle Lake area prior to the 1980 eruption of Mount St. Helens was prepared and used to calculate the thickness of the debris avalanche deposits that compose the dam. Water levels in 22 piezometers and discharges from seeps on the dam face measured several times per year beginning in 1990 supplemented measurements in 11 piezometers and less frequent seep discharge measurements made since 1983. Observations in one group of piezometers reveal heads above the land surface and head gradients favoring upward flow that correspond to factors of safety only slightly greater than 2. The steady-state ground-water flow system in the debris dam was simulated using a threedimensional finite difference computer program. A uniform, isotropic model having the same shape as the dam and a hydraulic conductivity of 1.55 ft/day simulates the correct water level at half the observation points, but is in error by 10 ft or more at other points. Spatial variations of hydraulic conductivity were required to calibrate the model. The model analysis suggests that ground water flows in both directions between the debris dam and Castle Lake. Factors of safety against heave and internal erosion were calculated where the model simulated upward flow of ground water. A critical gradient analysis yields factors of safety as low as 2 near the piezometers where water level observations indicate low factors of safety. Low safety factors are also computed near Castle Creek where slumping was caused by a storm in January, 1990. If hydraulic property contrasts are present in areas of the

  12. Tracing pre-eruptive magma degassing using ( 210Pb/ 226Ra) disequilibria in the volcanic deposits of the 1980-1986 eruption of Mount St. Helens

    NASA Astrophysics Data System (ADS)

    Berlo, Kim; Turner, Simon; Blundy, Jon; Black, Stuart; Hawkesworth, Chris

    2006-09-01

    Disequilibria between 210Pb and 226Ra can be used to trace magma degassing, because the intermediate nuclides, particularly 222Rn, are volatile. Products of the 1980-1986 eruptions of Mount St. Helens have been analysed for ( 210Pb/ 226Ra). Both excesses and deficits of 210Pb are encountered suggesting rapid gas transfer. The time scale of diffuse, non-eruptive gas escape prior to 1980 as documented by 210Pb deficits is on the order of a decade using the model developed by Gauthier and Condomines (Earth Planet. Sci. Lett. 172 (1999) 111-126) for a non-renewed magma chamber and efficient Rn removal. The time required to build-up 210Pb excess is much shorter (months) as can be observed from steady increases of ( 210Pb/ 226Ra) with time during 1980-1982. The formation of 210Pb excess requires both rapid gas transport through the magma and periodic blocking of gas escape routes. Superposed on this time trend is the natural variability of ( 210Pb/ 226Ra) in a single eruption caused by tapping magma from various depths. The two time scales of gas transport, to create both 210Pb deficits and 210Pb excesses, cannot be reconciled in a single event. Rather 210Pb deficits are associated with pre-eruptive diffuse degassing, while 210Pb excesses document the more vigorous degassing associated with eruption and recharge of the system.

  13. Self-similar rupture implied by scaling properties of volcanic earthquakes occurring during the 2004-2008 eruption of Mount St. Helens, Washington

    USGS Publications Warehouse

    Harrington, Rebecca M.; Kwiatek, Grzegorz; Moran, Seth C.

    2015-01-01

    We analyze a group of 6073 low-frequency earthquakes recorded during a week-long temporary deployment of broadband seismometers at distances of less than 3 km from the crater at Mount St. Helens in September of 2006. We estimate the seismic moment (M0) and spectral corner frequency (f0) using a spectral ratio approach for events with a high signal-to-noise (SNR) ratio that have a cross-correlation coefficient of 0.8 or greater with at least five other events. A cluster analysis of cross-correlation values indicates that the group of 421 events meeting the SNR and cross-correlation criteria forms eight event families that exhibit largely self-similar scaling. We estimate the M0 and f0 values of the 421 events and calculate their static stress drop and scaled energy (ER/M0) values. The estimated values suggest self-similar scaling within families, as well as between five of eight families (i.e.,  and  constant). We speculate that differences in scaled energy values for the two families with variable scaling may result from a lack of resolution in the velocity model. The observation of self-similar scaling is the first of its kind for such a large group of low-frequency volcanic tectonic events occurring during a single active dome extrusion eruption.

  14. Changes in seismic velocity during the first 14 months of the 2004–2008 eruption of Mount St. Helens, Washington

    USGS Publications Warehouse

    Hotovec-Ellis, A.J.; Vidale, J.E.; Gomberg, Joan S.; Thelen, Weston A.; Moran, Seth C.

    2015-01-01

    Mount St. Helens began erupting in late 2004 following an 18 year quiescence. Swarms of repeating earthquakes accompanied the extrusion of a mostly solid dacite dome over the next 4 years. In some cases the waveforms from these earthquakes evolved slowly, likely reflecting changes in the properties of the volcano that affect seismic wave propagation. We use coda-wave interferometry to quantify small changes in seismic velocity structure (usually <1%) between two similar earthquakes and employed waveforms from several hundred families of repeating earthquakes together to create a continuous function of velocity change observed at permanent stations operated within 20 km of the volcano. The high rate of earthquakes allowed tracking of velocity changes on an hourly time scale. Changes in velocity were largest near the newly extruding dome and likely related to shallow deformation as magma first worked its way to the surface. We found strong correlation between velocity changes and the inverse of real-time seismic amplitude measurements during the first 3 weeks of activity, suggesting that fluctuations of pressure in the shallow subsurface may have driven both seismicity and velocity changes. Velocity changes during the remainder of the eruption likely result from a complex interplay of multiple effects and are not well explained by any single factor alone, highlighting the need for complementary geophysical data when interpreting velocity changes.

  15. Bayesian inversion of data from effusive volcanic eruptions using physics-based models: Application to Mount St. Helens 2004--2008

    USGS Publications Warehouse

    Anderson, Kyle; Segall, Paul

    2013-01-01

    Physics-based models of volcanic eruptions can directly link magmatic processes with diverse, time-varying geophysical observations, and when used in an inverse procedure make it possible to bring all available information to bear on estimating properties of the volcanic system. We develop a technique for inverting geodetic, extrusive flux, and other types of data using a physics-based model of an effusive silicic volcanic eruption to estimate the geometry, pressure, depth, and volatile content of a magma chamber, and properties of the conduit linking the chamber to the surface. A Bayesian inverse formulation makes it possible to easily incorporate independent information into the inversion, such as petrologic estimates of melt water content, and yields probabilistic estimates for model parameters and other properties of the volcano. Probability distributions are sampled using a Markov-Chain Monte Carlo algorithm. We apply the technique using GPS and extrusion data from the 2004–2008 eruption of Mount St. Helens. In contrast to more traditional inversions such as those involving geodetic data alone in combination with kinematic forward models, this technique is able to provide constraint on properties of the magma, including its volatile content, and on the absolute volume and pressure of the magma chamber. Results suggest a large chamber of >40 km3 with a centroid depth of 11–18 km and a dissolved water content at the top of the chamber of 2.6–4.9 wt%.

  16. Effects of the Mount St. Helens eruption on the benthic fauna of the Toutle River, Muddy River, and Pine Creek drainage basins, Washington

    USGS Publications Warehouse

    Fuste, Luis A.

    1981-01-01

    During several periods of volcanic-ash eruption at Mount St. Helens, Wash., (March 30, May 25-26, May 30-June 2, and June 12-13, 1980) strong winds from the north occurred at high altitudes. As a result, the volcanic ash fell some 50 miles to the south in the Bull Run watershed, the principal water-supply source for the metropolitan area of Portland, Oreg. Water samples collected from three stream sites within the watershed were compared with samples collected during the same season in previous years. No detectable changes were noted in chemical characteristics. Precipitation samples collected immediately after the June 12-13 ash fall ranged in specific conductance from 20 to 41 micromhos per centimeter at 25C and in pH from 4.0 to 4.3 pH units. Stream samples collected during the May-June period ranged in specific conductance from 18 to 28 micromhos per centimeter at 25C and in pH from 6.7 to 7.5 pH units. Volcanic-ash samples were collected and analyzed for particle size, chemical composition, and weight. Significant differences in particle size of ash were found in samples from two separate eruptions. (USGS)

  17. Correlations of turbidity to suspended-sediment concentration in the Toutle River Basin, near Mount St. Helens, Washington, 2010-11

    USGS Publications Warehouse

    Uhrich, Mark A.; Kolasinac, Jasna; Booth, Pamela L.; Fountain, Robert L.; Spicer, Kurt R.; Mosbrucker, Adam R.

    2014-01-01

    Researchers at the U.S. Geological Survey, Cascades Volcano Observatory, investigated alternative methods for the traditional sample-based sediment record procedure in determining suspended-sediment concentration (SSC) and discharge. One such sediment-surrogate technique was developed using turbidity and discharge to estimate SSC for two gaging stations in the Toutle River Basin near Mount St. Helens, Washington. To provide context for the study, methods for collecting sediment data and monitoring turbidity are discussed. Statistical methods used include the development of ordinary least squares regression models for each gaging station. Issues of time-related autocorrelation also are evaluated. Addition of lagged explanatory variables was used to account for autocorrelation in the turbidity, discharge, and SSC data. Final regression model equations and plots are presented for the two gaging stations. The regression models support near-real-time estimates of SSC and improved suspended-sediment discharge records by incorporating continuous instream turbidity. Future use of such models may potentially lower the costs of sediment monitoring by reducing time it takes to collect and process samples and to derive a sediment-discharge record.

  18. Source mechanisms of persistent shallow earthquakes during eruptive and non-eruptive periods between 1981 and 2011 at Mount St. Helens, Washington

    USGS Publications Warehouse

    Lehto, Heather L.; Roman, Diana C.; Moran, Seth C.

    2013-01-01

    Shallow seismicity between 0 and 3-km depth has persisted at Mount St. Helens, Washington (MSH) during both eruptive and non-eruptive periods for at least the past thirty years. In this study we investigate the source mechanisms of shallow volcano-tectonic (VT) earthquakes at MSH by calculating high-quality hypocenter locations and fault plane solutions (FPS) for all VT events recorded during two eruptive periods (1981–1986 and 2004–2008) and two non-eruptive periods (1987–2004 and 2008–2011). FPS show a mixture of normal, reverse, and strike-slip faulting during all periods, with a sharp increase in strike-slip faulting observed in 1987–1997 and an increase in normal faulting in 1998–2004. FPS P-axis orientations show a ~ 90° rotation with respect to regional σ1 (N23°E) during 1981–1986 and 2004–2008, bimodal orientations (~ N-S and ~ E-W) during 1987–2004, and bimodal orientations at ~ N-E and ~ S-W from 2008–2011. We interpret these orientations to likely be due to pressurization accompanying the shallow intrusion and subsequent eruption of magma as domes during 1981–1986 and 2004–2008 and the buildup of pore pressure beneath a seismogenic volume (located at 0–1 km) with a smaller component due to the buildup of tectonic forces during 1987–2004 and 2008–2011.

  19. Improved constraints on the estimated size and volatile content of the Mount St. Helens magma system from the 2004-2008 history of dome growth and deformation

    USGS Publications Warehouse

    Mastin, L.G.; Lisowski, M.; Roeloffs, E.; Beeler, N.

    2009-01-01

    The history of dome growth and geodetic deflation during the 2004-2008 Mount St. Helens eruption can be fit to theoretical curves with parameters such as reservoir volume, bubble content, initial overpressure, and magma rheology, here assumed to be Newtonian viscous, with or without a solid plug in the conduit center. Data from 2004-2008 are consistent with eruption from a 10-25 km3 reservoir containing 0.5-2% bubbles, an initial overpressure of 10-20 MPa, and no significant, sustained recharge. During the eruption we used curve fits to project the eruption's final duration and volume. Early projections predicted a final volume only about half of the actual value; but projections increased with each measurement, implying a temporal increase in reservoir volume or compressibility. A simple interpretation is that early effusion was driven by a 5-10 km3, integrated core of fluid magma. This core expanded with time through creep of semi-solid magma and host rock. Copyright 2009 by the American Geophysical Union.

  20. Improved constraints on the estimated size and volatile content of the Mount St. Helens magma system from the 2004-2008 history of dome growth and deformation

    USGS Publications Warehouse

    Mastin, Larry G.; Lisowski, Mike; Roeloffs, Evelyn; Beeler, Nick

    2009-01-01

    The history of dome growth and geodetic deflation during the 2004-2008 Mount St. Helens eruption can be fit to theoretical curves with parameters such as reservoir volume, bubble content, initial overpressure, and magma rheology, here assumed to be Newtonian viscous, with or without a solid plug in the conduit center. Data from 2004-2008 are consistent with eruption from a 10-25 km3 reservoir containing 0.5-2% bubbles, an initial overpressure of 10-20 MPa, and no significant, sustained recharge. During the eruption we used curve fits to project the eruption's final duration and volume. Early projections predicted a final volume only about half of the actual value; but projections increased with each measurement, implying a temporal increase in reservoir volume or compressibility. A simple interpretation is that early effusion was driven by a 5-10 km3, integrated core of fluid magma. This core expanded with time through creep of semi-solid magma and host rock.

  1. Channel geometry and hydrologic data for six eruption-affected tributaries of the Lewis River, Mount St. Helens, Washington, water years 1983-84

    USGS Publications Warehouse

    Martinson, H.A.; Hammond, H.E.; Mast, W.W.; Mango, P.D.

    1986-01-01

    The May 18, 1980, eruption of Mount St. Helens generated a lateral blast, lahars, and tephra deposits that altered stream channels in the Lewis River drainage basin. In order to assess potential flood hazards, monitor channel adjustments, and construct a sediment budget for disturbed drainages on the east and southeast flanks of the volcano, channel cross sections were monumented and surveyed on Pine Creek, Muddy River, and Smith Creek during September and October of 1980. Additional cross sections were monumented and surveyed on Swift Creek, Bean Creek , and Clearwater Creek during 1981. This network of channel cross sections has been resurveyed annually. Selected cross sections have been surveyed more frequently, following periods of higher flow. Longitudinal stream profiles of the low-water thalweg and (or) water surfaces were surveyed periodically for selected short reaches of channel. Corresponding map views for these reaches were constructed using the survey data and aerial photographs. This report presents plots of channel cross-section profiles, longitudinal stream profiles, and channel maps constructed from survey data collected during water years 1983-84. (USGS)

  2. Communicating Uncertainty to the Public During Volcanic Unrest and Eruption -A Case Study From the 2004-2005 Eruption of Mount St. Helens, USA

    NASA Astrophysics Data System (ADS)

    Gardner, C. A.; Pallister, J. S.

    2005-12-01

    The earthquake swarm beneath Mount St. Helens that began on 23 September 2004 did not initially appear different from previous swarms (none of which culminated in an eruption) that had occurred beneath the volcano since the end of the 1980-1986 eruptions. Three days into the swarm, however, a burst of larger-magnitude earthquakes indicated that this swarm was indeed different and prompted the U.S. Geological Survey's Cascades Volcano Observatory (CVO) to issue a change in alert level, the first time such a change had been issued in the Cascades in over 18 years. From then on, the unrest accelerated quickly as did the need to communicate the developing conditions to the public and public officials, often in the spotlight of intense media attention. Within three weeks of the onset of unrest, magma reached the surface. Since mid-October 2004, lava has been extruding through a glacier within the crater of Mount St. Helens, forming a 60 Mm3 dome by August 2005. The rapid onset of the eruption required a rapid ramping up of communication within and among the scientific, emergency-response and land-management communities, as well as the reestablishment of protocols that had not been rigorously tested for 18 years. Early on, daily meetings of scientists from CVO and the University of Washington's Pacific Northwest Seismograph Network were established to discuss incoming monitoring data and to develop a consensus on the likely course of activity, hazard potential and the uncertainty inherent in these forecasts. Subgroups developed scenario maps to describe the range of activity likely under different eruptive behaviors and sizes, and assessed short- and long-term probabilities of eruption, explosivity and hazardous events by employing a probability-tree methodology. Resultant consensual information has been communicated to a variety of groups using established alert levels for ground-based and aviation communities, daily updates and media briefings, postings on the

  3. Zircon from Mount St. Helens Reveals Residence Times of Tens to Hundreds of Thousands of Years at Low Magmatic Temperatures Prior to Eruption

    NASA Astrophysics Data System (ADS)

    Claiborne, L. L.; Miller, C. F.; Clynne, M. A.; Wooden, J. L.; Pallister, J. S.; Lowenstern, J. B.; Mazdab, F. K.

    2007-12-01

    U-series and U-Pb geochronology of zircons from four samples that span the 300,000 year eruptive history of Mount St. Helens, combined with zircon trace element geochemistry and application of the Ti-in-zircon thermometer, provide critical constraints on the time-temperature-compositional history of the sub-volcanic magmatic system. Preliminary results indicate that prior to and throughout its eruptive history, one or more relatively cool, crystal-rich reservoirs have been accumulating beneath the volcano. SHRIMP-RG U-Pb ages of the oldest sample, a dacite erupted ~300 ka, reveal that zircons grew between ~320 and 520 ka, suggesting magmatic activity may have begun 200 ka before eruption. 238U-230Th age spectra in the three youngest samples indicate multiple ages of growth for each sample. The oldest of these three young samples (eruption constrained to ~35-50 ka) contains zircons ranging from ~50 to ~200 ka, with the main concentration of ages ~100 ka. Zircons from a 35 ka dacite range from ~65 to ~230 ka in age, with a dominant episode of growth ~130 ka. Dacite from the current eruption, sampled from the dome in 2005, contains zircons from ~40 to ~170 ka in age, with distinct populations at ~130 and ~170 ka. Taken together, these ages of tens to hundreds of thousands of years prior to eruption and the distinct episodes of growth suggest repeated injection and accumulation of one or more crystal-rich reservoirs beneath the volcanic edifice, a scenario that is further supported by Ti-in-zircon geothermometry (Watson et al. 2006). Ti concentrations indicate zircons grew at temperatures from ~840 to ~640 C, with 90% of analyzed spots recording temperatures between ~770 and ~670 C (T's carry uncertainties of tens of degrees, mostly from uncertainty in a(TiO2)). These temperatures are significantly lower than the eruption temperatures of their host magmas, which range from ~950-800 C. The rounded, resorbed surface morphology of many of the grains attests to the

  4. Calculation of multicomponent chemical equilibria in gas-solid- liquid systems: calculation methods, thermochemical data, and applications to studies of high-temperature volcanic gases with examples from Mount St. Helens

    USGS Publications Warehouse

    Symonds, R.B.; Reed, M.H.

    1993-01-01

    This paper documents the numerical formulations, thermochemical data base, and possible applications of computer programs, SOLVGAS and GASWORKS, for calculating multicomponent chemical equilibria in gas-solid-liquid systems. SOLVGAS and GASWORKS compute simultaneous equilibria by solving simultaneously a set of mass balance and mass action equations written for all gas species and for all gas-solid or gas-liquid equilibria. Examples of gas-evaporation-from-magma and precipitation-with-cooling calculations for volcanic gases collected from Mount St. Helens are shown. -from Authors

  5. An investigation of vegetation and other Earth resource/feature parameters using LANDSAT and other remote sensing data. 1: LANDSAT. 2: Remote sensing of volcanic emissions. [New England forest and emissions from Mt. St. Helens and Central American volcanoes

    NASA Technical Reports Server (NTRS)

    Birnie, R. W.; Stoiber, R. E. (Principal Investigator)

    1981-01-01

    A fanning technique based on a simplistic physical model provided a classification algorithm for mixture landscapes. Results of applications to LANDSAT inventory of 1.5 million acres of forest land in Northern Maine are presented. Signatures for potential deer year habitat in New Hampshire were developed. Volcanic activity was monitored in Nicaragua, El Salvador, and Guatemala along with the Mt. St. Helens eruption. Emphasis in the monitoring was placed on the remote sensing of SO2 concentrations in the plumes of the volcanoes.

  6. Pyroclastic Flow (Post-)Emplacement Thermal History Derived From Titanomagnetite Curie Temperatures: Mt. St. Helens and Soufrière Hills as Test Cases

    NASA Astrophysics Data System (ADS)

    Bowles, J.; Jackson, M.; Lappe, S. C. L. L.; Solheid, P.; Stinton, A. J.

    2014-12-01

    Pumice blocks and ash matrix sampled from the 1980 pyroclastic flows at Mt. St. Helens and the 2010 flow at Soufrière Hills, Montserrat, display magnetic Curie temperatures (TC) that vary strongly with depth in the flow. We demonstrate that these TC variations result from variable degrees of cation ordering within Mg- and Al-bearing titanomagnetites, and that the degree of ordering is dependent on the emplacement temperature and post-emplacement thermal history of the sample. Curie temperatures are lowest at the tops of flows where rapid cooling has quenched in a relatively low degree of cation order. Samples that cooled more slowly at depth in the flow evolved towards a higher degree of cation order with a correspondingly higher TC. Isothermal annealing experiments in the laboratory have allowed us to document the time-temperature evolution of the cation ordering and Curie temperature, and we use this data in combination with conductive cooling calculations to forward model stratigraphic variations in TC as a function of emplacement temperature (e.g., Fig.1). Preliminary results show that modeled emplacement temperatures (Templ) are reasonably close to measured or estimated emplacement temperatures. Thermal demagnetization data from lithic clasts incorporated into some flows supports the modeled emplacement temperatures; a low-temperature overprint in the direction of the present-day field is removed at ~Templ. However, the documented variation of TC with thermal history means that care should be taken in interpreting this more traditional lithic-based paleomagnetic paleothermometry data. Modification of Curie and blocking temperatures both during natural cooling and during laboratory thermal treatments could affect lithic-based emplacement temperature estimates.

  7. Source mechanism of small long-period events at Mount St. Helens in July 2005 using template matching, phase-weighted stacking, and full-waveform inversion

    USGS Publications Warehouse

    Matoza, Robin S.; Chouet, Bernard A.; Dawson, Phillip B.; Shearer, Peter M.; Haney, Matthew M.; Waite, Gregory P.; Moran, Seth C.; Mikesell, T. Dylan

    2015-01-01

    Long-period (LP, 0.5-5 Hz) seismicity, observed at volcanoes worldwide, is a recognized signature of unrest and eruption. Cyclic LP “drumbeating” was the characteristic seismicity accompanying the sustained dome-building phase of the 2004–2008 eruption of Mount St. Helens (MSH), WA. However, together with the LP drumbeating was a near-continuous, randomly occurring series of tiny LP seismic events (LP “subevents”), which may hold important additional information on the mechanism of seismogenesis at restless volcanoes. We employ template matching, phase-weighted stacking, and full-waveform inversion to image the source mechanism of one multiplet of these LP subevents at MSH in July 2005. The signal-to-noise ratios of the individual events are too low to produce reliable waveform-inversion results, but the events are repetitive and can be stacked. We apply network-based template matching to 8 days of continuous velocity waveform data from 29 June to 7 July 2005 using a master event to detect 822 network triggers. We stack waveforms for 359 high-quality triggers at each station and component, using a combination of linear and phase-weighted stacking to produce clean stacks for use in waveform inversion. The derived source mechanism pointsto the volumetric oscillation (~10 m3) of a subhorizontal crack located at shallow depth (~30 m) in an area to the south of Crater Glacier in the southern portion of the breached MSH crater. A possible excitation mechanism is the sudden condensation of metastable steam from a shallow pressurized hydrothermal system as it encounters cool meteoric water in the outer parts of the edifice, perhaps supplied from snow melt.

  8. Source mechanism of small long-period events at Mount St. Helens in July 2005 using template matching, phase-weighted stacking, and full-waveform inversion

    NASA Astrophysics Data System (ADS)

    Matoza, Robin S.; Chouet, Bernard A.; Dawson, Phillip B.; Shearer, Peter M.; Haney, Matthew M.; Waite, Gregory P.; Moran, Seth C.; Mikesell, T. Dylan

    2015-09-01

    Long-period (LP, 0.5-5 Hz) seismicity, observed at volcanoes worldwide, is a recognized signature of unrest and eruption. Cyclic LP "drumbeating" was the characteristic seismicity accompanying the sustained dome-building phase of the 2004-2008 eruption of Mount St. Helens (MSH), WA. However, together with the LP drumbeating was a near-continuous, randomly occurring series of tiny LP seismic events (LP "subevents"), which may hold important additional information on the mechanism of seismogenesis at restless volcanoes. We employ template matching, phase-weighted stacking, and full-waveform inversion to image the source mechanism of one multiplet of these LP subevents at MSH in July 2005. The signal-to-noise ratios of the individual events are too low to produce reliable waveform inversion results, but the events are repetitive and can be stacked. We apply network-based template matching to 8 days of continuous velocity waveform data from 29 June to 7 July 2005 using a master event to detect 822 network triggers. We stack waveforms for 359 high-quality triggers at each station and component, using a combination of linear and phase-weighted stacking to produce clean stacks for use in waveform inversion. The derived source mechanism points to the volumetric oscillation (˜10 m3) of a subhorizontal crack located at shallow depth (˜30 m) in an area to the south of Crater Glacier in the southern portion of the breached MSH crater. A possible excitation mechanism is the sudden condensation of metastable steam from a shallow pressurized hydrothermal system as it encounters cool meteoric water in the outer parts of the edifice, perhaps supplied from snow melt.

  9. Operation of a digital seismic network on Mount St. Helens volcano and observations of long period seismic events that originate under the volcano

    SciTech Connect

    Fehler, M.; Chouet, B.

    1982-09-01

    A 9 station digital seismic array was operated on Mount St. Helens volcano in Washington State during 1981. One of the stations was placed inside the crater of the volcano, six were located on the flanks of the volcano within two km of the crater and two were approximately ten km from the crater. Four of the instruments recorded three components of motion and the remaining five recorded only the vertical component. A one day experiment was carried out during which the crater monitoring seismometer was complimented by the addition of two ink recording instruments. During the one day experiment six observers recorded times of rockfall, felt-earthquake occurrences, and changes in steam emissions from the dome in the crater. Using information obtained during the one day experiment seismic events recorded by the digital instruments were classified as earthquakes, rockfalls, helicopter noise and a type of event that is unique to volcanoes which is called long period. Waveforms of these long period events have a duration of up to 30 seconds and a spectrum that is peaked at approximately 2 Hz. The frequency at which the peak in the spectrum occurs is nearly the same at all stations which means that the unique waveform of long period events is due to a source effect, not a path effect. The peak frequency is fairly insensitive to the amplitude of the signal which means that the size of the source region is constant, independent of the signal amplitude. Long period events were not felt and were accompanied by no visible changes inside the crater which lead to the conclusion that they are some sort of seismic disturbance generated inside the Volcano.

  10. Digital Elevation Models of the Pre-Eruption 2000 Crater and 2004-07 Dome-Building Eruption at Mount St. Helens, Washington, USA

    USGS Publications Warehouse

    Messerich, J.A.; Schilling, S.P.; Thompson, R.A.

    2008-01-01

    Presented in this report are 27 digital elevation model (DEM) datasets for the crater area of Mount St. Helens. These datasets include pre-eruption baseline data collected in 2000, incremental model subsets collected during the 2004-07 dome building eruption, and associated shaded-relief image datasets. Each dataset was collected photogrammetrically with digital softcopy methods employing a combination of manual collection and iterative compilation of x,y,z coordinate triplets utilizing autocorrelation techniques. DEM data points collected using autocorrelation methods were rigorously edited in stereo and manually corrected to ensure conformity with the ground surface. Data were first collected as a triangulated irregular network (TIN) then interpolated to a grid format. DEM data are based on aerotriangulated photogrammetric solutions for aerial photograph strips flown at a nominal scale of 1:12,000 using a combination of surveyed ground control and photograph-identified control points. The 2000 DEM is based on aerotriangulation of four strips totaling 31 photographs. Subsequent DEMs collected during the course of the eruption are based on aerotriangulation of single aerial photograph strips consisting of between three and seven 1:12,000-scale photographs (two to six stereo pairs). Most datasets were based on three or four stereo pairs. Photogrammetric errors associated with each dataset are presented along with ground control used in the photogrammetric aerotriangulation. The temporal increase in area of deformation in the crater as a result of dome growth, deformation, and translation of glacial ice resulted in continual adoption of new ground control points and abandonment of others during the course of the eruption. Additionally, seasonal snow cover precluded the consistent use of some ground control points.

  11. N-P Co-Limitation of Primary Production and Response of Arthropods to N and P in Early Primary Succession on Mount St. Helens Volcano

    PubMed Central

    Bishop, John G.; O'Hara, Niamh B.; Titus, Jonathan H.; Apple, Jennifer L.; Gill, Richard A.; Wynn, Louise

    2010-01-01

    Background The effect of low nutrient availability on plant-consumer interactions during early succession is poorly understood. The low productivity and complexity of primary successional communities are expected to limit diversity and abundance of arthropods, but few studies have examined arthropod responses to enhanced nutrient supply in this context. We investigated the effects of nitrogen (N) and phosphorus (P) addition on plant productivity and arthropod abundance on 24-yr-old soils at Mount St. Helens volcano. Methodology/Principal Findings We measured the relative abundance of eight arthropod orders and five families in plots that received N, P, or no nutrients for 3–5 years. We also measured plant % cover, leaf %N, and plant diversity. Vegetation responded rapidly to N addition but showed a lagged response to P that, combined with evidence of increased N fixation, suggested P-limitation to N availability. After 3 yrs of fertilization, orthopterans (primarily Anabrus simplex (Tettigoniidae) and Melanoplus spp (Acrididae)) showed a striking attraction to P addition plots, while no other taxa responded to fertilization. After 5 yrs of fertilization, orthopteran density in the same plots increased 80%–130% with P addition and 40% with N. Using structural equation modeling, we show that in year 3 orthopteran abundance was associated with a P-mediated increase in plant cover (or correlated increases in resource quality), whereas in year 5 orthopteran density was not related to cover, diversity or plant %N, but rather to unmeasured effects of P, such as its influence on other aspects of resource quality. Conclusions/Significance The marked surprising response to P by orthopterans, combined with a previous observation of P-limitation in lepidopteran herbivores at these sites, suggests that P-mediated effects of food quantity or quality are critical to insect herbivores in this N-P co-limited primary successional system. Our results also support a previous

  12. A New Perspective on Mount St. Helens - Dramatic Landform Change and Associated Hazards at the Most Active Volcano in the Cascade Range

    USGS Publications Warehouse

    Ramsey, David W.; Driedger, Carolyn L.; Schilling, Steve P.

    2008-01-01

    Mount St. Helens has erupted more frequently than any other volcano in the Cascade Range during the past 4,000 years. The volcano has exhibited a variety of eruption styles?explosive eruptions of pumice and ash, slow but continuous extrusions of viscous lava, and eruptions of fluid lava. Evidence of the volcano?s older eruptions is recorded in the rocks that build and the deposits that flank the mountain. Eruptions at Mount St. Helens over the past three decades serve as reminders of the powerful geologic forces that are reshaping the landscape of the Pacific Northwest. On May 18, 1980, a massive landslide and catastrophic explosive eruption tore away 2.7 cubic kilometers of the mountain and opened a gaping, north-facing crater. Lahars flowed more than 120 kilometers downstream, destroying bridges, roads, and buildings. Ash from the eruption fell as far away as western South Dakota. Reconstruction of the volcano began almost immediately. Between 1980 and 1986, 80 million cubic meters of viscous lava extruded episodically onto the crater floor, sometimes accompanied by minor explosions and small lahars. A lava dome grew to a height of 267 meters, taller than the highest buildings in the nearby city of Portland, Oregon. Crater Glacier formed in the deeply shaded niche between the 1980-86 lava dome and the south crater wall. Its tongues of ice flowed around the east and west sides of the dome. Between 1989 and 1991, multiple explosions of steam and ash rocked the volcano, possibly a result of infiltrating rainfall being heated in the still-hot interior of the dome and underlying crater floor. In September 2004, rising magma caused earthquake swarms and deformation of the crater floor and glacier, which indicated that Mount St. Helens might erupt again soon. On October 1, 2004, a steam and ash explosion signaled the beginning of a new phase of eruptive activity at the volcano. On October 11, hot rock reached the surface and began building a new lava dome immediately

  13. Instrumentation in remote and dangerous settings; examples using data from GPS “spider” deployments during the 2004-2005 eruption of Mount St. Helens, Washington: Chapter 16 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

    USGS Publications Warehouse

    LaHusen, Richard G.; Swinford, Kelly J.; Logan, Matthew; Lisowski, Michael; Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

    2008-01-01

    Self-contained, single-frequency GPS instruments fitted on lightweight stations suitable for helicopter-sling payloads became a critical part of volcano monitoring during the September 2004 unrest and subsequent eruption of Mount St. Helens. Known as “spiders” because of their spindly frames, the stations were slung into the crater 29 times from September 2004 to December 2005 when conditions at the volcano were too dangerous for crews to install conventional equipment. Data were transmitted in near-real time to the Cascades Volcano Observatory in Vancouver, Washington. Each fully equipped unit cost about $2,500 in materials and, if not destroyed by natural events, was retrieved and redeployed as needed. The GPS spiders have been used to track the growth and decay of extruding dacite lava (meters per day), thickening and accelerated flow of Crater Glacier (meters per month), and movement of the 1980-86 dome from pressure and relaxation of the newly extruding lava dome (centimeters per day).

  14. Using semi-automated photogrammetry software to generate 3D surfaces from oblique and vertical photographs at Mount St. Helens, WA

    NASA Astrophysics Data System (ADS)

    Schilling, S.; Diefenbach, A. K.

    2012-12-01

    Photogrammetry has been used to generate contours and Digital Elevation Models (DEMs) to monitor change at Mount St. Helens, WA since the 1980 eruption. We continue to improve techniques to monitor topographic changes within the crater. During the 2004-2008 eruption, 26 DEMs were used to track volume and rates of growth of a lava dome and changes of Crater Glacier. These measurements constrained seismogenic extrusion models and were compared with geodetic deflation volume to constrain magma chamber behavior. We used photogrammetric software to collect irregularly spaced 3D points primarily by hand and, in reasonably flat areas, by automated algorithms, from commercial vertical aerial photographs. These models took days to months to complete and the areal extent of each surface was determined by visual inspection. Later in the eruption, we pioneered the use of different software to generate irregularly spaced 3D points manually from oblique images captured by a hand-held digital camera. In each case, the irregularly spaced points and intervening interpolated points formed regular arrays of cells or DEMs. Calculations using DEMs produced from the hand-held images duplicated volumetric and rate results gleaned from the vertical aerial photographs. This manual point capture technique from oblique hand-held photographs required only a few hours to generate a model over a focused area such as the lava dome, but would have taken perhaps days to capture data over the entire crater. Here, we present results from new photogrammetric software that uses robust image-matching algorithms to produce 3D surfaces automatically after inner, relative, and absolute orientations between overlapping photographs are completed. Measurements using scans of vertical aerial photographs taken August 10, 2005 produced dome volume estimates within two percent of those from a surface generated using the vertical aerial photograph manual method. The new August 10th orientations took less than 8

  15. Analysis of long-period seismic waves excited by the May 18, 1980, eruption of Mount St. Helens: a terrestrial monopole

    SciTech Connect

    Kanamori, H.; Given, J.W.

    1982-07-10

    Long-period (100 to 260 s) Love and Rayleigh waves excited by the eruption of Mount St. Helens on May 18, 1980, and recorded by ID, SRO, and ASRO stations were analyzed to determine the mechanism of the eruption. The amplitude radiation patterns of both Rayleigh and Love waves are two lobed with nodal direction in E5/sup 0/S for Rayleigh waves and in N5/sup 0/E for Love waves. These radiation patterns preclude any double-couple mechanism. The radiation pattern, the initial phase, the relatively large amplitude ratio of Love to Rayleigh waves and the existence of clear nodes in the radiation patterns of fundamental mode and higher-mode Rayleigh waves suggest that the source is represented by an almost horizontal (less than 15/sup 0/ from the horizontal) single force pointed toward S5/sup 0/W. The surface wave spectra fall off very rapidly at periods shorter than 75 s suggesting a very slow source process. Although the details of the source time history could not be determined, a smooth bell-shaped time function: f/sub 0/s(t) = (1/2)f/sub 0/(1-cos( (t)/(tau) ..pi..)) for 0< or =t< or =2tau and f/sub 0/s(t) = 0 for t> or =2tau, with tau = 75 s is considered appropriate on the basis of comparison between synthetic and observed seismograms and of the shape of the source spectrum. The peak value of the force f/sub 0/ is about 10/sup 18/ dynes. The tailing end of the source time function could not be resolved, and some overshoot may be added. The magnitude and the time history of the force can be explained by a northward landslide followed by a lateral blast observed at the time of the eruption. Two distinct events about 110 apart can be identified on body wave and short-period surface wave records. The first event may correspond to the earthquake which triggered the landslide and the lateral blast. The second event appears to correspond to a second large earthquake and explosion which took place about 2 minutes after the first earthquake.

  16. Interrelations among pyroclastic surge, pyroclastic flow, and lahars in Smith Creek valley during first minutes of 18 May 1980 eruption of Mount St. Helens, USA

    USGS Publications Warehouse

    Brantley, S.R.; Waitt, R.B.

    1988-01-01

    A devastating pyroclastic surge and resultant lahars at Mount St. Helens on 18 May 1980 produced several catastrophic flowages into tributaries on the northeast volcano flank. The tributaries channeled the flows to Smith Creek valley, which lies within the area devastated by the surge but was unaffected by the great debris avalanche on the north flank. Stratigraphy shows that the pyroclastic surge preceded the lahars; there is no notable "wet" character to the surge deposits. Therefore the lahars must have originated as snowmelt, not as ejected water-saturated debris that segregated from the pyroclastic surge as has been inferred for other flanks of the volcano. In stratigraphic order the Smith Creek valley-floor materials comprise (1) a complex valley-bottom facies of the pyroclastic surge and a related pyroclastic flow, (2) an unusual hummocky diamict caused by complex mixing of lahars with the dry pyroclastic debris, and (3) deposits of secondary pyroclastic flows. These units are capped by silt containing accretionary lapilli, which began falling from a rapidly expanding mushroom-shaped cloud 20 minutes after the eruption's onset. The Smith Creek valley-bottom pyroclastic facies consists of (a) a weakly graded basal bed of fines-poor granular sand, the deposit of a low-concentration lithic pyroclastic surge, and (b) a bed of very poorly sorted pebble to cobble gravel inversely graded near its base, the deposit of a high-concentration lithic pyroclastic flow. The surge apparently segregated while crossing the steep headwater tributaries of Smith Creek; large fragments that settled from the turbulent surge formed a dense pyroclastic flow along the valley floor that lagged behind the front of the overland surge. The unusual hummocky diamict as thick as 15 m contains large lithic clasts supported by a tough, brown muddy sand matrix like that of lahar deposits upvalley. This unit contains irregular friable lenses and pods meters in diameter, blocks incorporated from

  17. High-resolution digital elevation model of lower Cowlitz and Toutle Rivers, adjacent to Mount St. Helens, Washington, based on an airborne lidar survey of October 2007

    USGS Publications Warehouse

    Mosbrucker, Adam

    2015-01-01

    The lateral blast, debris avalanche, and lahars of the May 18th, 1980, eruption of Mount St. Helens, Washington, dramatically altered the surrounding landscape. Lava domes were extruded during the subsequent eruptive periods of 1980–1986 and 2004–2008. More than three decades after the emplacement of the 1980 debris avalanche, high sediment production persists in the Toutle River basin, which drains the northern and western flanks of the volcano. Because this sediment increases the risk of flooding to downstream communities on the Toutle and lower Cowlitz Rivers, the U.S. Army Corps of Engineers (USACE), under the direction of Congress to maintain an authorized level of flood protection, continues to monitor and mitigate excess sediment in North and South Fork Toutle River basins to help reduce this risk and to prevent sediment from clogging the shipping channel of the Columbia River. From October 22–27, 2007, Watershed Sciences, Inc., under contract to USACE, collected high-precision airborne lidar (light detection and ranging) data that cover 273 square kilometers (105 square miles) of lower Cowlitz and Toutle River tributaries from the Columbia River at Kelso, Washington, to upper North Fork Toutle River (below the volcano's edifice), including lower South Fork Toutle River. These data provide a digital dataset of the ground surface, including beneath forest cover. Such remotely sensed data can be used to develop sediment budgets and models of sediment erosion, transport, and deposition. The U.S. Geological Survey (USGS) used these lidar data to develop digital elevation models (DEMs) of the study area. DEMs are fundamental to monitoring natural hazards and studying volcanic landforms, fluvial and glacial geomorphology, and surface geology. Watershed Sciences, Inc., provided files in the LASer (LAS) format containing laser returns that had been filtered, classified, and georeferenced. The USGS produced a hydro-flattened DEM from ground-classified points at

  18. Immediate public health concerns and actions in volcanic eruptions: lessons from the Mount St. Helens eruptions, May 18-October 18, 1980.

    PubMed Central

    Bernstein, R S; Baxter, P J; Falk, H; Ing, R; Foster, L; Frost, F

    1986-01-01

    A comprehensive epidemiological evaluation of mortality and short-term morbidity associated with explosive volcanic activity was carried out by the Centers for Disease Control in collaboration with affected state and local health departments, clinicians, and private institutions. Following the May 18, 1980 eruption of Mount St. Helens, a series of public health actions were rapidly instituted to develop accurate information about volcanic hazards and to recommend methods for prevention or control of adverse effects on safety and health. These public health actions included: establishing a system of active surveillance of cause-specific emergency room (ER) visits and hospital admissions in affected and unaffected communities for comparison; assessing the causes of death and factors associated with survival or death among persons located near the crater; analyzing the mineralogy and toxicology of sedimented ash and the airborne concentration of resuspended dusts; investigating reported excesses of ash-related adverse respiratory effects by epidemiological methods such as cross-sectional and case-control studies; and controlling rumors and disseminating accurate, timely information about volcanic hazards and recommended preventive or control measures by means of press briefings and health bulletins. Surveillance and observational studies indicated that: excess in morbidity were limited to transient increases in ER visits and hospital admissions for traumatic injuries and respiratory problems (but not for communicable disease or mental health problems) which were associated in time, place, and person with exposures to volcanic ash; excessive mortality due to suffocation (76 per cent), thermal injuries (12 per cent), or trauma (12 per cent) by ash and other volcanic hazards was directly proportional to the degree of environmental damage--that is, it was more pronounced among those persons (48/65, or about 74 per cent) who, at the time of the eruption, were residing

  19. Hydrogen isotope investigation of amphibole and glass in dacite magmas erupted in 1980-1986 and 2005 at Mount St. Helens, Washington

    USGS Publications Warehouse

    Underwood, S.J.; Feeley, T.C.; Clynne, M.A.

    2013-01-01

    In active, shallow, sub-volcanic magma conduits the extent of the dehydrogenation–oxidation reaction in amphibole phenocrysts is controlled by energetic processes that cause crystal lattice damage or conditions that increase hydrogen diffusivity in magmatic phases. Amphibole phenocrysts separated from dacitic volcanic rocks erupted from 1980 to 1986 and in 2005 at Mount St. Helens (MSH) were analyzed for δD, water content and Fe3+/Fe2+, and fragments of glassy groundmass were analyzed for δD and water content. Changes in amphibole δD values through time are evaluated within the context of carefully observed volcanic eruption behavior and published petrological and geochemical investigations. Driving forces for amphibole dehydrogenation include increase in magma oxygen fugacity, decrease in amphibole hydrogen fugacity, or both. The phenocryst amphibole (δD value c. –57‰ and 2 wt % H2O) in the white fallout pumice of the May 18, 1980 plinian eruptive phase is probably little modified during rapid magma ascent up an ∼7 km conduit. Younger volcanic rocks incorporate some shallowly degassed dacitic magma from earlier pulses, based on amphibole phenocryst populations that exhibit varying degrees of dehydrogenation. Pyroclastic rocks from explosive eruptions in June–October 1980 have elevated abundances of mottled amphibole phenocrysts (peaking in some pyroclastic rocks erupted on July 22, 1980), and extensive amphibole dehydrogenation is linked to crystal damage from vesiculation and pyroclastic fountain collapse that increased effective hydrogen diffusion in amphibole. Multiple amphibole δD populations in many 1980 pyroclastic rocks combined with their groundmass characteristics (e.g. mixed pumice textures) support models of shallow mixing prior to, or during, eruption as new, volatile-rich magma pulses blended with more oxidized, degassed magma. Amphibole dehydrogenation is quenched at the top surface of MSH dacite lava lobes, but the diversity in the

  20. Calculation of multicomponent chemical equilibria in gas-solid-liquid systems: Calculation methods, thermochemical data, and applications to studies of high-temperature volcanic gases with examples from Mt. St. Helens

    SciTech Connect

    Symonds, R.B. ); Reed, M.H. )

    1993-10-01

    This paper documents the numerical formulations, thermochemical data base, and possible applications of computer programs, SOLVGAS and GASWORKS, for calculating multicomponent chemical equilibria in gas-solid-liquid systems. SOLVGAS and GASWORKS compute simultaneous equilibria by solving simultaneously a set of mass balance and mass action equations written for all gas species and for all gas-solid or gas-liquid equilibria. The programs interface with a thermo-chemical data base, GASTHERM, which contains coefficients for retrieval of the equilibrium constants from 25[degrees] to 1200[degrees]C. The programs and data base model dynamic chemical processes in 30- to 40-component volcanic-gas systems. The authors can model gas evaporation from magma, mixing of magmatic and hydrothermal gases, precipitation of minerals during pressure and temperature decrease, mixing of volcanic gas with air, and reaction of gases with wall rock. Examples are given of the gas-evaporation-from-magma and precipitation-with-cooling calculations for volcanic gases collected from Mt. St. Helens in September 1981. The authors predict: (1) the amounts of trace elements volatilized from shallow magma, deep magma, and wall rock, and (2) the solids that precipitate from the gas upon cooling. The predictions are tested by comparing them with the measured trace-element concentrations in gases and the observed sublimate sequence. This leads to the following conclusions: (1) most of the trace elements in the Mt. St. Helens gases are volatilized from shallow magma as simple chlorides; (2) some elements (for example, Al, Ca) exist dominantly in rock aerosols, not gases, in the gas stream; (3) near-surface cooling of the gases triggers precipitation of oxides, sulfides, halides, tungstates, and native elements; and (4) equilibrium cooling of the gases to 100[degrees]C causes most trace elements, except for Hg, Sb, and Se, to precipitate from the gas. 94 refs., 30 figs., 7 tabs.

  1. Evaluating turbidity and suspended-sediment concentration relations from the North Fork Toutle River basin near Mount St. Helens, Washington; annual, seasonal, event, and particle size variations - a preliminary analysis.

    USGS Publications Warehouse

    Uhrich, Mark A.; Spicer, Kurt R.; Mosbrucker, Adam; Christianson, Tami

    2015-01-01

    Regression of in-stream turbidity with concurrent sample-based suspended-sediment concentration (SSC) has become an accepted method for producing unit-value time series of inferred SSC (Rasmussen et al., 2009). Turbidity-SSC regression models are increasingly used to generate suspended-sediment records for Pacific Northwest rivers (e.g., Curran et al., 2014; Schenk and Bragg, 2014; Uhrich and Bragg, 2003). Recent work developing turbidity-SSC models for the North Fork Toutle River in Southwest Washington (Uhrich et al., 2014), as well as other studies (Landers and Sturm, 2013, Merten et al., 2014), suggests that models derived from annual or greater datasets may not adequately reflect shorter term changes in turbidity-SSC relations, warranting closer inspection of such relations. In-stream turbidity measurements and suspended-sediment samples have been collected from the North Fork Toutle River since 2010. The study site, U.S. Geological Survey (USGS) streamgage 14240525 near Kid Valley, Washington, is 13 river km downstream of the debris avalanche emplaced by the 1980 eruption of Mount St. Helens (Lipman and Mullineaux, 1981), and 2 river km downstream of the large sediment retention structure (SRS) built from 1987–1989 to mitigate the associated sediment hazard. The debris avalanche extends roughly 25 km down valley from the edifice of the volcano and is the primary source of suspended sediment moving past the streamgage (NF Toutle-SRS). Other significant sources are debris flow events and sand deposits upstream of the SRS, which are periodically remobilized and transported downstream. Also, finer material often is derived from the clay-rich original debris avalanche deposit, while coarser material can derive from areas such as fluvially reworked terraces.

  2. Sequential fragmentation/transport theory, pyroclast size-density relationships, and the emplacement dynamics of pyroclastic density currents — A case study on the Mt. St. Helens (USA) 1980 eruption

    NASA Astrophysics Data System (ADS)

    Mackaman-Lofland, Chelsea; Brand, Brittany D.; Taddeucci, Jacopo; Wohletz, Kenneth

    2014-04-01

    Pyroclastic density currents (PDCs) are the most dangerous hazard associated with explosive volcanic eruptions. Despite recent advancements in the general understanding of PDC dynamics, limited direct observation and/or outcrop scarcity often hinder the interpretation of specific transport and depositional processes at many volcanoes. This study explores the potential of sequential fragmentation/transport theory (SFT; cf. Wohletz et al., 1989), a modeling method capable of predicting particle mass distributions based on the physical principles of fragmentation and transport, to retrieve the transport and depositional dynamics of well-characterized PDCs from the size and density distributions of individual components within the deposits. The extensive vertical and lateral exposures through the May 18th, 1980 PDC deposits at Mt. St. Helens (MSH) provide constraints on PDC regimes and flow boundary conditions at specific locations across the depositional area. Application to MSH deposits suggests that SFT parameter distributions can be effectively used to characterize flow boundary conditions and emplacement processes for a variety of PDC lithofacies and deposit locations. Results demonstrate that (1) the SFT approach reflects particle fragmentation and transport mechanisms regardless of variations in initial component distributions, consistent with results from previous studies; (2) SFT analysis reveals changes in particle characteristics that are not directly observable in grain size and fabric data; and (3) SFT parameters are more sensitive to regional transport conditions than local (outcrop-scale) depositional processes. The particle processing trends produced using SFT analysis are consistent with the degree of particle processing inferred from lithofacies architectures: for all lithofacies examined in this study, suspension sedimentation products exhibit much better processing than concentrated current deposits. Integrated field observations and SFT results

  3. Maps, Plates, and Mount Saint Helens.

    ERIC Educational Resources Information Center

    Lary, Barbara E.; Krockover, Gerald H.

    1987-01-01

    Describes a laboratory activity on plate tectonics which focuses on the connection between plate tectonics and the different types of volcanoes. Provides questions for discussion and includes suggestions for extending the activity. (ML)

  4. Directed blasts and blast-generated pyroclastic density currents: a comparison of the Bezymianny 1956, Mount St Helens 1980, and Soufrière Hills, Montserrat 1997 eruptions and deposits

    USGS Publications Warehouse

    Belousov, Alexander; Voight, Barry; Belousova, Marina

    2007-01-01

    We compare eruptive dynamics, effects and deposits of the Bezymianny 1956 (BZ), Mount St Helens 1980 (MSH), and Soufrière Hills volcano, Montserrat 1997 (SHV) eruptions, the key events of which included powerful directed blasts. Each blast subsequently generated a high-energy stratified pyroclastic density current (PDC) with a high speed at onset. The blasts were triggered by rapid unloading of an extruding or intruding shallow magma body (lava dome and/or cryptodome) of andesitic or dacitic composition. The unloading was caused by sector failures of the volcanic edifices, with respective volumes for BZ, MSH, and SHV c. 0.5, 2.5, and 0.05 km3 . The blasts devastated approximately elliptical areas, axial directions of which coincided with the directions of sector failures. We separate the transient directed blast phenomenon into three main parts, the burst phase, the collapse phase, and the PDC phase. In the burst phase the pressurized mixture is driven by initial kinetic energy and expands rapidly into the atmosphere, with much of the expansion having an initially lateral component. The erupted material fails to mix with sufficient air to form a buoyant column, but in the collapse phase, falls beyond the source as an inclined fountain, and thereafter generates a PDC moving parallel to the ground surface. It is possible for the burst phase to comprise an overpressured jet, which requires injection of momentum from an orifice; however some exploding sources may have different geometry and a jet is not necessarily formed. A major unresolved question is whether the preponderance of strong damage observed in the volcanic blasts should be attributed to shock waves within an overpressured jet, or alternatively to dynamic pressures and shocks within the energetic collapse and PDC phases. Internal shock structures related to unsteady flow and compressibility effects can occur in each phase. We withhold judgment about published shock models as a primary explanation for the

  5. The Affirmative Approach: An Interview with Helen Hosmer.

    ERIC Educational Resources Information Center

    Deans, Karen

    1984-01-01

    Hosmer, dean emeritus of Crane School of Music, a department of the State University of Arts and Science at Potsdam, New York, discusses her life, her teaching experiences, changes in college students over the years, and the state of music education. (RM)

  6. St Helens EAZ: Creative Learning/Collaborative Leadership Project

    ERIC Educational Resources Information Center

    Gkolia, Chrysanthi; Switzer, Jackie; Brundrett, Mark

    2006-01-01

    Education Action Zones (EAZs) have formed one of the key elements of government policy in trying to drive up standards and disseminate best practice. However, the initiative has been subject to a sustained critique and questions have remained as to the efficacy of such networks of schools. This article offers a brief report on an evaluative study…

  7. Variety in Play: Exploring Photographs by Helen Levitt

    ERIC Educational Resources Information Center

    Ruich, Lawrence J.

    2012-01-01

    Children and burgeoning adolescents' creativity blossom in play-based environments. Likewise, students as active social agents have the opportunity to examine the structures and processes that shape them. The photographic image intimates an aura of credibility, providing the students pause to reflect upon their socialized interactions. These…

  8. Stratospheric CCN sampling program. [volcanology, Mount Saint Helens

    NASA Technical Reports Server (NTRS)

    Rogers, C. F.; Hudson, J. G.

    1982-01-01

    Two one liter grab samples of stratospheric aerosol were returned from each of six U-2 sampling missions. Cloud condensation nuclei (CCN) spectra from each sample were obtained. Interest was centered on the effects of volcanic activity. Spurious particle generation was found to be a serious problem in container 9 LFT and a much smaller problem in container 9 RT. Initial studies of an option for improved sample containers and values were completed. A CCN spectrometer, able to operate at an internal pressure of 300 mb, was designed.

  9. The 100 Is There! Helen Gordon Child Development Center

    ERIC Educational Resources Information Center

    Reinisch, Sheryl; Parnell, Will

    2006-01-01

    As teacher educators, the authors visit numerous learning environments. Each school has its own unique characteristics and personality. Some schools seem to have a magnetic draw, filling the senses with energy, wonder and intrigue. This energy, writes the authors, stems from a symbiotic relationship, a flow of spaces that work together…

  10. Magnetic fields in astrophysics /Helen B. Warner Prize Lecture/

    NASA Astrophysics Data System (ADS)

    Blandford, R. D.

    1983-03-01

    Magnetic fields play many important roles in interpretative models of astronomical phenomena. They can provide diagnostics of the physical conditions within active objects. They may mediate and collimate the energy release from a deep gravitational potential well. On a microscopic level, they may control the transport properties of astrophysical plasmas with large-scale thermal and dynamical consequences. Some of these facets of the behavior of magnetic fields are illustrated with examples drawn mainly from contemporary high-energy astrophysics. In particular, attention is given to the case that most double radio sources are powered by the electromagnetic or hydromagnetic extraction of energy from a spinning massive black hole and accretion disk and subsequently collimated by the pinching action of toroidal field wrapped around the jet. The origin of neutron star magnetic field is also discussed and it is argued that the magnetization can be generated thermoelectrically by the heat flux escaping from the interior of the star.

  11. In Conversation with Helen Dorr and Vicki Raphael

    ERIC Educational Resources Information Center

    Holman, Andrew

    2006-01-01

    There is a new National Family Carer Network putting the views across of family carers. They believe family carers have often been given a bad name. Family carers now have more places on the Learning Disability TaskForce, but will it do any better than before? New laws about who can make decisions will help, if they don't imply that parents are…

  12. Small explosions interrupt 3-year quiescence at Mount St. Helens, Washington

    USGS Publications Warehouse

    Myers, B.

    1992-01-01

    These ash-producing explosions are part of a series of at least 28 explosion-like seismic events that began on August 24, 989. Seismic signals from these events resemble those associated with confirmed ash-producing explosions in April-May 1986. Yet not all of the 1989-1991 events produced ash plumes. Excellent visual observations during four of the events indicated that neither a steam nor ash plume was generated. There is little information about the other events because they occurred when the mountain was not visible, nor was there physical evidence of ashfall or surface changes when scientists visited the crater days to weeks alter. Considerable deformation of the north side of the dome occurred during the series of explosion-like seismic events. Sections of the dome slumped northward and two new vents were formed. However, monitoring the changes associated with individual events was often impossible because several key electronic-distance-meter (EDM) targets and tiltmeters were destroyed by the series of events. 

  13. Contrasting a non-developing African mesoscale convective system with the precursor to Hurricane Helene (2006)

    NASA Astrophysics Data System (ADS)

    Rivera, G.; Fuentes, J. D.; Evans, J. L.; Hamilton, H. L.

    2015-12-01

    Mesoscale convective systems (MCSs) in West Africa traverse strong thermodynamic gradients during their westward propagation from land to ocean. Some of the systems continue to develop after crossing the coastline and may ultimately develop into tropical cyclones, while others do not. Understanding the lifecycle behavior of these convective systems and the factors that contribute to their continuous development as they transition from a continental environment to a marine environment poses a challenge. We examine the difference between two MCSs, one that continued to develop when it crossed the West African coast and one that did not, using European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA Interim) and Tropical Rainfall Measurement Mission (TRMM) 3B42 data. The non-developing MCS that intensified briefly while over land, weakened as soon as it crossed the coast. Preliminary results show that the developing MCS interacted with two cyclonic vortices, one associated with an African Easterly Wave that was propagating towards the coast and the other vortex generated by the topography near the coast.

  14. 78 FR 43064 - Safety Zone; Maritime Heritage Festival Fireworks, St. Helens, OR

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-19

    ... DHS Department of Homeland Security FR Federal Register NPRM Notice of Proposed Rulemaking A... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Maritime Heritage Festival Fireworks, St... maritime public during a planned fireworks display and will do so by prohibiting unauthorized persons...

  15. Targeting geothermal exploration sites in the Mount St. Helens area using soil mercury surveys

    SciTech Connect

    Holmes, J.; Waugh, K.

    1983-11-01

    The background mercury level was determined for the areas studied, providing preliminary information for future work. Identification of areas which might merit more intensive sampling was also accomplished. The clusters of samples with high Hg concentrations in both areas may indicate high heat flow and should be investigated further. Problems involving the use of this method in the Cascades were also identified. Both areas north and south of the mountain had approximately the same standard deviation (expressed as a percentage of the mean), even though the sampling horizons seemed much more consistent and less disturbed in the Marble Mountain area than in the Green River Soda Springs area. This may indicate that for these areas, secondary controls are more important, or that Hg anomalies are much smaller than indicated in studies of other areas.

  16. Geologic Mapping of Isabella Quadrangle (V-50) and Helen Planitia, Venus

    NASA Technical Reports Server (NTRS)

    Bleamaster, Leslie F., III

    2008-01-01

    (25-50 S, 180-210 E) is host to numerous coronae and small volcanic centers (paterae and shield fields), focused (Aditi and Sirona Dorsa) and distributed (penetrative north-south trending wrinkle ridges) contractional deformation, and radial and linear extensional structures, all of which contribute materials to and/or deform the expansive surrounding plains (Nsomeka and Wawalag Planitiae). Regional plains, which are a northern extension of regional plains mapped in the Barrymore Quadrangle V-59 [1], dominate the V-50 quadrangle. Previous mapping divided the regional plains into two members: regional plains, members a and b [2]. A re-evaluation of these members has determined that a continuous and consistent unit contact does not exist; however, the majority of this radar unit or surficial unit will still be displayed on the final map as a stipple pattern as it is a prevalent feature of the quadrangle. With minimal tessera or highland material, much of the quadrangle s oldest materials are plains units (the regional plains). Much of these plains are covered with small shield edifices that exhibit a variety of material contributions (or flows). In the northwest, several flows emerge and flow to the southeast from Diana-Dali Chasmata. Local corona- and mons-fed flows superpose the regional plains; however, earlier stages of volcano-tectonic centers marked by arcuate and radial structural elements, including terrain so heavily deformed that it takes on a new appearance, may have developed prior to or concurrently with the region plains. Northtrending deformation belts disrupt the central portion of the map area and wrinkle ridges parallel these larger belts. Isabella crater, in the northeastern quadrant, is highly asymmetric and displays two prominent ejecta blanket morphologies, which generally correlate with distance from the impact structure suggesting that ejecta block size or ejecta blanket thickness may be the cause. The crater floor is very dark and shows no direct connection with the large outflow to the south, which emphasizes the asymmetry observed. Isabella crater ejecta and outflow materials clearly postdate several small craters in the vicinity.

  17. Who Can Be a Hero?: Helen Keller, Annie Sullivan, and Discovering Strength of Character

    ERIC Educational Resources Information Center

    Morin, Kathleen Dunlevy; Bernheim, Rachel Oestreicher

    2005-01-01

    "A Study of Heroes: Making a Difference Using Your Heart, Intellect, and Talents" is a program originally developed in diverse school communities. Students learn to distinguish between the concepts of hero and celebrity and to discover the real heroes in their own families, schools, communities, and most importantly--within themselves. This…

  18. Living Proof: What Helen Keller, Marilyn Monroe, and Marie Curie Have in Common.

    ERIC Educational Resources Information Center

    Saul, E. Wendy

    1986-01-01

    Examines biographies of Marie Curie written for children and discusses two types of distortions: simple misrepresentations of fact and selective retelling of the past. It is concluded that biographies of minority or female success should deal specifically with strategies used by the hero or heroine to combat prejudice. (EM)

  19. Arsenic stability and mobilization in soil at an amenity grassland overlying chemical waste (St. Helens, UK).

    PubMed

    Hartley, William; Dickinson, Nicholas M; Clemente, Rafael; French, Christopher; Piearce, Trevor G; Sparke, Shaun; Lepp, Nicholas W

    2009-03-01

    A 6.6 ha grassland, established on a former chemical waste site adjacent to a residential area, contains arsenic (As) in surface soil at concentrations 200 times higher than UK Soil Guideline Values. The site is not recognized as statutory contaminated land, partly on the assumption that mobility of the metalloid presents a negligible threat to human health, groundwater and ecological receptors. Evidence for this is evaluated, based on studies of the effect of organic (green waste compost) and inorganic (iron oxides, lime and phosphate) amendments on As fractionation, mobility, plant uptake and earthworm communities. Arsenic mobility in soil was low but significantly related to dissolved organic matter and phosphate, with immobilization associated with iron oxides. Plant uptake was low and there was little apparent impact on earthworms. The existing vegetation cover reduces re-entrainment of dust-blown particulates and pathways of As exposure via this route. Minimizing risks to receptors requires avoidance of soil exposure, and no compost or phosphate application.

  20. Plagioclase populations and zoning in dacite of the 2004-2005 Mount St. Helens eruption: constraints for magma origin and dynamics: Chapter 34 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

    USGS Publications Warehouse

    Streck, Martin J.; Broderick, Cindy A.; Thronber, Carl R.; Clynne, Michael A.; Pallister, John S.; Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

    2008-01-01

    We propose that crystals with no dissolution surfaces are those that were supplied last to the shallow reservoir, whereas plagioclase with increasingly more complex zoning patterns (that is, the number of zoned bands bounded by dissolution surfaces) result from prolonged residency and evolution in the reservoir. We propose that banding and An zoning across multiple bands are primarily a response to thermally induced fluctuations in crystallinity of the magma in combination with recharge; a lesser role is ascribed to cycling crystals through pressure gradients. Crystals without dissolution surfaces, in contrast, could have grown only in response to steady(?) decompression. Some heating-cooling cycles probably postdate the final eruption in 1986. They resulted from small recharge events that supplied new crystals that then experienced resorption-growth cycles. We suggest that magmatic events shortly prior to the current eruption, recorded in the outermost zones of plagioclase phenocrysts, began with the incorporation of acicular orthopyroxene, followed by last resorption, and concluded with crystallization of euhedral rims. Finally, we propose that 2004-5 dacite is composed mostly of dacite magma that remained after 1986 and underwent subsequent magmatic evolution but, more importantly, contains a component of new dacite from deeper in the magmatic system, which may have triggered the new eruption.

  1. Trace element and Pb isotope composition of plagioclase from dome samples from the 2004-2005 eruption of Mount St. Helens, Washington: Chapter 35 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

    USGS Publications Warehouse

    Kent, Adam J.R.; Rowe, Michael C.; Thornber, Carl R.; Pallister, John S.; Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

    2008-01-01

    Plagioclase crystals from gabbronorite inclusions in three dacite samples have markedly different trace-element and Pbisotope compositions from those of plagioclase phenocrysts, despite having a similar range of anorthite contents. Inclusions show some systematic differences from each other but typically have higher Ti, Ba, LREE, and Pb and lower Sr and have lower 208Pb/206Pb and 207Pb/206Pb ratios than coexisting plagioclase phenocrysts. The compositions of plagioclase from inclusions cannot be related to phenocryst compositions by any reasonable petrologic model. From this we suggest that they are unlikely to represent magmatic cumulates or restite inclusions but instead are samples of mafic Tertiary basement from beneath the volcano.

  2. 238U-230Th-226Ra disequilibria in dacite and plagioclase from the 2004-2005 eruption of Mount St. Helens: Chapter 36 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

    USGS Publications Warehouse

    Cooper, Kari M.; Donnelly, Carrie T.; Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

    2008-01-01

    230Th)/(232Th) measured for the 1980s reference suite. However, (230Th)/(232Th) for plagioclase separates for dome samples erupted during October and November 2004 are significantly different from corresponding whole-rock values, which suggests that a large fraction (>30 percent) of crystals in each sample are foreign to the host liquid. Furthermore, plagioclase in the two 2004 samples have U-series characteristics distinct from each other and from plagioclase in dacite erupted in 1982, indicating that (1) the current eruption must include a component of crystals (and potentially associated magma) that were not sampled by the 1980-86 eruption, and (2) dacite magmas erupted only a month apart in 2004 contain different populations of crystals, indicating that this foreign component is highly heterogeneous within the 2004-5 magma reservoir.

  3. The Pleistocene eruptive history of Mount St. Helens, Washington, from 300,000 to 12,800 years before present: Chapter 28 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

    USGS Publications Warehouse

    Clynne, Michael A.; Calvert, Andrew T.; Wolfe, Edward W.; Evarts, Russell C.; Fleck, Robert J.; Lanphere, Marvin A.; Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

    2008-01-01

    Preliminary petrographic analysis of these older rocks suggests that the volcano’s magmatic system was simpler during the Ape Canyon stage than during subsequent stages and that the magmatic system has evolved from relatively simple to more complex as the volcano matured. Compositional cycles as envisioned by C.A. Hopson and W.G. Melson for the Spirit Lake stage probably did not occur during the Ape Canyon stage but developed later during the Cougar and Swift Creek stages.

  4. Seismicity associated with renewed dome building at Mount St. Helens, 2004-2005: Chapter 2 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

    USGS Publications Warehouse

    Morgan, Seth C.; Malone, Stephen D.; Qamar, Anthony I.; Thelen, Weston A.; Wright, Amy K.; Caplan-Auerbach, Jacqueline; Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

    2008-01-01

    2.0-3.4) dominated seismic energy release. Over time there were significant variations in drumbeat size, spacing, and spectra that correlated with changes in the style of extrusion at the surface. Changes in drumbeat character did not correspond to variations in magma flux at the conduit, indicating that drumbeat size and spacing may be more a function of the mechanics of extrusion than of the extrusion rate.

  5. Chemistry, mineralogy, and petrology of amphibole in Mount St. Helens 2004-2006 dacite: Chapter 32 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

    USGS Publications Warehouse

    Thornber, Carl R.; Pallister, John S.; Lowers, Heather; Rowe, Michael C.; Mandeville, Charles W.; Meeker, Gregory P.; Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

    2008-01-01

    Decompression-related reaction rims around subhedral, rounded, resorbed, and fragmented amphibole phenocrysts, regardless of composition, indicate that this mixed-crystal assemblage was being broken, abraded, and dissolved in the magma as a result of mechanical mixing before and during early stages of ascent from conduit roots extending into a mushy cupola of the shallow reservoir. In the earliest lava samples (October 2004), amphiboles with <3-μm rims associated with a glassier matrix than later samples suggest a slightly faster ascent rate consistent with the relatively high eruptive flux of the earliest phases of dome extrusion. Reaction rim widths of ~5 μm on amphibole in all subsequently extruded lava result from a steady influx and upward transport of magma from 3.5-2.5-km to ~1-km depth at rates of ~600 to ~1,200 m/day, through a conduit less than 10 m in radius. Slower ascent rates inferred from volumetric-flux and matrixcrystallization parameters are explained by a widening of the conduit to greater than 60 m radius within 1 km of the surface.

  6. Chlorine degassing during the lava dome-building eruption of Mount St. Helens, 2004-2005: Chapter 27 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

    USGS Publications Warehouse

    Edmonds, Marie; McGee, Kenneth A.; Doukas, Michael P.; Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

    2008-01-01

    O is magmatic, and (or) (2) some Cl present as alkali chloride (NaCl and KCl) in the gas phase. The mean molar Cl/S is similar to gases measured at other silicic subductionzone volcanoes during effusive activity; this may be due to the influence of Cl in the vapor on S solubility in the melt, which produces a solubility maximum for S at vapor Cl/S ~1.

  7. Use of digital aerophotogrammetry to determine rates of lava dome growth, Mount St. Helens, Washington, 2004-2005: Chapter 8 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

    USGS Publications Warehouse

    Schilling, Steve P.; Thompson, Ren A.; Messerich, James A.; Iwatsubo, Eugene Y.; Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

    2008-01-01

    Successful application of aerophotogrammetry was possible during the critical earliest parts of the eruption because we had baseline data and photogrammetric infrastructure in place before the eruption began. The vertical aerial photographs, including the DEMs and calculations derived from them, were one of the most widely used data sets collected during the 2004-5 eruption, as evidenced in numerous contributions to this volume. These data were used to construct photogeologic maps, deformation vector fields, and profiles of the evolving dome and glacier. Extruded volumes and rates proved to be critical parameters to constrain models and hypotheses of eruption dynamics and thus helped to assess volcano hazards.

  8. Growth of the 2004-2006 lava-dome complex at Mount St. Helens, Washington: Chapter 9 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

    USGS Publications Warehouse

    Vallance, James W.; Schneider, David J.; Schilling, Steve P.; Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

    2008-01-01

    The chief near-surface controls on spine extrusion during 2004-6 have been vent location, relict topographic surfaces from the 1980s, and spine remnants emplaced previously during the present eruption. In contrast, glacier ice has had minimal influence on spine growth. Ice as thick as 150 m has prevented formation of marginal angle-of-repose talus fans but has not provided sufficient resistance to stop spine growth or slow it appreciably. Spines initially emerged along a relict south-facing slope as steep as 40° on the 1980s dome. The open space of the moat between that dome and the crater walls permitted initial southward migration of recumbent spines. An initial spine impinged on the opposing slopes of the crater and stopped; in contrast, recumbent whaleback spines of phase 3 impinged on opposing walls of the crater at oblique angles and rotated eastward before breaking up. Once spine remnants occupied all available open space to the south, spines thrust over previous remnants. Finally, with south and east portions of the moat filled, spine growth proceeded westward. Although Crater Glacier had only a small influence on the growing spines, spine growth affected the glacier dramatically, initially dividing it into two arms and then bulldozing it hundreds of meters, first east and then west, and heaping it more than 100 m higher than its original altitude.

  9. Magmatic conditions and processes in the storage zone of the 2004-2006 Mount St. Helens dacite: Chapter 31 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

    USGS Publications Warehouse

    Rutherford, Malcom J.; Devine, Joseph D.; Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

    2008-01-01

    O2 values of NNO +1 log unit. Magnetite compositions suggest that the 2004-6 magma was formed by mingling of magmas less than 5-8 weeks before eruption and that the magma last equilibrated within this temperature range. The amphibole phenocryst zoning involves approximately equal amounts of a pressure-sensitive Al-Tschermak molecular substitution and a temperature-sensitive edenite substitution in one cycle of growth. Hydrothermal experiments done on the natural dacite show that crystallization of the Fe- and Al-rich amphibole end member requires pressures of 200-300 MPa at temperatures of 900°C, conditions approaching the upper temperature limit of amphibole stability. The dacitic magma crystallizes the An68 plagioclase when the pressure drops to 200 MPa at 900°C. The magma must cool at this depth to produce a complete An68-An40 plagioclase zone and a Mg-rich layer on the amphiboles before the magma is cycled back to a high pressure, when a new layer of Fe-rich amphibole is acquired. The amphibole crystallizing in the dacite experiments at less than 200 MPa is lower in aluminum than any compositions in the natural cyclically zoned phenocrysts. The outer rim on some 2004-6 amphibole phenocrysts appears to have formed in the 100-200 MPa range, as do some phenocrysts in the May 1980 dacite pumice. Plagioclase rims of An35 in the 2004-6 magmas indicate that phenocryst growth continued until the pressure decreased to 130 MPa and that ascent was slow until this depth. Magma then entered the conduit for a relatively rapid ascent to the surface as indicated by the very thin (less than 5 μm) decompression-induced rims on the amphibole phenocrysts.

  10. Analysis of GPS-measured deformation associated with the 2004-2006 dome-building eruption of Mount St. Helens, Washington: Chapter 15 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

    USGS Publications Warehouse

    Lisowski, Michael; Dzurisin, Daniel; Denlinger, Roger P.; Iwatsubo, Eugene Y.; Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

    2008-01-01

    . The discrepancy between the estimated cavity-volume loss and the >83×106-m3 volume of the erupted dome can be explained, for the most part, by exsolution of gas in the stored magma and by minor input of new magma during the eruption.

  11. Hogg [Sawyer Hogg, Hogg-Priestley, Sawyer-Hogg-Priestley], Helen, née Battles (1905-93)

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    Astronomer, born in Lowell, MA, and planned a career as a chemist. However, a total eclipse of the Sun in 1925, as she said, `tied me to astronomy for life'. After meeting ANNIE CANNON of the Harvard College Observatory, she worked at Harvard with HARLOW SHAPLEY on star clusters. She moved to Victoria, British Columbia, and started an observing program with the 72 in telescope to study variabl...

  12. The initial giant umbrella cloud of the May 18th, 1980, explosive eruption of Mount St. Helens

    USGS Publications Warehouse

    Sparks, R.S.J.; Moore, J.G.; Rice, C.J.

    1986-01-01

    The initial eruption column of May 18th, 1980 reached nearly 30 km altitude and released 1017 joules of thermal energy into the atmosphere in only a few minutes. Ascent of the cloud resulted in forced intrusion of a giant umbrella-shaped cloud between altitudes of 10 and 20 km at radial horizontal velocities initially in excess of 50 m/s. The mushroom cloud expanded 15 km upwind, forming a stagnation point where the radial expansion velocity and wind velocity were equal. The cloud was initiated when the pyroclastic blast flow became buoyant. The flow reduced its density as it moved away from the volcano by decompression, by sedimentation, and by mixing with and heating the surrounding air. Observations indicate that much of the flow, covering an area of 600 km2, became buoyant within 1.5 minutes and abruptly ascended to form the giant cloud. Calculations are presented for the amount of air that must have been entrained into the flow to make it buoyant. Assuming an initial temperature of 450??C and a magmatic origin for the explosion, these calculations indicate that the flow became buoyant when its temperature was approximately 150??C and the flow consisted of a mixture of 3.25 ?? 1011 kg of pyroclasts and 5.0 ?? 1011 kg of air. If sedimentation is considered, these figures reduce to 1.1 ?? 1011 kg of pyroclasts and 1.0 ?? 1011 kg of air. ?? 1986.

  13. Cooling rate and thermal structure determined from progressive magnetization of the dacite dome at Mount St. Helens, Washington

    SciTech Connect

    Dzurisin, D. ); Denlinger, R.P. ); Rosenbaum, J.G. )

    1990-03-10

    The study suggests that the dome consists of a hot, nonmagnetized core surrounded by a cool magnetized carapace and flanking talus. Temporal changes in the magnetic anomaly indicate that the magnetized carapace thickened at an average rate of 0.03 {plus minus} 0.01 m/d from 1984 to 1986. Petrographic and rock magnetic properties of dome samples indicate that the dominant process responsible for these changes is magnetization of extensively oxidized rock at progressively deeper levels within the dome as the rock cools through its blocking temperature, rather than subsequent changes in magetization caused by further oxidation. Newly extruded material cools rapidly for a short period as heat is conducted outward in response to convective heat loss from its surface. The cooling rate gradually declines for several weeks, and thereafter the material cools at a relatively constant rate by convective heat loss from its interior along fractures that propagate inward. The rate of internal convective heat loss through fractures varies with rainfall, snowmelt, and large-scale fracturing during subsequent eruptive episodes. In accordance with a model for solidification of the 1959 lava lake at Kilauea Iki, Hawaii, the authors picture the dome's magnetized carapace as being a two-phase, porous, convective zone separated from the nonmagnetized core of the dome by a thin, single-phase conductive zone. As a consequence of the heat balance between the conductive and convective zones, the blocking-temperature isotherm migrates inward at a relatively constant rate. If the dome remains inactive, the time scale for its complete magnetization is estimated to be 18-36 years, a forecast which can be refined by shallow drilling into the dome and by continuing studies of its growing magnetic anomaly.

  14. Modeling studies on the formation of Hurricane Helene: the impact of GPS dropwindsondes from the NAMMA 2006 field campaign

    NASA Astrophysics Data System (ADS)

    Folmer, Michael J.; Pasken, Robert W.; Chiao, Sen; Dunion, Jason; Halverson, Jeffrey

    2016-04-01

    Numerical simulations, using the weather research and forecasting (WRF) model in concert with GPS dropwindsondes released during the NASA African Monsoon Multidisciplinary Analyses 2006 Field Campaign, were conducted to provide additional insight on SAL-TC interaction. Using NCEP Final analysis datasets to initialize the WRF, a sensitivity test was performed on the assimilated (i.e., observation nudging) GPS dropwindsondes to understand the effects of individual variables (i.e., moisture, temperature, and winds) on the simulation and determine the extent of improvement when compared to available observations. The results suggested that GPS dropwindsonde temperature data provided the most significant difference in the simulated storm organization, storm strength, and synoptic environment, but all of the variables assimilated at the same time give a more representative mesoscale and synoptic picture.

  15. Comparison of sediment transport formulas and computation of sediment discharges for the North Fork Toutle and Toutle rivers, near Mount St. Helens, Washington

    USGS Publications Warehouse

    Hammond, S.E.

    1989-01-01

    This preliminary report presents results of computations using twelve different sediment discharge formulas along with data from two data collection sites in the Toutle River basin. Output from six bed material discharge formulas and six bedload discharge formulas was considered. The results of the computations are presented graphically for comparison purposes only. In addition to output from the formulas, the results from suspended-sediment samples and several bedload measurements using a Helley-Smith type bedload sampler are presented. No interpretation of the output is provided. (USGS)

  16. Changes in the organic material in lakes in the blast zone of Mount St. Helens, Washington: Hydrologic effects of the eruptions

    NASA Astrophysics Data System (ADS)

    McKnight, D. M.; Klein, J. M.; Wissmar, R. C.

    Large quantities of organic material were introduced into the nearby surface waters, either as soil and plants incorporated into pyroclastic, mudflow, or debris-avalanche deposits, or as blowndown timber swept into lakes by the lateral blast of hot volcanic gases. The resulting major increases in the concentration of dissolved organic material were one of the most significant changes in the water chemistry of surface waters of the blast zone. Increases in dissolved organic material were correlated with dense bacterial populations, and large increases in the concentrations of dissolved manganese, iron, and sulfur. The majority of the dissolved organic material was higher molecular weight, yellow organic acids. Many of the specific organic compounds identifiable by gas chromatography-mass spectrometry were derived from the pyrolysis of plant and soil organic material. These changes are discussed in detail.

  17. The Helen Keller World Conference on Services to Deaf-Blind Persons (4th, Stockholm, Sweden, September 28-October 3, 1989).

    ERIC Educational Resources Information Center

    Association of the Swedish Deaf-Blind, Enskede (Sweden).

    The monograph comprises the proceedings of a 1989 international conference on services to the deaf blind, including conference papers as well as reports from eight nations. Introductory material includes the text of the "Declaration of the Basic Needs of Deaf-Blind Persons" adopted at the conference, the conference program, and a list of…

  18. Simulation of three lahars in the Mount St Helens area, Washington using a one-dimensional, unsteady-state streamflow model

    USGS Publications Warehouse

    Laenen, Antonius; Hansen, R.P.

    1988-01-01

    A one-dimensional, unsteady-state, open-channel model was used to analytically reproduce three lahar events. Factors contributing to the success of the modeling were: (1) the lahars were confined to a channel, (2) channel roughness was defined by field information, and (3) the volume of the flow remained relatively unchanged for the duration of the peak. Manning 's 'n ' values used in computing conveyance in the model were subject to the changing rheology of the debris flow and were calculated from field cross-section information (velocities used in these calculations were derived from super-elevation or run-up formulas). For the events modeled in this exercise, Manning 's 'n ' calculations ranged from 0.020 to 0.099. In all lahar simulations, the rheology of the flow changed in a downstream direction during the course of the event. Chen 's 'U ', the mudflow consistency index, changed approximately an order of magnitude for each event. The ' u ' values ranged from 5-2,260 kg/m for three events modeled. The empirical approach adopted in this paper is useful as a tool to help predict debris-flow behavior, but does not lead to understanding the physical processes of debris flows. (Author 's abstract)

  19. Women as Members of Communities. Third Grade Social Studies: Abigail Adams, Sarah Winnemucca, Helen Keller, Shirley Chisholm, March Fong Eu, [and] Carmen Delgado Votaw.

    ERIC Educational Resources Information Center

    National Women's History Project, Santa Rosa, CA.

    Part of the National Women's History Project funded to promote the study of women in history, this unit will help third grade students learn about women's contributions to U.S. society. Equity cannot be achieved until equality is expected and until the contributions of all women are understood and accepted as a simple matter of fact. The unit…

  20. 4. Historic American Buildings Survey W. N. Manning, Photographer, Feb. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. Historic American Buildings Survey W. N. Manning, Photographer, Feb. 2, 1934. ORIG.? - COTTAGE TO SIDE OF HELEN KELLER HOUSE. (OLD OFFICE?) - Helen Keller House, 300 West North Commons, Tuscumbia, Colbert County, AL

  1. 78 FR 76100 - Newspapers Used for Publication of Legal Notices for Pre-Decisional Administrative Review...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-16

    ... decisions Sisters District Ranger decisions The Bulletin, Bend, Oregon Fremont-Winema National Forests... decisions Mount Adams District Ranger decisions Mount St. Helens National Volcanic Monument...

  2. 77 FR 14804 - Advisory Council on Alzheimer's Research, Care, and Services; Request for Nominations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-13

    ... ``representative of a state public health department.'' Nominations should include the nominee's contact... Services, 200 Independence Avenue SW., Washington, DC 20201. FOR FURTHER INFORMATION CONTACT: Helen...

  3. [Volcanoes: A Compilation of Four Articles Appearing in Issues of "Instructor,""Science and Children," and "Science Teacher" Magazines in September 1980 and March 1981.

    ERIC Educational Resources Information Center

    San Mateo County Office of Education, Redwood City, CA. SMERC Information Center.

    This compilation of four journal articles (Instructor, September 1980; Science and Children, September 1980; and Science Teacher, September 1980 and March 1981) focuses on volcanoes, particularly Mount St. Helens in Oregon. The first article, "The Earth is Alive!" describes the eruptions of Mount St. Helens, provides basic information on…

  4. Studies of digital seismic data obtained in geothermal and volcanic regions. Progress report

    SciTech Connect

    Fehler, M.

    1982-08-10

    Progress is reported in the following research areas: (1) study of tremor waveforms recorded at Mount St. Helens during 1980; (2) study of seismicity recorded during 1981 at Mount St. Helens; and (3) the monitoring of seismicity accompanying hydrofracturing experiments carried out in the Jemez Mountains of New Mexico. (ACR)

  5. Conceptual design of 100-TW solid state laser system

    NASA Astrophysics Data System (ADS)

    McMordie, John A.

    1995-12-01

    Currently the main solid state laser facilities used for plasma physics research in the United Kingdom are the VULCAN laser at the Rutherford Appleton Laboratory and the HELEN facility at the Atomic Weapons Establishment. In the future it is proposed to replace HELEN with a new 100 TW facility to come on line early in the next century.

  6. Anthropology and Popular Culture: A Case Study.

    ERIC Educational Resources Information Center

    Estes, Jack

    The study of popular culture in the United States is an appropriate anthropological endeavor, as evidenced in a case study of the volcanic eruption of Mt. St. Helens in Oregon. By examining its popular arts, anthropologists gain understanding of the culture and its people. For example, an analysis of reactions to the Mt. St. Helens eruption…

  7. Cascades Volcano Observatory

    USGS Publications Warehouse

    Venezky, Dina Y.; Driedger, Carolyn; Pallister, John

    2008-01-01

    Washington's Mount St. Helens volcano reawakens explosively on October 1, 2004, after 18 years of quiescence. Scientists at the U.S. Geological Survey's Cascades Volcano Observatory (CVO) study and observe Mount St. Helens and other volcanoes of the Cascade Range in Washington, Oregon, and northern California that hold potential for future eruptions. CVO is one of five USGS Volcano Hazards Program observatories that monitor U.S. volcanoes for science and public safety. Learn more about Mount St. Helens and CVO at http://vulcan.wr.usgs.gov/.

  8. Computers, Invention, and the Power to Change Student Writing.

    ERIC Educational Resources Information Center

    Strickland, James

    1987-01-01

    Appraises the computer as a prewriting aid. Evaluates both the quality and quantity of ideas produced by various invention techniques and programs, and compares results of similar studies by Hugh Burns and Helen Schwartz. (NKA)

  9. Amery Ice Shelf

    Atmospheric Science Data Center

    2013-04-16

    ... funded by NASA and undertaken by the Scripps Institution of Oceanography and the Australian Antarctic Division. The Multi-angle Imaging ... Laboratory), and Helen A. Fricker (Scripps Institution of Oceanography). Other formats available at JPL Oct 6, ...

  10. Writing (with) Cixous.

    ERIC Educational Resources Information Center

    Juncker, Clara

    1988-01-01

    Claims that by being open to the French (feminist) theories of Julia Kristeva, Luce Irigaray, and Helene Cixous, teachers of composition, male and female, might actually engender new textual and pedagogical strategies within the field and beyond. (ARH)

  11. Volcanoes: Coming Up from Under.

    ERIC Educational Resources Information Center

    Science and Children, 1980

    1980-01-01

    Provides specific information about the eruption of Mt. St. Helens in March 1980. Also discusses how volcanoes are formed and how they are monitored. Words associated with volcanoes are listed and defined. (CS)

  12. Stoma Care Nurse of the Year: BJN AWARD RUNNER UP.

    PubMed

    Disley, Helen; Greening, Lyn; Clow, Tara; Harker, Gillian

    Gill Little, National Nurse Manager SecuriCare (Medical), entered Helen, Lyn, Tara and Gillian into the Stoma Care Nurse of the Year category. Here, she explains the reasons behind her nomination. PMID:26419814

  13. Poly 3D fault modeling scripts/data for permeability potential of Washington State geothermal prospects

    DOE Data Explorer

    Michael Swyer

    2015-02-05

    Matlab scripts/functions and data used to build Poly3D models and create permeability potential GIS layers for 1) Mount St Helen's, 2) Wind River Valley, and 3) Mount Baker geothermal prospect areas located in Washington state.

  14. Pain Management and the Amputee

    MedlinePlus

    ... into plain language by Helen Osborne, 2006 Health Literacy Consulting, www.healthliteracy.com By Partners Against Pain® ... to the amputees who have them. They are physical, not psychological or all in your head . There ...

  15. Center for Practical Bioethics

    MedlinePlus

    ... medical students and the general public. LEARN MORE Bioethics Interviews and Lectures Helen Emmott INTERVIEW LISTEN Kaith ... Conversation with Rosemary and Myra Join live-streamed bioethics discussions with Myra Christopher and Rosemary Flanigan on ...

  16. Mentoring for new graduates.

    PubMed

    Graham, Helen

    2016-10-01

    The School of Veterinary Medicine in Dublin (UCD) has introduced an alumni mentoring programme for new veterinary and veterinary nursing graduates. Helen Graham, clinical education support manager, explains how it works.

  17. Writing Like a Good Girl

    ERIC Educational Resources Information Center

    Sitler, Helen Collins

    2008-01-01

    In a montage of genres, Helen Collins Sitler illuminates the subtle yet powerful, often detrimental messages we send to girls that silence their public and private voices and diminish their opportunities to question and learn.

  18. Old Truths, New Children.

    ERIC Educational Resources Information Center

    Delattre, Edwin J.

    1993-01-01

    Suggests that the formation of habits is the basis of character and morality. Supports this suggestion with citations from Henry James and other writers, and with examples of intellectual diligence from the lives of Helen Keller and Anne Frank. (HTH)

  19. Confident living program for senior adults experiencing vision and hearing loss.

    PubMed

    Berry, Paige; Kelley-Bock, Mia; Rei, Christine

    2008-01-01

    Many people experience both vision and hearing losses as they age. The Confident Living Program was developed by Helen Keller National Center to address the unique psychosocial and educational needs of older adults living with dual-sensory impairments.

  20. Person-centred Teams: A Practical Guide to Delivering Personalisation through Effective Team-work Sanderson Helen and Lepkowsky Mary Beth Person-centred Teams: A Practical Guide to Delivering Personalisation through Effective Team-work 168pp £19.99 Jessica Kingsley 9781849054553 184905455X [Formula: see text].

    PubMed

    2014-10-30

    FIRMLY ROOTED in the positive psychology paradigm, this practical guide begins by describing the development of personal profiles for team members. It then takes the reader through the person-centred teams framework.

  1. Long Range Plan: Academic Years 1984/85 through 1988/89. Information Services: Center for Educational Resources: Helene Fuld Learning Resources Center, Learning Center; Library Information Services: Stamford/Greenwich Center for Higher Education; Media Services; University Library; WPKN AM-FM Radio Station.

    ERIC Educational Resources Information Center

    Hunt, Judith Lin

    Both Bridgeport University and the division of Information Services have undergone many changes in the past few years as the university has restructured its colleges, established the Metropolitan College for adult learners, introduced a core curriculum for undergraduates, and placed increasing emphasis on professional programs. Information…

  2. Seismological investigation of crack formation in hydraulic rock-fracturing experiments and in natural geothermal environments. Progress report, September 1, 1982-August 31, 1983

    SciTech Connect

    Aki, K.

    1983-09-01

    Progress is reported on the following: interpretation of seismic data from the recent activities in Long Valley, California; theoretical study on a source model for the long-period events and volcanic tremor observed at Mount St. Helens; calculation of synthetic seismograms for the tremor source model; analysis of the Easter Island tremor records; testing and application of the Gaussian beam synthetic method to observations at Mount St. Helens; and field testing and development of a high-temperature borehole seismograph.

  3. Advances(?) in mitigating volcano hazards in Latin America

    USGS Publications Warehouse

    Hall, M.L.

    1991-01-01

    The 1980's were incredible years for volcanology. As a consequence of the Mount St. Helens and other eruptions, major advances in our understanding of volcanic processes and eruption dynamics were made. the decade also witnessed the greatest death toll caused by volcanism since 1902. Following Mount St. Helens, awareness of volcano hazards increased throughout the world; however, in Latin America, subsequent events showed that much was still to be learned. 

  4. Dry tilt network at Mount Rainier, Washington

    USGS Publications Warehouse

    Dzurisin, Daniel; Johnson, Daniel J.; Symonds, R.B.

    1984-01-01

    In addition to its primary responsibility of monitoring active Mount St. Helens, the David A. Johnston Cascades Volcano Observatory (CVO) has been charged with obtaining baseline geodetic and geochemical information at each of the other potentially active Cascade volcanoes. Dry tilt and/or trilateration networks were established during 1975-82 at Mount Baker, Mount St. Helens, Mount Hood, Mount Shasta, Lassen Peak, Crater Lake, and Long Valley caldera; coverage was extended during September 1982 to include Mount Rainier.

  5. A stratospheric aerosol increase during 1981, observed by lidar over mid-Europe

    NASA Astrophysics Data System (ADS)

    Reiter, R.; Jaeger, H.; Carnuth, W.; Funk, W.

    1982-04-01

    Lidar observations of variations in the aerosol layer due to the eruptions of Mt. St. Helens and the volcano Alaid in the Kurile Islands are reported and compared. One year after the Mt. St. Helens activity the backscattering coefficient had reduced to within 10% of the values observed in the pre-eruption period. Observed peaks were found to be moving upward, eventually forming a broad aerosol layer at 15-17 km height in July, 1981. The Alaid plume moved west to east and was determined to be the cause of aerosol disturbances up to the 20 km level. Data is presented of the time variation of the aerosol quantities and the time variation of the space resolved integral backscattering. Additional data has shown that both the Mt. St. Helens and the Alaid eruptions caused only one-third the aerosol perturbations as the Fuego eruption of 1974.

  6. Telelearning Models: Expanding the Community College Community. Nine Case Studies Showing How Colleges, Alone or in Partnerships, Creatively Utilize New Delivery Systems to Reach a Variety of Student Clienteles. AACJC Issues Series No. 3.

    ERIC Educational Resources Information Center

    Zigerell, James, Ed.

    Each of the nine articles in this monograph demonstrates the use of a particular telecommunications technology, or a mixture of technologies and media at particular community colleges. Following an introduction by James Zigerell, the monograph presents (1) "Teleconferencing: The Homebound Project at Rio Salado College," by Helen Sprawls, which…

  7. TEFL/TESL Newsletter, Volume 4, Number 3.

    ERIC Educational Resources Information Center

    Australian Dept. of Education, Canberra. Language Teaching Branch.

    The following articles of interest to teachers of English as a second language (ESL) are included: (1) "Guided Writing in a High School" by Jean Brent; (2) "The Silent Way--Report on a Workshop" by Andrew Weiler; (3) "Multicultural Education: Report on an In-Service Day" by Helen Crain-Welsby; (4) "An ESL Perspective on a Child's Language" by…

  8. Valuing the Place of Young People with Learning Disabilities in the Arts

    ERIC Educational Resources Information Center

    Goddard, Jennifer

    2015-01-01

    Methodologies of embodied learning, radical pedagogies and applied drama offer a lens through which to investigate the empowerment of young people with learning disabilities in Northern Ireland, thus counteracting more traditional, disempowering methods. According to Helen Nicholson, the "participatory, dialogic and dialectic qualities as…

  9. Concepts & Procedures. [SITE 2001 Section].

    ERIC Educational Resources Information Center

    Bauder, Deborah Y., Ed.; Mullick, Rosemary, Ed.; Sarner, Ronald, Ed.

    This document contains the following papers on concepts and procedures from the SITE (Society for Information Technology & Teacher Education) 2001 conference: "Using School District Standards To Develop Thematic Lessons for Electronic Portfolios" (Cindy L. Anderson and others); "Using Adobe Acrobat for Electronic Portfolio Development" (Helen C.…

  10. How Sex Attitudes Develop

    ERIC Educational Resources Information Center

    Arnstein, Helene S.

    1976-01-01

    Excerpt from "The Roots of Love" (Helene S. Arnstein, 1975). Book is concerned with feelings that are part of child's developmental stages. Included in excerpt are: genital self-discovery, masturbation, discovery of sex differences, and birth fantasies. Stresses importance of parent's feelings which are communicated to child.

  11. RTI & DI (Response to Intervention & Differentiated Instruction)

    ERIC Educational Resources Information Center

    Hanson, Helene M.

    2014-01-01

    In today's diverse and inclusive classrooms, teachers face the challenge of delivering instruction that is effective and accessible to students with a wide range of needs, abilities, and learning styles. Newly updated for 2014, "RTI & DI: Response to Intervention & Differentiated Instruction," by Helene Hanson, shows teachers how…

  12. Byron: A Collection of Critical Essays. Twentieth Century Views Series.

    ERIC Educational Resources Information Center

    West, Paul, Ed.

    One of a series of works aimed at presenting contemporary critical opinion on major authors, this collection includes essays by G. Wilson Knight, Bernard Blackstone, Mario Praz, Paul West, Guy Steffan, F. R. Leavis, W. W. Robson, Helen Gardner, George M. Ridenour, Edmund Wilson, Gilbert Highet, Bertrand Russell, and John Wain--all dealing with the…

  13. The Literacy Equation: Competence = Capability? National Conference of the Australian Council for Adult Literacy Conference Papers (Queensland, Australia, November 7-9, 1996).

    ERIC Educational Resources Information Center

    Queensland Council for Adult Literacy, Red Hill (Australia).

    Papers from the 19th Adult Literacy Conference convened by the Australian Council for Adult Literacy include: "A Little to the Right on Writing" (Brendan Bartlett, Margaret Fletcher); "Deconstructing the 'Australian Language and Literacy Policy'" (Helen Beazley); "Comparing Content-Centered and Learner-Centered Approaches in School Mathematics:…

  14. Discipline-Based Art Education: Its Criticisms and Its Critics.

    ERIC Educational Resources Information Center

    Eisner, Elliot W.

    1988-01-01

    Discusses the criticisms of discipline-based art education published in the March 1988 issue of "Art Education." Responds to the arguments of Peter London, Helen Muth, Norma K. Pittard, and Karen Hamblen. States that art education would be better served if the energy devoted to criticism was directed toward constructive ends. (GEA)

  15. 77 FR 39508 - Notice of Inventory Completion: Field Museum of Natural History, Chicago, IL; Correction

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-03

    ... National Park Service Notice of Inventory Completion: Field Museum of Natural History, Chicago, IL... Museum of Natural History in Chicago, IL (Field Museum). The human remains and associated funerary... Helen Robbins, Repatriation Director, Field Museum of Natural History, 1400 South Lake Shore......

  16. Ecology for conserving our sirenians

    USGS Publications Warehouse

    Bonde, Robert K.

    2012-01-01

    Review of: Ecology and conservation of the sirenia: dugongs and manatees. Helene Marsh, Thomas J. O'Shea and John E. Reynolds III. Cambridge University Press, Cambridge, 2012, 521 pp, ISBN 978-0-521-88828-8, US$135 and 978-0-521-71643-7, US$65.

  17. An Initial Exploration of the Potential Contributions of French Feminist Theory to Interpersonal Communication.

    ERIC Educational Resources Information Center

    Heinz, Bettina

    More than a decade after the provocative writings of French feminist writers Julie Kristeva, Luce Irigaray, Helene Cixous, and Monique Wittig first appeared, the exploration of sexual and gender differences continues to draw controversy. Their work has been considered mostly in regard to literature, philosophy, and feminist theory, but their…

  18. The Year in Science.

    ERIC Educational Resources Information Center

    Discover, 1982

    1982-01-01

    Highlights scientific accomplishments in 1981. Focuses on space sciences, medicine, geology, chemistry, physics, zoology, paleontology, environmental problems, and genetics including such topics as the Space Shuttle, Mount St. Helen's endangered species, genetic engineering, and the scientists associated with these accomplishments. (JN)

  19. 76 FR 14685 - Notice of Meetings, Front Range Resource Advisory Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-17

    ... available at: http://www.blm.gov/rac/co/frrac/co_fr.htm . Dated: March 9, 2011. Helen M. Hankins, State... Bureau of Land Management Notice of Meetings, Front Range Resource Advisory Council AGENCY: Bureau of.... Department of the Interior, Bureau of Land Management (BLM) Front Range Resource Advisory Council (RAC),...

  20. 75 FR 34479 - Notice of Meetings, Front Range Resource Advisory Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-17

    ... also available at: http://www.blm.gov/rac/co/frrac/co_fr.htm . Helen M. Hankins, State Director... Bureau of Land Management Notice of Meetings, Front Range Resource Advisory Council AGENCY: Bureau of.... Department of the Interior, Bureau of Land Management (BLM) Front Range Resource Advisory Council (RAC),...

  1. Criticism and the Teaching of Literature.

    ERIC Educational Resources Information Center

    Miller, James E., Jr., Ed.

    1965-01-01

    Articles contained in this publication are (1) "Criticism in Teaching Literature" by Wayne Booth; (2) "Criticism and Literature: A Reply" (to Booth's article) by Frederick J. Hoffman; (3) "Criticism in Context" by Helen C. White; (4) "Formalist Criticism and Shakespeare" by Kester Svendsen; (5) "Grammar, History, and Criticism" by Kenneth S.…

  2. Anne S. Young: Professor and Variable Star Observer Extraordinaire

    NASA Astrophysics Data System (ADS)

    Bracher, Katherine

    2011-05-01

    Anne Sewell Young (1871-1961) was one of the eight original members of the AAVSO, to which she contributed more than 6500 observations over 33 years. She also taught astronomy for 37 years at Mount Holyoke College; among her students was Helen Sawyer Hogg. This paper will look at her life and career both at Mount Holyoke and with the AAVSO.

  3. 72. MISSISSIPPI, MONROE CO. MAP OF MONROE COUNTY, ca. 1925 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    72. MISSISSIPPI, MONROE CO. MAP OF MONROE COUNTY, ca. 1925 Broad side of map of Monroe Co., 'Compliments of Home Mortgage & Realty Co., Amory, Miss.' Orig. scale: ca. 1 in. to 2 mi. No date. Property of Helen (Mrs. Sam L.) Crawford, Hamilton, Ms. Sarcone Photography, Columbus, Ms., Sep 1978. - Bridges of the Upper Tombigbee River Valley, Columbus, Lowndes County, MS

  4. First Language Learning.

    ERIC Educational Resources Information Center

    Kallen, Jeffrey L., Ed.

    2001-01-01

    This collection of papers includes the following: "Preface: The Acquisition of Celtic Languages" (Jeffrey L. Kallen); "The Development of Finiteness in Early Welsh" (Robert D. Borsley and Bob Morris Jones); "Acquiring Subject and Object Relatives; Evidence from Irish" (Helen Goodluck, Eithne Guilfoyle, and Sile Harrington); "The Language…

  5. Viewing Volcanoes

    ERIC Educational Resources Information Center

    Wighting, Mervyn J.

    2005-01-01

    When Mount St. Helens threatened to erupt again in 2004, it grabbed headlines and captured the imagination of the country. Science classrooms nationwide used the event as an opportunity to make real-world connections to Earth science concepts introduced in the classroom. Thanks to modern technology, teachers no longer have to wait for the next…

  6. Volcanology.

    ERIC Educational Resources Information Center

    McClelland, Lindsay; Simkin, Tom

    1983-01-01

    Consequences of major and minor volcanic eruptions which took place during 1982 are discussed. These include lava flows, explosive activity, cloud production, and earthquakes of such volcanoes as Mount St. Helens, El-Chichon (Mexico), and Galunggung (Indonesia). Books, conferences, and publications focusing on volcanology are highlighted. (JN)

  7. Language at Work. Selected Papers from the Annual Meeting of the British Association for Applied Linguistics (University of Birmingham, England, September 1997). British Studies in Applied Linguistics 13.

    ERIC Educational Resources Information Center

    Hunston, Susan, Ed.

    Papers on the role of language in the work environment include: "Institutions, Writing and Talk in Environmental Discourse" (Greg Myers); "Negotiating Training: Shifting Participant Frameworks in the Workplace" (Kristina Bennert); "Relational Management in Chinese-British Business Meetings" (Helen Spencer-Oatey, Jianyu Xing); "A Pragmatic Approach…

  8. Struggle for the Soul: John Lawrence Childs

    ERIC Educational Resources Information Center

    Stallones, Jared

    2010-01-01

    John Lawrence Childs was born in Eau Claire, Wisconsin on January 11, 1889, the second child of John Nelson Childs and Helen Janette (Nettie) Smith. In childhood Childs absorbed the values of industry, democracy, and a traditional, but socially conscious, religion. Childs was a Methodist and an intensely private person not given to talking about…

  9. Foreign Language Learning, Today and Tomorrow: Essays in Honor of Emma M. Birkmaier.

    ERIC Educational Resources Information Center

    Arendt, Jermaine D., Ed.; And Others

    The following essays are included: (1) "Futurism in Foreign Language Learning" by Frank M. Grittner and Percy B. Fearing; (2) "Humanism in Learning Foreign Languages" by Samuel L. Lieberman; (3) "Objectives for New Programs: A Thematic Approach in Second Language Learning" by Helen L. Jorstad; (4) "Individualization of Foreign Language Learning"…

  10. American Association for Higher Education (AAHE) Bulletin, 1994-95.

    ERIC Educational Resources Information Center

    Marchese, Theodore J., Ed.

    1995-01-01

    The 10 issues of this organizational bulletin for the 1994/95 school year present articles, panel discussion, interviews, and essays on issues concerning the advancement of higher education. Some of the articles included are: an interview with American Association for Higher Education (AAHE) board chair Helen Astin; an article titled "Academic…

  11. Volcanic-hazards assessments; past, present, and future

    USGS Publications Warehouse

    Crandell, D.R.

    1991-01-01

    Worldwide interest in volcanic-hazards assessments was greatly stimulated by the 1980 eruption of Mount St. Helens, just 2 years after a hazards assessment of the volcano was published in U.S Geological Survey Bulletin 1383-C. Many climactic eruption on May 18, although the extent of the unprecedented and devastating lateral blast was not anticipated. 

  12. Sustaining Sustainability: The Pedagogical Drift of Art Research and Practice

    ERIC Educational Resources Information Center

    Garoian, Charles R.

    2012-01-01

    In this article, the philosophical theories of Gilles Deleuze and Felix Guattari are juxtaposed with the research and practice of environmental artists Helen Mayer Harrison and Newton Harrison in order to explore and examine correspondences between their respective ways of thinking and performing sustainability. The complex and contradictory…

  13. 73. MISSISSIPPI, MONROE CO. MAP OF MONROE CO., ca. 1925 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    73. MISSISSIPPI, MONROE CO. MAP OF MONROE CO., ca. 1925 Broadside map of Monroe Co., published by the Examiner Printing Co., Aberdeen, Ms. Original scale: ca. 1 in. to 2 mi. No date. Property of Helen (Mrs. Sam L.) Crawford, Hamilton, Ms. Sarcone Photograpy, Columbus, Ms., Sep 1978. - Bridges of the Upper Tombigbee River Valley, Columbus, Lowndes County, MS

  14. Marked Difference

    ERIC Educational Resources Information Center

    Lampela, Laurel

    2008-01-01

    Helen Cozza is a contemporary artist living in New Mexico who began working as a painter and moved into printmaking. Prevalent in her work is the use of the grid and the patterns created by weaving. The imagery is reminiscent of the environmental deterioration that Cozza observed in Buffalo and Cleveland where she lived for many years. Cozza knew…

  15. Major Topics of School Business Management.

    ERIC Educational Resources Information Center

    Clark, James E., Ed.; Hertz, Karl V., Ed.

    Thirteen articles on major topics facing school business officials in the 1980s are presented in this book. The titles and their authors are (1) "The Pursuit of Equity in Financing Public Education," by R. Craig Wood, Helene B. Jones, and William L. Riley; (2) "Facilities: Major Issues Ahead," by C. William Day; (3) "Cooperative Decision Making in…

  16. Potential for seepage erosion of landslide dam

    USGS Publications Warehouse

    Meyer, W.; Schuster, R.L.; Sabol, M.A.

    1994-01-01

    The failure potential of the debris-avalanche dam at Castle Lake near Mount St. Helens, Washington, by three processes of seepage erosion (1) Heave; (2) piping; and (3) internal erosion, is examined. Results indicated that the dam is stable against piping but potentially locally unstable against heave. -from Authors

  17. Best Not Forget Lesbian, Gay, Bisexual, and Transgender Themed Children's Literature: A Teacher's Reflections of a More Inclusive Multicultural Education and Literature Program

    ERIC Educational Resources Information Center

    Flores, Gabriel

    2016-01-01

    For many years, educational practitioners have been implementing multicultural literature about African-American, Asian, and Latino families. Teachers have also presented literature about great leaders, such as Martin Luther King Jr. and Helen Keller. However, the same cannot be said about literature depicting lesbian, gay, bisexual, and…

  18. Diversity and Women's Career Development: From Adolescence to Adulthood. Women's Mental Health and Development, Volume 2.

    ERIC Educational Resources Information Center

    Farmer, Helen S.

    This book presents a variety of perspectives on career development for women that grew from an extensive study of high school students in 1980 with follow-ups in 1990 and 1993. "Theoretical Overview: The Longitudinal Study" (Helen S. Farmer) outlines the social learning theoretical framework underlying the study and describes study procedures,…

  19. 76 FR 17471 - Air Tour Management Plan for Haleakala National Park, Maui, HI; Public Meeting/Notice of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-29

    ... Federal Aviation Administration Air Tour Management Plan for Haleakala National Park, Maui, HI; Public..., Kahului, HI 96732. Wednesday, April 13, 2011, 5 p.m.-7 p.m. Kula Community Center, 3690 Lower Kula Road, Kula, HI 96790. Thursday, April 14, 2011, 5 p.m.-7 p.m. Helene Community Center (Hana), 150 Keawa...

  20. The Makah Whale Hunt: A Social Studies Symposium in the Classroom

    ERIC Educational Resources Information Center

    Bornstein-Grove, Matthew; Hamel, Fred L.

    2013-01-01

    The conversation starts quickly as two students come together in a 10th grade social studies classroom, half-way through a role play activity a symposium begins. Both students are sporting "Hello, my name is…" stickers on their shirts, and each attempts to speak in character. One represents an anti-whaling activist. Helen stands holding…

  1. 78 FR 21151 - Boise White Paper, LLC, A Subsidiary of Boise Paper Holdings, LLC, Including On-Site Leased...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-09

    ... determination was published in the Federal Register on February 6, 2013 (78 FR 8590). Workers are engaged in... Employment and Training Administration Boise White Paper, LLC, A Subsidiary of Boise Paper Holdings, LLC... Electric, Mitech, and Anne Elisabeth Elsey, St. Helens, OR; Boise White Paper, LLC, A Subsidiary of...

  2. Child Health and Access to Medical Care

    ERIC Educational Resources Information Center

    Leininger, Lindsey; Levy, Helen

    2015-01-01

    It might seem strange to ask whether increasing access to medical care can improve children's health. Yet Lindsey Leininger and Helen Levy begin by pointing out that access to care plays a smaller role than we might think, and that many other factors, such as those discussed elsewhere in this issue, strongly influence children's health.…

  3. Australian Information Education in the 21st Century--The Synergy among Research, Teaching and Practice

    ERIC Educational Resources Information Center

    Nastasie, Daniela L.

    2012-01-01

    In 2011 a group of Australian Library and Information Science academics led by Prof. Helen Partridge conducted an investigation into the Australian Library and Information Science education in the 21st century. The project was funded by the Australian Learning and Teaching Council (ALTC) and the final report, titled "Re-conceptualising and…

  4. Family Supports for Families with a Disabled Member. Monograph No. 39.

    ERIC Educational Resources Information Center

    Lipsky, Dorothy Kerzner, Ed.; And Others

    Five articles address issues in family support systems for persons with disabilities. Peter Mittler, Hellie Mittler and Helen McConachie present a set of general principles designed to encourage the development of genuine partnerships between professionals and parents in "Working Together: Guidelines for Partnership between Professionals and…

  5. ACCUMULATION AND TISSUE DISPOSITION OF PARTICLE ASSOCIATED ELEMENTS IN THE RAT AFTER REPEATED INTRATRACHAEL ADMINISTRATION OF SOURCE PARTICLES

    EPA Science Inventory

    The goal of this study was to determine the fate of source particle tracer elements following repeated intratracheal instillation (IT) to rats. PM samples comprised Mt. St. Helens ash (MSH) with no water-soluble metals, and oil flyash emission PM (EPM) with water-leachable solubl...

  6. In the Service of Neglected People: Anna Julia Cooper, Ontology, and Education

    ERIC Educational Resources Information Center

    Bonnick, Lemah

    2007-01-01

    The most influential accounts of Anna Julia Cooper's work have tended to focus on the question of women's equality. In this respect Mary Helen Washington credits Cooper with providing an "embryonic feminist analysis" in the 1890s. The focus of the author is on her understanding of educational matters, which should be seen as a powerful…

  7. The Unexpected Journey: Renewing Our Commitment to Students through Educational Action Research

    ERIC Educational Resources Information Center

    Meyer, Helen; Hamilton, Bennyce; Kroeger, Steve; Stewart, Stephanie; Brydon-Miller, Mary

    2004-01-01

    This article presents four cases of journeys of discovery and renewal, and the unexpected learning that results from exploring our practice with others. The authors are three classroom teachers--Steve, Stephanie and Bennyce--all of whom took part in a year-long action research sequence and the two professors--Helen and Mary--who co-taught these…

  8. Office Design: A Study of Environment.

    ERIC Educational Resources Information Center

    Manning, Peter, Ed.

    Reporting upon a study of environment which was based on the design of office buildings and office space, the study forms part of a continuing program of environmental research sponsored by Pilkington Brothers Limited of St. Helens, England. In this report the word 'environment' is used in the sense of the sum of the physical and emotional…

  9. Bilingual Education through Music.

    ERIC Educational Resources Information Center

    Soy, Rosa H.

    The purpose of this project was to design a bilingual/bicultural kindergarten course of study based on the concepts of the Richards Education Through Music Method. This method is rooted in the Hungarian composer-educator Zoltan Kodaly's educational philosophy and was developed in the U.S. by Mary Helen Richards. This is a method of teaching all…

  10. Working To Learn: Transforming Learning in the Workplace.

    ERIC Educational Resources Information Center

    Evans, Karen, Ed.; Hodkinson, Phil, Ed.; Unwin, Lorna, Ed.

    This book contains 13 papers on transformations in the nature of work that affect the learning and skill requirements of jobs and individuals and ways those requirements can be met. The following papers are included: "The Significance of Workplace Learning for a 'Learning Society'" (Karen Evans, Helen Rainbird); "Learning Careers: Conceptualizing…

  11. Shakespeare, The Tragedies: A collection of Critical Essays. Twentieth Century Views Series.

    ERIC Educational Resources Information Center

    Harbage, Alfred, Ed.

    One of a series of works aimed at presenting contemporary critical opinion on major authors, this collection includes essays by Alfred Harbage, H. B. Charlton, Willard Farnham, H. T. Price, Donald A. Stauffer, Brents Stirling, Maynard Mack, Helen Gardner, C. S. Lewis, Alvin Kernan, Bernard Spivack, L. C. Knights, Francis Fergusson, G. Wilson…

  12. Proceedings of the National Deaf-Blind Educational/Rehabilitation Exchange.

    ERIC Educational Resources Information Center

    Southwestern Region Deaf-Blind Center, Sacramento, CA.

    The document contains seven papers from the National Deaf-Blind Educational/Rehabilitation Exchange involving parents, teachers, and rehabilitators of deaf blind persons. In the keynote address "The Challenge of Creating Rainbows," R. Kinney comments on the declaration of rights of the deaf blind person adpoted by the Helen Keller World Conference…

  13. Horses: An Introduction to Horses: Racing, Ranching, and Riding for Blind and Physically Handicapped Individuals.

    ERIC Educational Resources Information Center

    Cylke, Frank Kurt, Ed.

    This annotated bibliography of materials focuses on horses, racing, ranching, and riding. Two articles are presented in full. They are: "Diary of a Blind Horseman: Confidence Springs from a Horse Named Sun" (Richard Vice and Steve Stone) and "Young Rider: Her Horses Show the Way" (Helen Mason). Each article tells the true story of a blind person's…

  14. Abuses in Guardianship of the Elderly and Infirm: A National Disgrace. A Briefing by the Chairman of the Subcommittee on Health and Long-Term Care of the Select Committee on Aging. House of Representatives, One Hundredth Congress, First Session (September 25, 1987).

    ERIC Educational Resources Information Center

    Congress of the U.S., Washington, DC. House Select Committee on Aging.

    This document presents a briefing by Representative Claude Pepper on the abuses in guardianship of the elderly and infirm, and testimony from witnesses at the Congressional hearing called to examine the issue of guardianship abuse. The opening statement of Representative Pepper and a prepared statement of Representative Helen Delich Bentley are…

  15. Death Education for the Health Professional.

    ERIC Educational Resources Information Center

    Benoliel, Jeanne Quint, Ed.

    The perspectives of a number of health professionals based on their experiences in providing death education courses are presented in essays. In "Interdisciplinary Death Education in a Nursing School" (Helen L. Swain and Kathleen V. Cowles), the development of an undergraduate elective course in death, dying, and bereavement at the University of…

  16. In A World Set Apart: The Dalton Dynasty at King Alfred School, 1920-62.

    ERIC Educational Resources Information Center

    Brooks, Ron

    1998-01-01

    Explains that Helen Parkhurst's Dalton Laboratory Plan disappeared quickly in many British schools but remained for over 40 years in the King Alfred School in London (England). Explores the development of the Dalton Plan at King Alfred, why this educational innovation thrived at the school, and the causes for its disappearance. (CMK)

  17. To Teach Responsibility, Bring Back the Dalton Plan.

    ERIC Educational Resources Information Center

    Edwards, June

    1991-01-01

    The Dalton Plan, developed by Helen Parkhurst in the 1920s, completely restructured the secondary school day into subject labs, with students determining their daily schedules. Eschewing the usual bell-driven, factory worker model, this approach abolished traditional classrooms and homework and allowed students to select monthly contracts and…

  18. The Dalton School: The Transformation of a Progressive School. Volume 34 in American University Studies, Series XIV, Education.

    ERIC Educational Resources Information Center

    Semel, Susan F.

    The Dalton School, an independent, progressive school on the Upper East Side of Manhattan, was founded in 1919 by Helen Parkhurst. She established a child-centered school that attempted to incorporate the concept of a democratic community within the boundaries of an educational program. The school's innovative program became known as the Dalton…

  19. The Dalton Plan and the Loyal, Capable Intelligent Citizen.

    ERIC Educational Resources Information Center

    Lee, Lesley Fox

    2000-01-01

    Explores central features of implementing the Dalton Plan, a system of individualized instruction, in English schools. Provides historical information on Helen Parkhurst, the creator of the Dalton Plan. Explores the validity of claims that the Dalton Plan provided short-term educational and long-term social effects. (CMK)

  20. 78 FR 16505 - Office of the Assistant Secretary for Planning and Evaluation; Advisory Council on Alzheimer's...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-15

    ... Alzheimer's Research, Care, and Services AGENCY: Department of Health and Human Services, Office of the... nominations for a new, non-Federal member of the Advisory Council on Alzheimer's Research, Care, and Services...) 690-7996, helen.lamont@hhs.gov . SUPPLEMENTARY INFORMATION: The Advisory Council on...