PASSCAL Experiments http://www.passcal.nmt.edu/rss/experiments en AAA (triple A) http://www.passcal.nmt.edu/scheduledetails/exptnumb/201502 Four mini seismic arrays will be installed in Unalaska Island. They will image a variety of seismic events from the subduction zone including tremor, low frequency earthquakes associated with slow earthquakes and regular fast earthquakes. They will also capture events from nearby volcanoes (Makushin and Akutan) allowing us to better understand the volcanic plumbing systems. The arrays are designed to simultaneously image both subduction and volcanic system. Cascadia Initiative http://www.passcal.nmt.edu/scheduledetails/exptnumb/201430 This deployment of approximately 15 broadband instruments is to complement the focused OBS array of the Cascadia Initiative. Beginning in July 2014, 20 OBS will be deployed offshore this region with approximate station spacing of 10-15 km. We want to record on land with a comparable station spacing for as long as possible during the 12-15 month OBS deployment. Pacaya1314 http://www.passcal.nmt.edu/scheduledetails/exptnumb/201417 Our goal is do generate a set of recordings for a dense network of stations to study structure and source processes of strombolian eruption activity, tremor, and long-period earthquakes at Pacaya volcano. Because installing and maintaining 80 stations is extremely challenging, we will record at 80 sites using 20 stations and moving a subset each day in a manner we have had success with elsewhere. For repetitive events, we will combine recordings at all sites for dense, 80-station records. 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. Cascadia Initiative http://www.passcal.nmt.edu/scheduledetails/exptnumb/201430 This deployment of approximately 15 broadband instruments is to complement the focused OBS array of the Cascadia Initiative. Beginning in July 2014, 20 OBS will be deployed offshore this region with approximate station spacing of 10-15 km. We want to record on land with a comparable station spacing for as long as possible during the 12-15 month OBS deployment. 2014 IAS http://www.passcal.nmt.edu/scheduledetails/exptnumb/201411 Description:Imaging the Socorro Fault. POLENET2 backbone http://www.passcal.nmt.edu/scheduledetails/exptnumb/201337 We propose to continue and expand GPS and seismic studies in the ANET-POLENET Phae 2 project in order to advance understanding of geodynamic processes and their influence on the West Antarctic Ice Sheet. The work will, include the continental West Antarctic Rift System (WARS) and its shoulder along the Transantarctic margin of East Antarctica. In partnership with UK colleagues, we propose a new high-resolution crustal and mantle seismic transect that traverses the deepest subglacial basins, including the glacio-dynamically critical Pine Island and Thwaites Glacier regions. Crust and mantle structure of the deepest WARS basins and the Ellsworth-Whitmore mountains crustal block will be resolved by this transect. A nominal plan to reduce ANET by approximately half to a longer-term community 'backbone network' in the final 2 years of this project is presented, contingent on future funding. Note: this instrument request applies to the continuation of the POLENET backbone sites, including 8 seismographs that were previously deployed for the AGAP project on the polar plateau. 32 of the 34 systems in this request are already in the Antarctica, 2 additional backbone systems are requested for the new proposal time period. Ross Ice Shelf (RIS) http://www.passcal.nmt.edu/scheduledetails/exptnumb/201425 We will deploy 18 autonomous broadband seismographs provided by the IRIS PASSCAL program for two continuous years on the Ross Ice Shelf (RIS) between Ross Island and MBL to constrain the mantle structure and dynamics of the Ross Sea Embayment. These stations would take advantage of the presence of the ice shelf to fill a major ocean-covered geological gap within Earth's least studied extensional continental province and would link data sets collected in the TAM transition/Plateau region (TAMSEIS) and in West Antarctica (POLENET) to greatly improve resolution of mantle features beneath Antarctica. Deployment on the ice shelf offers the opportunity to collect seismic data without the expense, logistical complexity, and iceberg hazards associated with ocean bottom seismograph deployments, and limited pioneering deployments on the ice shelf show excellent recording of P waves and 8-50 s Rayleigh waves. Tomographic models developed from this data will be used to choose between competing models for the dynamics of the Ross Sea. In particular, we will investigate whether low velocity hot mantle is localized in the vicinity of Ross Island and the MBL Dome. Alternatively, a broad region of hot mantle, including the Eastern Ross Sea, would indicate distributed recent tectonic activity and call into question models proposing that Eastern Ross extension ceased during the Mesozoic. These data will also allow us to investigate the deeper structure (gt 200 km) to evaluate the possible role of mantle plumes and/or small- scale convection in driving regional volcanism and tectonism across the region. 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. Belen Reflection Test http://www.passcal.nmt.edu/scheduledetails/exptnumb/201436 The is a small test of the viability of using railroad noise as the source of seismic energy for p wave refraction and reflection imaging of the subsurface using seismic interferometry. These results are desired to inform a proposal now in development which is based on applying this speculative methodology.