PASSCAL Experiments en SEGMeNT 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. AAA (triple A) 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. Mount St Helens aka iMUSH 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. RRISWIV Ocean gravity waves are dynamic, changeable elements of the global ocean environment, affected by ocean warming and changes in ocean and atmospheric circulation patterns. Their evolution may thus drive changes in ice-shelf stability by both mechanical interactions, and potentially increased basal melting, which in turn feed back on sea level rise. Our proposed research is intended to discover, through field observations and numerical simulations, how ocean wave-induced vibrations on ice shelves in general, and the Ross Ice Shelf (RIS), in particular, can be used to infer spatial and temporal variability of ice shelf mechanical properties. The mechanical forcing to be examined involves a broad spectrum of surface gravity waves spanning local wind seas (at periods less than 10 s), sea swell (in the 10 - 30 s period band), and infragravity (IG) waves (periods from about 50 to 300 s). 2014 IBD The IRIS Interns will deploy three BB sensors behind the PIC and leave them deployed for ~5 days. Mt St Helens 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. Sweetwater Collaborative experiments with NodalSeismic and Nanometrics to conduct a mix phase array of continuous recorded nodes with broadband sensors. MAGIC 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. POLENET2 backbone 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. SEISORZ Active-source seismic experiment along one ~500-km-long transect. 800 "Texans" stations spaced ~625 m will record energy from 20 land shots. Goal is to image crustal and uppermost mantle structure in a region of incipient continental rifting.