PASSCAL Experiments http://www.passcal.nmt.edu/rss/experiments en Mount St Helens aka iMUSH http://www.passcal.nmt.edu/scheduledetails/exptnumb/201406 A 70-element broadband array will be deployed for two years, in a 50-km-radius pattern surrounding the Mount St. Helens volcano. This array will be used for a variety of analyses, both of Earth structureand seismicity. The 10-15 km station spacing is designed to optimize imaging from the middle crust to slab, and to provide a substantial boost in our ability to detect small earthquakes and deep long-period earthquakes. P- and S-wave tomography using both earthquake and active sources will be applied to direct and Moho-reflected arrivals to image the volcano. Receiver functions analysis will reveal wavespeed discontinuities in the mid crust, Moho and subducting slab. Ambient Noise Tomography will provide constraints on the shear wavespeeds throughout the crust and upper most mantle. PALSIE http://www.passcal.nmt.edu/scheduledetails/exptnumb/201435 We will perform an active source experiment to determine the thickness of the active layer in support of a continuous passive experiment that is monitoring the thickness in real time. Mt St Helens http://www.passcal.nmt.edu/scheduledetails/exptnumb/201405 Seismic tomography experiment of the Mt St Helens volcanic system. Project consists of 2 orthogonal refraction profiles and 4 areal surveys to record 24 shots. Target goals are to illuminate the upper, middle, and lower crust of the Mt St Helens volcanic system. SEGMeNT http://www.passcal.nmt.edu/scheduledetails/exptnumb/201302 This experiment will acquire a family of geophysical, geochemical and geological observations in and around northern Lake Malawi to test fundamental hypotheses regarding continental rupture. Together, these data will allow us to characterize extensional deformation and magmatism at depth in the crust, mantle lithosphere and upper asthenosphere. These include seismic reflection data, onshore/offshore wide-angle seismic reflection/refraction data, passive seismic data (including body waves and surface waves), seismicity, long-period and wide-band MT data, continuous GPS data, InSAR data, and geochemical data. The IRIS PASSCAL component consists of 40 BB stations and 16 IP stations deployed for a period of 18 months. SEGMeNT http://www.passcal.nmt.edu/scheduledetails/exptnumb/201302 This experiment will acquire a family of geophysical, geochemical and geological observations in and around northern Lake Malawi to test fundamental hypotheses regarding continental rupture. Together, these data will allow us to characterize extensional deformation and magmatism at depth in the crust, mantle lithosphere and upper asthenosphere. These include seismic reflection data, onshore/offshore wide-angle seismic reflection/refraction data, passive seismic data (including body waves and surface waves), seismicity, long-period and wide-band MT data, continuous GPS data, InSAR data, and geochemical data. The IRIS PASSCAL component consists of 40 BB stations and 16 IP stations deployed for a period of 18 months. UOFG2014 http://www.passcal.nmt.edu/scheduledetails/exptnumb/201408 Field geophysics class. Purpose is to collect shallow reflection and refraction data over landslides in the Coast Range and active faults in central Oregon. MAGIC http://www.passcal.nmt.edu/scheduledetails/exptnumb/201404 The Mid-Atlantic Geophysical Integrative Collaboration (MAGIC) experiment aims to characterize lithospheric structure, mantle flow, and topographic evolution of the southeastern US continental margin from the Atlantic coast to the continental interior. Blood Falls http://www.passcal.nmt.edu/scheduledetails/exptnumb/201316 On Taylor Glacier, as part of a past study we discovered seasonal seismicity localized on the crevasse out of which the unique Blood Falls feature flows, accompanying ground penetrating radar suggests that this feature is underlain by a fault in the subglacial material. This new project is aimed at discovering the source for Blood Falls and its relation to the seismicity and subglacial fault. We request 3 broad band seismometers which will be deployed for just over 2 years (3 summers). We also request 3 temporary short period seismometers to deploy during the summer months while we are on site. These will provide better source locations. The broad band stations will be deployed in sediments or on rock (stable boulder or bedrock) depending on availability. Homestake 3D Array http://www.passcal.nmt.edu/scheduledetails/exptnumb/201416 This experiment involves deployment of 28 modern broadband instruments in a three-dimensional configuration in the deepest mine in North America. 5 stations will be located in surface vaults and 23 will be located within the mine at levels of 800, 2000, 4100, and 4850 feet. The array is 3D because the mine allows the sensor network fill a volume of the earth compared to normal arrays constrained to lie at the earth's surface. The experiment was designed to characterize seismic noise for advanced gravity wave detectors (LIGO) where underground observatories are being considered as a way to reduce self-gravitation noise. For geophysics this experiment will provide fundamental new data on seismic anisotropy (the rock at Homestake is strongly anisotropic schist) and the free-surface effect. Banda Arc http://www.passcal.nmt.edu/scheduledetails/exptnumb/201412 Eastern Indonesia is one of the least well understood geological domains of our planet, and yet the region provides a truly remarkable natural experiment for unraveling the complex dynamics of convergent tectonics. The recent, subduction-related collision of the Australian continental lithosphere with the active Banda arc effectively captures the initiation of convergence orogenesis and offers a rare glimpse into a process that has shaped Earth’s evolution over geologic time, as well as providing fresh insights into seismic hazards confronting the world’s fourth most populous country. A number of mysteries remain about the transition from subduction to arc-continental collision in the Banda arc, reflecting fundamental gaps in the general understanding of collisional tectonics.