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Deep-Water Turbidites As Holocene Earthquake Proxies: The Cascadia Subduction Zone And Northern San Andreas Fault Systems, Chris Goldfinger, C. Hans Nelson, Joel E. Johnson
Deep-Water Turbidites As Holocene Earthquake Proxies: The Cascadia Subduction Zone And Northern San Andreas Fault Systems, Chris Goldfinger, C. Hans Nelson, Joel E. Johnson
Faculty Publications
New stratigraphic evidence from the Cascadia margin demonstrates that 13 earthquakes ruptured the margin from Vancouver Island to at least the California border following the catastrophic eruption of Mount Mazama. These 13 events have occurred with an average repeat time of ?? 600 years since the first post-Mazama event ?? 7500 years ago. The youngest event ?? 300 years ago probably coincides with widespread evidence of coastal subsidence and tsunami inundation in buried marshes along the Cascadia coast. We can extend the Holocene record to at least 9850 years, during which 18 events correlate along the same region. The pattern …
Analysis Of Vesicular Basalts And Lava Emplacement Processes For Application As A Paleobarometer/Paleoaltimeter: A Reply, Dork L. Sahagian, Alexander A. Prusevich, William D. Carlson
Analysis Of Vesicular Basalts And Lava Emplacement Processes For Application As A Paleobarometer/Paleoaltimeter: A Reply, Dork L. Sahagian, Alexander A. Prusevich, William D. Carlson
Faculty Publications
No abstract provided.
Production Of Methyl Bromide In A Temperate Forest Soil, Ruth K. Varner, Marguerite L. White, Cindy H. Mosedale, Patrick M. Crill
Production Of Methyl Bromide In A Temperate Forest Soil, Ruth K. Varner, Marguerite L. White, Cindy H. Mosedale, Patrick M. Crill
Faculty Publications
Field enclosure measurements of a temperate forest soil show net uptake of ambient methyl bromide (CH3Br), an important trace gas in both tropospheric and stratospheric ozone cycling. The net flux for 1999 was estimated to be −168 ± 72 μg CH3Br m−2 (negative indicates loss from the atmosphere). Individual enclosure flux measurements ranged from −4.0 to +3.3 μg CH3Br m−2 d−1. Soil consumption of CH3Br was estimated from laboratory soil incubations. Production of CH3Br was calculated as the difference between net flux and predicted consumption. Fungi could be responsible for the production of CH3Br in this temperate forest soil.
Experimentally Induced Root Mortality Increased Nitrous Oxide Emission From Tropical Forest Soils, Ruth K. Varner, Michael Keller, Jillan R. Robertson, Jadson D. Dias, Hudson Silva, Patrick M. Crill, Megan E. Mcgroddy, Whendee L. Silver
Experimentally Induced Root Mortality Increased Nitrous Oxide Emission From Tropical Forest Soils, Ruth K. Varner, Michael Keller, Jillan R. Robertson, Jadson D. Dias, Hudson Silva, Patrick M. Crill, Megan E. Mcgroddy, Whendee L. Silver
Faculty Publications
We conducted an experiment on sand and clay tropical forest soils to test the short‐term effect of root mortality on the soil‐atmosphere flux of nitrous oxide, nitric oxide, methane, and carbon dioxide. We induced root mortality by isolating blocks of land to 1 m using trenching and root exclusion screening. Gas fluxes were measured weekly for ten weeks following the trenching treatment. For nitrous oxide there was a highly significant increase in soil‐atmosphere flux over the ten weeks following treatment for trenched plots compared to control plots. N2O flux averaged 37.5 and 18.5 ng N cm−2 h−1 from clay trenched …
Factors Affecting Ammonium Uptake In Streams - An Inter-Biome Perspective, Jackson R. Webster, Patrick J. Mulholland, Jennifer L. Tanks, H. Maurice Valett, Walter K. Dodds, Bruce J. Peterson, William B. Bowden, Clifford N. Dahm, Stuart Findlay, Stanley V. Gregory, Nancy B. Grimm, Stephen K. Hamilton, Sherri L. Johnson, Eugenia Marti, William H. Mcdowell, Judy L. Meyer, Donna D. Morrall, Steven A. Thomas, Wilfred M. Wollheim
Factors Affecting Ammonium Uptake In Streams - An Inter-Biome Perspective, Jackson R. Webster, Patrick J. Mulholland, Jennifer L. Tanks, H. Maurice Valett, Walter K. Dodds, Bruce J. Peterson, William B. Bowden, Clifford N. Dahm, Stuart Findlay, Stanley V. Gregory, Nancy B. Grimm, Stephen K. Hamilton, Sherri L. Johnson, Eugenia Marti, William H. Mcdowell, Judy L. Meyer, Donna D. Morrall, Steven A. Thomas, Wilfred M. Wollheim
Faculty Publications
The Lotic Intersite Nitrogen experiment (LINX) was a coordinated study of the relationships between North American biomes and factors governing ammonium uptake in streams. Our objective was to relate inter-biome variability of ammonium uptake to physical, chemical and biological processes. 2. Data were collected from 11 streams ranging from arctic to tropical and from desert to rainforest. Measurements at each site included physical, hydraulic and chemical characteristics, biological parameters, whole-stream metabolism and ammonium uptake. Ammonium uptake was measured by injection of '5~-ammonium and downstream measurements of 15N-ammonium concentration. 3. We found no general, statistically significant relationships that explained the variability …