Publications
Filter Total Items: 2674
Simultaneous Middle Pleistocene eruption of three widespread tholeiitic basalts in northern California (USA): Insights into crustal magma transport in an actively extending back arc
Mapping and chronology are central to understanding spatiotemporal volcanic trends in diverse tectonic settings. The Cascades back arc in northern California (USA) hosts abundant lava flows and normal faults, but tholeiitic basalts older than 200 ka are difficult to discriminate by classic mapping methods. Paleomagnetism and chemistry offer independent means of correlating basalts, including the T
Authors
Drew T. Downs, Duane E. Champion, L. J. Patrick Muffler, Robert L. Christiansen, Michael A. Clynne, Andrew T. Calvert
Evolution of faulting induced by deep fluid injection, Paradox Valley, Colorado
High‐pressure fluid injection into a subhorizontal confined aquifer at 4.3–4.6 km depth induced >7000>7000 earthquakes between 1991 and 2012 within once seismically quiescent Paradox Valley in Colorado, with magnitudes up to MwMw 3.9. Earthquake hypocenters expanded laterally away from the well with time, defining the margins of the aquifer pressurized by injection at the well. Within 5 km of the
Authors
Roger P. Denlinger, Daniel R. H. O'Connell
The remarkable volcanism of Shastina, a stratocone segment of Mount Shasta, California
Mount Shasta, a 400 km3 volcano in northern California (United States), is the most voluminous stratocone of the Cascade arc. Most Mount Shasta lavas vented at or near the present summit; relatively smaller volumes erupted from scattered vents on the volcano’s flanks. An apron of pyroclastic and debris flows surrounds it.Shastina, a large and distinct cone on the west side of Mount Shasta, represe
Authors
Robert L. Christiansen, Andrew T. Calvert, Duane E. Champion, Cynthia A. Gardner, Judith E. Fierstein, Jorge A. Vazquez
Generalized models to estimate carbon and nitrogen stocks of organic soil horizons in Interior Alaska
Boreal ecosystems comprise one tenth of the world’s land surface and contain over 20 % of the global soil carbon (C) stocks. Boreal soils are unique in that its mineral soil is covered by what can be quite thick layers of organic soil. These organic soil layers, or horizons, can differ in their state of decomposition, source vegetation, and disturbance history. These differences result in varying
Authors
Kristen L. Manies, Mark Waldrop, Jennifer W. Harden
Latest Pleistocene to present geology of Mount Baker Volcano, northern Cascade Range, Washington
Mount Baker is the prominent andesitic stratocone that forms the youngest volcanic center in the Mount Baker volcanic field. Its heavily glaciated cone, rising to 3,286 meters, is an international landmark, dominating the skyline of Vancouver, British Columbia, even though the volcano is located 25 kilometers south of the international border. Mount Baker caught the attention of scientists and the
Authors
Kevin M. Scott, David S. Tucker, Jon L. Riedel, Cynthia A. Gardner, John P. McGeehin
Observations of an extreme atmospheric river storm with a diverse sensor network
Observational networks enhance real‐time situational awareness for emergency and water resource management during extreme weather events. We present examples of how a diverse, multitiered observational network in California provided insights into hydrometeorological processes and impacts during a 3‐day atmospheric river storm centered on 14 February 2019. This network, which has been developed ove
Authors
Benjamin J. Hatchett, Q. Cao, Phillip B. Dawson, C. J. Ellis, C. W. Hecht, B. Kawzenuk, J. T. Lancaster, T. C. Osborne, A. M. Wilson, M. L. Anderson, M. D. Dettinger, J. F. Kalansky, M. L. Kaplan, D. P. Lettenmaier, N. S. Oakley, R. M. Ralph, D. W. Reynolds, A. B. White, M. Sierks, E. Sumargo
Caldera collapse geometry revealed by near‐field GPS displacements at Kilauea Volcano in 2018
We employ near‐field GPS data to determine the subsurface geometry of a collapsing caldera during the 2018 Kīlauea eruption. Collapse occurred in 62 discrete events, with “inflationary” deformation external to the collapse, similar to previous basaltic collapses. We take advantage of GPS data from the collapsing block and independent constraints on the magma chamber geometry from inversion of defl
Authors
Paul Segall, Kyle R. Anderson, Fabio Pulvirenti, Taiyi Wang, Ingrid Johanson
Time-evolving surface and subsurface signatures of Quaternary volcanism in the Cascades arc
Increased resolution of data constraining topography and crustal structures provides new quantitative ways to assess province-scale surface-subsurface connections beneath volcanoes. We used a database of mapped vents to extract edifices with known epoch ages from digital elevation models (DEMs) in the Cascades arc (western North America), deriving volumes that likely represent ∼50% of total Quater
Authors
Daniel O'Hara, Leif Karlstrom, David W. Ramsey
Dating silica sinter (geyserite): A cautionary tale
We describe a new effort to date hydrothermal silica sinter deposits (geyserite) from the Upper Geyser Basin of Yellowstone National Park using 14C of co-deposited organic matter, U-series and cosmogenic 10Be methods. A majority of the samples were collected from stratigraphic sections, mainly at Riverside, Giant, and Castle Geysers. Ages obtained from 41 14C analyses range from modern to 12.1 cal
Authors
Dakota M. Churchill, Michael Manga, Shaul Hurwitz, Sara Peek, Joseph Licciardi, James B. Paces
Combining ash analyses with remote sensing to identify juvenile magma involvement and fragmentation mechanisms during the 2018/19 small eruption of Peteroa volcano (Southern Andes)
The Planchón Peteroa Volcanic Complex (PPVC) is located on the border of Chile and Argentina, and is one of the most active volcanic systems in the Andes. Holocene activity has included magma-water interaction with an evolving series of crater lakes, mainly sourced from Peteroa volcano. This study examines data from the 2018/19 eruption, together with the volcanic history of the PPVC, to elucidate
Authors
Jorge E Romero, Felipe Aguilera, Francisco Delgado, Danny Guzmán, Alexa R. Van Eaton, Nicolás Luengo, Javiera Caro, Jorge Bustillos, Alicia Guevara, Sven Holbik, Daniel Tormey, Iver Zegarra
Interpreting and reporting 40Ar/39Ar geochronologic data
The 40Ar/39Ar dating method is among the most versatile of geochronometers, having the potential to date a broad variety of K-bearing materials spanning from the time of Earth’s formation into the historical realm. Measurements using modern noble-gas mass spectrometers are now producing 40Ar/39Ar dates with analytical uncertainties of ∼0.1%, thereby providing precise time constraints for a wide ra
Authors
Allen J. Schaen, Brian R. Jicha, Kip V. Hodges, Pieter Vermeesch, Mark E. Stelten, Cameron M. Mercer, David Phillips, Tiffany Rivera, Fred Jourdan, Erin L. Matchan, Sidney R. Hemming, Leah E. Morgan, Simon P. Kelley, William S. Cassata, Matt T. Heizler, Paulo M. Vasconcelos, Jeff A. Benowitz, Anthony A.P. Koppers, Darren F. Mark, Elizabeth M. Niespolo, Courtney J. Sprain, William E. Hames, Klaudia F. Kuiper, Brent D. Turrin, Paul R. Renne, Jake Ross, Sebastian Nomade, Hervé Guillou, Laura E. Webb, Barbara A. Cohen, Andrew T. Calvert, Nancy Joyce, Morgan Ganderød, Jan Wijbrans, Osamu Ishizuka, Huaiyu He, Adán Ramirez, Jörg Pfänder, Margarita Lopez-Martínez, Huaning Qiu, Brad S. Singer
Response: Commentary: Variability in Shelf Sedimentation in Response to Fluvial Sediment Supply and Coastal Erosion Over the Past 1,000 Years in Monterey Bay, CA, United States
No abstract available.
Authors
Joe Carlin, Jason A. Addison, Amy Wagner, Valerie Evelyn Schwartz, Jamie Hayward, Victoria Severin