Jason is a Research Geologist with Geology, Minerals, Energy, and Geophysics Science Center. He received a Ph.D in Geological Sciences from University of AK Fairbanks, a BS in Geological Sciences and in Aquatic and Fisheries from University of Washington. Since joining the USGS in 2011 as a Mendenhall Research Fellow, he has continued to put his expertise as a paleoceanographer to work.
He is a research geologist in the Geology, Minerals, Energy, and Geophysics Science Center, stationed in Menlo Park, CA. Jason is trained to use geochemical proxies to reconstruct past ocean conditions. His primary interest is in how past climates affect ocean ecosystems in the North Pacific Ocean during the Holocene (past 11,700 years). He is currently contributing to different projects using geochemical and geophysical tools to reconstruct past ocean ecosystem productivity and environmental conditions using multiple processes from organic carbon, CaCO3, and biogenic silica concentrations; organic matter (C & N) stable isotope ratios; inorganic trace metal data; 3-D computerized tomography (CT) scanning; core-scanning XRF; to multivariate statistical analyses. In addition, he also uses a combination of radiocarbon dating, tephrochronology (the identification and dating of volcanic ash deposits), and varve counts to develop robust age-depth models in marine sediment cores.
Professional Experience
2014 - current: USGS Research Geologist
2011- 2014: USGS Mendenhall Research Fellow
2010 - 2011: Idaho State University Postdoctoral Scientist
Education and Certifications
Ph.D., Geological Sciences, Univ. of Alaska Fairbanks, 2009
B.S., Geological Sciences, Univ. of WA [with Distinction], 2004
B.S., Aquatic and Fisheries Sciences, Univ. of WA [with Distinction], 2004
Science and Products
Pacific Ocean Patterns, Processes, and Productivity (POP3): Impacts of ancient warming on marine ecosystems and western North America
Piston and gravity core data collected during USGS cruise 2019-642-FA offshore of south-central California in support of the Bureau of Ocean Energy Management (BOEM) California Deepwater Investigations and Groundtruthing (Cal DIG I) alternative energy pro
Donated ROV vibracore and sampling data collected during Monterey Bay Aquarium Research Institute cruises in 2019 offshore of south-central California
California deepwater investigations and groundtruthing (Cal DIG) I: Fault and shallow geohazard analysis offshore Morro Bay
The California Deepwater Investigations and Groundtruthing (Cal DIG) I project focuses on the potential seafloor hazards and impacts of alternative energy infrastructure in the outer continental shelf region offshore of south-central California. This is one of three reports covering a single study area located between Monterey and Point Conception, California in federal waters outside of the State
Aleutian Low variability for the last 7500 years and its relation to the Westerly Jet
An 11,300 yr record of paleoclimatology and paleoceanography of the central California coast in a gravity core from Pioneer Seamount
A new set of basaltic tephras from southeastern Alaska represent key stratigraphic markers for the late Pleistocene
Ice-sheet modulation of deglacial North American monsoon intensification
A North American Hydroclimate Synthesis (NAHS) of the Common Era
A Holocene record of ocean productivity and upwelling from the northern California continental slope
A global multiproxy database for temperature reconstructions of the Common Era
Data, age uncertainties and ocean δ18O under the spotlight for Ocean2k Phase 2
High-resolution climate of the past ∼7300 years of coastal northernmost California: Results from diatoms, silicoflagellates, and pollen
Interaction between climate, volcanism, and isostatic rebound in Southeast Alaska during the last deglaciation
Science and Products
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Pacific Ocean Patterns, Processes, and Productivity (POP3): Impacts of ancient warming on marine ecosystems and western North America
Projections for AD 2100 suggest warming of +1-4°C in the North Pacific Ocean, which will result in widespread transformations throughout the marine environment and western North America. Many of these changes are beyond the predictive capabilities of current climate models. To better address this future uncertainty, our team is developing a geological framework using past warm intervals as... - Data
Piston and gravity core data collected during USGS cruise 2019-642-FA offshore of south-central California in support of the Bureau of Ocean Energy Management (BOEM) California Deepwater Investigations and Groundtruthing (Cal DIG I) alternative energy pro
This data release includes photographs, multi-sensor core logger (MSCL), porewater analyses, and location and depth data from piston and gravity cores collected off the south-central California coast. This dataset is one of several collected as part of the Bureau of Ocean Energy Management (BOEM)-funded California Deepwater Investigations and Groundtruthing (Cal DIG I) project. The purpose of theDonated ROV vibracore and sampling data collected during Monterey Bay Aquarium Research Institute cruises in 2019 offshore of south-central California
This dataset includes photographs of vibracores that were collected by the Monterey Bay Aquarium Research Institute (MBARI) in February 2019 and November 2019 aboard the R/V Western Flyer using the remotely operated vehicle (ROV) Doc Ricketts. The collection of these cores was funded entirely by MBARI, and the cores have been donated to the U.S. Geological Survey (USGS). The cores were collected i - Publications
Filter Total Items: 23
California deepwater investigations and groundtruthing (Cal DIG) I: Fault and shallow geohazard analysis offshore Morro Bay
The California Deepwater Investigations and Groundtruthing (Cal DIG) I project focuses on the potential seafloor hazards and impacts of alternative energy infrastructure in the outer continental shelf region offshore of south-central California. This is one of three reports covering a single study area located between Monterey and Point Conception, California in federal waters outside of the State
Aleutian Low variability for the last 7500 years and its relation to the Westerly Jet
The Aleutian Low (AL) is one of the major atmospheric systems that determines environmental conditions during winter in the North Pacific Ocean, with impacts that affect the climates of both Asia and North America from mid- to high latitudes. However, the multi-centennial and longer scale behavior of the AL during the Holocene is not fully understood. In this study, AL variability since 7.5 ka wasAn 11,300 yr record of paleoclimatology and paleoceanography of the central California coast in a gravity core from Pioneer Seamount
Diatom, pollen, silicoflagellate, and biogenic opal analyses from a 155 cm-long gravity core from Pioneer Seamount, offshore Santa Cruz, California (PS1410-06 GC, latitude 37.3°N, longitude 123.4°W, water depth 2165 m) are compiled for the last ~11,300 years and compared with those of ODP 1019 and TN062-O550 from northern California. The relative abundance record of the subtropical diatom FragilarA new set of basaltic tephras from southeastern Alaska represent key stratigraphic markers for the late Pleistocene
An 8-cm-thick black basaltic tephra with nine discrete normally graded beds is present in cores from a lake on Baker Island in southeastern Alaska. The estimated age of the tephra is 13,492 ± 237 cal yr BP. Although similar in age to the MEd tephra from the adjacent Mt. Edgecumbe Volcanic Field, this tephra is geochemically distinct. Black basaltic tephras recovered from two additional sites in soIce-sheet modulation of deglacial North American monsoon intensification
The North American monsoon, the dominant source of rainfall for much of the arid US Southwest, remains one of the least understood monsoon systems. The late Pleistocene evolution of this monsoon is poorly constrained, largely because glacial changes in winter rainfall obscure summer monsoon signatures in many regional proxy records. Here, we develop deglacial records of monsoon strength from isotoA North American Hydroclimate Synthesis (NAHS) of the Common Era
This study presents a synthesis of century-scale hydroclimate variations in North America for the Common Era (last 2000 years) using new age models of previously published multiple proxy-based paleoclimate data. This North American Hydroclimate Synthesis (NAHS) examines regional hydroclimate patterns and related environmental indicators, including vegetation, lake water elevation, stream flow andByWater Resources, Climate Research and Development Program, Energy Resources Program, Groundwater and Streamflow Information Program, Mineral Resources Program, National Laboratories Program, Science and Decisions Center, Florence Bascom Geoscience Center, Geology, Minerals, Energy, and Geophysics Science Center, Geosciences and Environmental Change Science Center, St. Petersburg Coastal and Marine Science CenterA Holocene record of ocean productivity and upwelling from the northern California continental slope
The Holocene upwelling history of the northern California continental slope is examined using the high-resolution record of TN062-O550 (40.9°N, 124.6°W, 550 m water depth). This 7-m-long marine sediment core spans the last ∼7500 years, and we use it to test the hypothesis that marine productivity in the California Current System (CCS) driven by coastal upwelling has co-varied with Holocene millennA global multiproxy database for temperature reconstructions of the Common Era
Reproducible climate reconstructions of the Common Era (1 CE to present) are key to placing industrial-era warming into the context of natural climatic variability. Here we present a community-sourced database of temperature-sensitive proxy records from the PAGES2k initiative. The database gathers 692 records from 648 locations, including all continental regions and major ocean basins. The recordsData, age uncertainties and ocean δ18O under the spotlight for Ocean2k Phase 2
The oceans make up 71% of the Earth’s surface area and are a major component of the global climate system. They are the world’s primary heat reservoir, and knowledge of the global ocean response to past and present radiative forcing is important for understanding climate change. PAGES’ Ocean2k working group aims to place marine climate of the past century within the context of the previous 2000 yeHigh-resolution climate of the past ∼7300 years of coastal northernmost California: Results from diatoms, silicoflagellates, and pollen
Piston core TN062-O550, collected about 33 km offshore of Eureka, California, contains a high-resolution record of the climate and oceanography of coastal northernmost California during the past ∼7.34 kyr. Chronology established by nine AMS ages on a combination of planktic foraminifers, bivalve shell fragments, and wood yields a mean sedimentation rate of 103 cm kyr−1. Marine proxies (diatoms andInteraction between climate, volcanism, and isostatic rebound in Southeast Alaska during the last deglaciation
Observations of enhanced volcanic frequency during the last deglaciation have led to the hypothesis that ice unloading in glaciated volcanic terrains can promote volcanism through decompression melting in the shallow mantle or a reduction in crustal magma storage time. However, a direct link between regional climate change, isostatic adjustment, and the initiation of volcanism remains to be demons - News
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