The Colombian emerald deposits are globally unique because they are hosted in hydrothermally altered black shales on either side of the Cordillera Oriental. We used electron microprobe analysis to study variations in trace element concentrations in transects across emeralds, and used the ⁴⁰Ar/³⁹Ar dating method to determine the age of...
Autonomous buoys were deployed in 2011 in the central Arctic: An Ice-Tethered Profiler (ITP) and Ice Mass Balance (IMB) buoys were deployed in the Makarov basin; a Polar Ocean Profiling System (POPS) and Ice Thickness (Ice-T) buoy were deployed on the Eurasian Basin. The two different sites were approximately 70km...
Marine sediment core OC1706B-02J ( 46° 15.4178 N, 125° 42.4543 W, at water depth 2263m), was collected on the lower continental slope near the base of the Willapa Canyon. It is a rapidly accumulating site (~30cm/kyr) located near the thrust front of the Cascadia Subduction Zone. The site is also...
Climate change is occurring at an increasingly rapid rate, with impacts heightened in the cold regions of the world including the Arctic. Warming effects are widespread, with one impacted process – freeze-thaw cycles – increasing in frequency and potentially triggering additional changes in permafrost soils that have previously acted as...
In recent decades, the occurrence of large, high severity wildfires has increased substantially in many parts of the world, including the western United States. These fires have the potential to impact water quality, aquatic ecosystems, and downstream communities for many decades. As such, it is increasingly important to understand the...
Nitrous oxide is an important greenhouse gas that has both natural and anthropogenic sources in the modern atmosphere (Ciais et al., 2013). This project expanded the knowledge of the history of atmospheric N2O in the geologic past by measuring N2O concentrations in air trapped in very old polar ice. A...
Drought represents an import part of natural hydrologic cycles that govern the rate and transportation of water on global and regional scales. (Trenberth, et al. 2015) Agriculturally, drought represents a threat to crop production and can endanger political and economic stability through the loss of resources and the threat of...
The dense Corvallis array deployed in January of 2022 aided in the high-resolution study of local geology. This array was made of 177 SmartSolo 3-component 5 Hz geophones around Corvallis, with a 93 geophone profile going west towards Bald Hill for approximately 5 km at an average of 64 m...
This study tested the utility of a variable mixing efficiency formulation proposed by Mashayek, et al. (2017) for use in oceanographic models other than the modern, pre-industrial ocean. This formulation is used to calculate diapycnal (vertical) mixing due to unresolved subgrid-scale processes. Results from Last Glacial Maximum (LGM) simulations for...
Freshwater flux from the Greenland Ice Sheet has the capacity to affect regional and global circulation as well as contribute to sea level rise. Outlet glaciers are an important part of this process. They provide pathways for inland glaciers and ice sheets to melt and drain into the surrounding oceans....