Publications
Publications from the staff of the Geology, Minerals, Energy, and Geophysics Science Center
Filter Total Items: 2532
Revising supraglacial rock avalanche magnitudes and frequencies in Glacier Bay National Park, Alaska Revising supraglacial rock avalanche magnitudes and frequencies in Glacier Bay National Park, Alaska
The frequency of large supraglacial landslides (rock avalanches) occurring in glacial environments is thought to be increasing due to feedbacks with climate warming and permafrost degradation. However, it is difficult to (i) test this; (ii) establish cause–effect relationships; and (iii) determine associated lag-times, due to both temporal and spatial biases in detection rates. Here we...
Authors
William Smith, Stuart A. Dunning, Neil Ross, Jon Telling, Erin K. Bessette-Kirton, Dan H. Shugar, Jeffrey A. Coe, M. Geertsema
Paleomagnetically defined brief lifespans for two large shield volcanoes in the Cascades Arc Paleomagnetically defined brief lifespans for two large shield volcanoes in the Cascades Arc
Mafic to intermediate shield volcanoes with multi-cubic-kilometer eruptive volumes are common in the Cascades Volcanic Arc, but little is known about their eruptive histories as either singular or sustained episodes, or the total time required for their construction. Paleomagnetic data were collected from the lava flows of Ash Creek Butte (17 sites) and Crater Mountain (14 sites) in...
Authors
Anthony Francis Pivarunas, Dawnika L. Blatter, L.J. Patrick Muffler, Michael A. Clynne, Andrew T. Calvert, Lauren N Harrison, R.L. Christiansen
Magmatic record of changing Cordilleran plate-boundary conditions—Insights from Lu-Hf isotopes in the Mojave Desert Magmatic record of changing Cordilleran plate-boundary conditions—Insights from Lu-Hf isotopes in the Mojave Desert
Belts of Cordilleran arc plutons in the eastern part of the Mojave crustal province, inboard from the southwestern North American plate boundary, record major magmatic pulses at ca. 180–160 and 75 Ma and smaller pulses at ca. 100 and 20 Ma. This cyclic magmatism likely reflects evolving plate-margin processes. Zircon Lu-Hf isotopic characteristics and inherited zircons for different-age...
Authors
Keith A. Howard, S.E. Shaw, Charlotte M. Allen
Inferring geologic structure from gravity anomalies: Proceed with caution Inferring geologic structure from gravity anomalies: Proceed with caution
Characterization of key geologic structures within a study region, such as basin depths, fault offsets, and fault dip, are often derived from gravity data. Gravity modeling of such subsurface geologic structure generally assumes either homogeneous or spatially uncorrelated densities within modeled rock bodies and overlying sediments. This assumption allows modeling to focus on the shape...
Authors
Geoffrey Phelps
Signatures of high-latitude waves in observations of geomagnetic acceleration Signatures of high-latitude waves in observations of geomagnetic acceleration
Models for the second time-derivative of the geomagnetic field reveal prominent activity at high latitudes. Alternating patches of positive and negative geomagnetic acceleration propagate to the west at speeds that exceed nominal fluid velocities in the core. We show that waves are a viable interpretation of these observations. Magnetic Rossby waves produce a high-latitude response with...
Authors
Rodrigo Chi-Duran, Margaret Susan Avery, Bruce Buffett
The curious case of the old dog in the sand The curious case of the old dog in the sand
The discovery of a large fossil canid jawbone in Idaho gives clues to the region’s diverse, verdant past.
Authors
Kari A. Prassack, Laura Walkup
Effects of structure and volcanic stratigraphy on groundwater and surface water flow: Hat Creek basin, California, USA Effects of structure and volcanic stratigraphy on groundwater and surface water flow: Hat Creek basin, California, USA
Hydrogeologic systems in the southern Cascade Range in California (USA) develop in volcanic rocks where morphology, stratigraphy, extensional structures, and attendant basin geometry play a central role in groundwater flow paths, groundwater/surface-water interactions, and spring discharge locations. High-volume springs (greater than 3 m3/s) flow from basin-filling (
Authors
Marina Francesca Marcelli, Erick R. Burns, L.J. Patrick Muffler, Andrew J Meigs, Jennifer A. Curtis, Christian E. Torgersen
Geochemistry and fluxes of gases from hydrothermal features at Newberry Volcano, Oregon, USA Geochemistry and fluxes of gases from hydrothermal features at Newberry Volcano, Oregon, USA
We present the chemical and isotopic compositions of gases and fluxes of CO2 from the hydrothermal features of Newberry Volcano, a large composite volcano located in Oregon's Cascade Range with a summit caldera that hosts two lakes, Paulina and East Lakes. Gas samples were collected from 1982 to 2021 from Paulina Hot Springs (PHS) on the shore of Paulina Lake, East Lake Hot Springs (ELHS...
Authors
Jennifer L. Lewicki, William C. Evans, Steven E. Ingebritsen, Laura E. Clor, Peter J. Kelly, Sara Peek, Robert A. Jensen, Andrew G. Hunt
Waters divided: A history of alluvial fan research and a view of its future Waters divided: A history of alluvial fan research and a view of its future
Flows exiting confined valleys tend to deposit sediment in fan-shaped landforms. Where deposition is wholly or largely by the tractive forces of flowing water, these landforms are called alluvial fans. They are the product of the progressive division of water and sediment downfan, from slopes that may exceed 0.10 to distal slopes that may be below 0.01. Channel depths also tend to...
Authors
Jonathan D. Stock
Variation in carbon and nitrogen concentrations among peatland categories at the global scale Variation in carbon and nitrogen concentrations among peatland categories at the global scale
Peatlands account for 15 to 30% of the world’s soil carbon (C) stock and are important controls over global nitrogen (N) cycles. However, C and N concentrations are known to vary among peatlands contributing to the uncertainty of global C inventories, but there are few global studies that relate peatland classification to peat chemistry. We analyzed 436 peat cores sampled in 24 countries...
Authors
Shaun A. Watmough, Spencer Gilbert-Parkes, Nathan Basiliko, Louis J. Lamit, Erik A. Lilleskov, Roxanne Andersen, Jhon del Aguila-Pasquel, Rebekka E. Artz, Brian W. Benscoter, Werner Borken, Luca Bragazza, Stefani M. Brandt, Suzanna L. Brauer, Michael A. Carson, Xin Chen, Rodney A. Chimner, Bev R. Clarkson, Alexander R. Cobb, Andrea S. Enriquez, Jenny Farmer, Samantha P. Grover, Charles F. Harvey, Lorna I. Harris, Christina Hazard, Alison M. Hoyt, John Hribljan, Jyrki Jauhiainen, Sari Juutinen, Evan S. Kane, Klaus-Holger Knorr, Randy Kolka, Mari Kononen, Anna M. Laine, Tuula Larmola, Patrick A. Levasseur, Carmody K. McCalley, Jim McLaughlin, Tim R. Moore, Nadia Mykytczuk, Anna E. Normand, Virginia Rich, Bryce Robinson, Danielle L. Rupp, Jasmine Rutherford, Christopher W. Schadt, Dave S. Smith, Graeme Spiers, Leho Tedersoo, Pham Q. Thu, Carl C. Trettin, Eeva-Stiina Tuittila, Merritt Turetsky, Zuzana Urbanova, Ruth K. Varner, Mark P. Waldrop, Meng Wang, Zheng Wang, Matt Warren, Magdalena M. Wiedermann, Shanay T. Williams, Joseph B. Yavitt, Zhi-Guo Yu, Geoff Zahn
Exploring declustering methodology for addressing geothermal exploration bias Exploring declustering methodology for addressing geothermal exploration bias
Geothermal resources assessments use data that are unevenly distributed in space, with more data collected in areas with known thermal features. To meet the assumptions for geostatistical modeling (e.g., variography and kriging) such as having a random sample representative of the population, declustering may be needed to correct for spatial sample bias. Several declustering methods...
Authors
Cary Ruth Lindsey, Adam N. Price, Erick R. Burns
A modern multicentennial record of radiocarbon variability from an exactly dated bivalve chronology at the Tree Nob site (Alaska Coastal Current) A modern multicentennial record of radiocarbon variability from an exactly dated bivalve chronology at the Tree Nob site (Alaska Coastal Current)
Quantifying the marine radiocarbon reservoir effect, offsets (ΔR), and ΔR variability over time is critical to improving dating estimates of marine samples while also providing a proxy of water mass dynamics. In the northeastern Pacific, where no high-resolution time series of ΔR has yet been established, we sampled radiocarbon (14C) from exactly dated growth increments in a...
Authors
David C. Edge, Alan D. Wanamaker, Lydia M. Staisch, David J. Reynolds, Karine L. Holmes, Bryan A. Black