The city of Christchurch was surprised in 2010 and 2011 by unknown fault segments in the Canterbury region. I will be examining aftershock waveforms in the Canterbury region to try to determine amounts of slip on specified fault segments by looking at small repeating earthquakes over time. These small repeating earthquakes can give insight into the evolution of fault stress after an earthquake.
This summer I will be in Boise, Idaho at Boise State University, using newly acquired geophysical data to characterize a geothermal system at Neal Hot Springs in eastern Oregon. This data will be used to map faults related to shallow geothermal fluid flow. As the geothermal plant is readied via injection tests this summer, injection-related seismicity will be monitored and compared to background values that have through the past 12 months. I will examine both pre and post injection periods and not any changes in local seismicity in the vicinity of the power plant. Additional seismometer stations may also be deployed to aide in constraining fluid flow pathways.
This summer I will be at the USGS’s Earthquake Science Center in Menlo Park, CA. Although I will be helping out with fieldwork throughout the summer for other projects (including a possible survey for geothermal energy in Nevada), my main project will focus on the San Gregorio Fault Zone where it comes onshore at Point Ano Nuevo, here in California. We will be doing a high resolution seismic imaging survey across the fault, in order to better understand and visualize the subsurface in the area. Then, through data processing, primarily with the ProMax program, we will interpret the resulting images of the subsurface to better understand the mechanisms and actual location of different strands of the fault zone. These images can also be used to assess the earthquake risk along the fault, as well as determine the location of the water table and groundwater sources in the area.
This summer I am working with ultra-low frequency electromagnetic (ULFEM) data collected from 5 different recording sites in the greater San Francisco Bay Area. I will first catalog all the previously recorded data from each of the sites, indicating periods of time when particular channels at the sites were and weren’t functioning or recording, when batteries have died and when any changes were made to the setup of the site; the ultimate goal of the log will be to determine when periods of “good” data and “bad” data occurred. Then I will look more specifically at the “good” data to pick out particular events that we are pretty certain were being recorded, like lightening strikes and solar storms. By getting good at identifying known events, we will have more success identifying any anomalies that may be precursors to earthquakes.
This summer my project aims to analyze what effects thick sediment layers in the central and eastern US may have on the quality of P and S receiver functions which I will calculate by using both water-level deconvolution and iterative deconvolution. I will be comparing the two receiver functions as well as two separate areas which will likely be the Realfoot Rift along the New Madrid Seismic zone and the Mid-Continent Rift.
This summer I'm based at Stanford, studying shear wave anisotropy in the Ruby Mountains in northeastern Nevada. The area, part of the Basin and Range region, is a metamorpic core complex and the goal of my analysis is to determine the structure of the subsurface, in particular mapping the Moho and determining whether there are multiple layers of anisotropy. The main method I will be using is a Matlab software program called SplitLab to identify and interpret SKS splitting times from teleseismic earthquakes observed over the past two years.
The general scope of my project this summer is to use seismograms to calculate the group velocity dispersion and then use the curves for tomography. This will let us look at structures in the crust and upper mantle either beneath Australia. I will be using data from earthquakes that occured on the land in Australia and were large enough to generate surface waves. That type of earthquake is not too common in Australia and as a result most maps of Australia created using tomography rely on data from earthquakes along the plate boundaries instead of earthquakes on the land. If I can gather enough data and create enough dispersion curves then we will be able to compare my results to other maps of Australia.
Many don't really associate the two fields of glaciology and seismology, but in actuality, glaciers produce 'icequakes' within the glacier. Seismic stations in the ice and surrounding bedrock at Yahtse Glacier in southeastern Alaska have collected seismic data that I will be using. This summer I will be targeting the upper glacier icequakes not associated with calving of glaciers. I will be locating the origin of these icequakes, determining how frequently they occur, and comparing the seismic data with geological and meteorological data in order to better understand glacier movement and the influence of the surrounding environment.
This summer I will be identifying and locating volcanic earthquakes in northern Chile. The volcanoes of greatest interest to my project are Isluga, Parinacota, and Guallatiri, but we also hope to discover activity at other volcanoes in the region. This is part of a larger project where a network of seismometers has been deployed at multiple locations in Bolivia and Chile in order to create a catalog of background seismicity at many Andes volcanoes that have not been extensively monitored in the past. At a later stage in the project, we will interpret the significance of the background seismicity and try to understand the relationship between the seismicity and other volcanic activity such as deformation, gas emissions or thermal anomalies.
For my internship this summer, I will be working with data from the Salton Seismic Imaging Project (SSIP) that was aquired in 2011. This entails the picking of first arrival travel times from several shots along a specific SSIP line in order to model and interpret geological structures through the use of velocity models. Also, I will be assisting in surveying seismometer sites for IDOR and the deployment of the seismometers in August.
The aim of my project is to get a comprehensive picture of the tectonic boundary that occurs at the Salmon River Suture Zone. Located in Idaho and a small portion of eastern Oregon, this zone is where the Precambrian North American craton meets accreted terranes that now make up the Blue Mountain region of Oregon. The goal of the IDOR project is to understand how the accretionary edge of the continental margin was formed and subsequently modified by magmatism and stresses. Geochemical studies on the area have found a sharp isotopic gradient (Sr, O) that corresponds with a feature called the Western Idaho Shear Zone or WISZ for short. Batholiths have been emplaced in this area over time. The project aims to get a picture of the structure of this complex area.
My research is focused on nonvolcanic tremors (NVT) along the North Anatolian Fault (NAF) in Turkey. Furthermore, I will be comparing the NAF to the San Andreas Fault because it has been studied much more extensively. For example, numerous studies have shown NVT occur along the SAF, sometimes in response to big earthquakes in other locations. I will be trying to correlate properties of the SAF with NAF in the hopes of gaining a better understanding of the processes occurring in this particular area of the world.