The ion implantation process is a very precise, controllable, and
reproducible method used to enhance material properties of finished
components such as ball bearings. Essentially, the target material is
bombarded by accelerated ions to form a thin alloyed layer in the
substrate. As the ions deposit their kinetic energy in...
Explosively erupting volcanoes and megathrust earthquakes (Mw 8+ magnitude) occur at subduction zones and adjacent volcanic arcs. Volcanic eruptions are observed occurring close in time to megathrust earthquakes in the historical record from at least the 18th century CE to present in locations globally, including Japan in 1707 CE (Chesley...
Volcanic and sedimentary deposits of the Mount Jefferson area (MJA) record a fourmillion-year history of arc-related volcanism related to the subduction of the Juan de Fuca plate beneath North America. 171 mapped stratigraphic units over an area of 150 km² reveal four periods of volcanic activity resulting in diverse composition...
Silicic caldera-forming eruptions are some of the largest and most destructive volcanic eruptions known, and present significant local and global hazards. The underlying processes within crustal magma plumbing systems that lead to the accumulation and eruption of large volumes of evolved magma remain enigmatic, yet there is broad consensus that...
During volcanic eruptions ascending magma undergoes decompression, resulting in a decrease of dissolved H2O. This creates unstable conditions for the hydrous mineral amphibole. As a result a reaction rim forms from anhydrous minerals such as pyroxene, plagioclase, and Fe-Ti oxides (Rutherford and Hill, 1993). There have been numerous studies done...
Diseases caused by parasites are recognized as significant sources of mortality in wild fish populations. I assessed the impacts of multispecies parasitism on a threatened stock of juvenile coho salmon (Oncorhynchus kisutch). A crucial prerequisite to this research was proper identification of parasites, which can be difficult for species lacking...
:
_____________________________________________________________________
Michael L. Kent
Diseases caused by parasites are recognized as significant sources of
The Early Oligocene Oregon Coast Range Intrusions (OCRI) consist of gabbroic rocks and lesser alkalic intrusive bodies that were emplaced in marine sedimentary units and volcanic sequences within a Tertiary Cascadia forearc basin. The alkalic intrusions include nepheline syenite, camptonite, and alkaline basalt. The gabbros occur as dikes and differentiated...
Semi-volatile trace metals (e.g., Cd, Sn, Pb, Zn, Cu, Mo) have been analyzed by using laser ablation ICP-MS in a number of silicate glasses (GSE-1G, GSD-1G, NIST 610, NIST 612, BCR-2G, BHVO-2G). Our work investigates and highlights sources of uncertainty in the analysis of semi-volatile metals using LA-ICP-MS. We identify...
Opakapaka (Pristipomoides filamentosus) is a snapper (family Lutjanidae) native to the waters around Hawaii. Recent population declines of this commercially important species have increased interest in the culture of this fish. Survival of this fish through the larval period in culture has been consistently low, usually not exceeding 2%. The...
The Tam McArthur Rim is a volcanic center located within the Tumalo Volcanic Field (TVF), approximately 25 km west of Bend, OR. The rim comprises of shallowly dipping bedded sequences of intermediate and silicic flows with minor tephra interbedding capped by a rhyodacite dome. Glacial activity has exposed significant portions...