Figure 1: Deployment map for the Alaska Amphibious Community Seismic Experiment, with historic earthquakes shown in pink circles.
The Alaska Amphibious Community Seismic Experiment will deploy an onshore-offshore array of seismometers in the east-central Alaska Peninsula region in 2018 and 2019 to study the seismically active Alaska-Aleutian subduction zone. The array includes 85 ocean bottom seismometers and 30 onshore seismometers that will be in the field for ~15 months. The plan addresses the high scientific priorities of the Amphibious Array Futures Workshop report and the GeoPRISMS and EarthScope Science plans in this region of great earthquakes and abundant volcanism.
Figure 2: Seismicity from 1970-2012 for Alaska and vicinity from the Alaska Earthquake Center and USGS PDE catalogs. Figure courtesy of Natasha Ruppert (AEC) and the USArray website.
Several major scientific and logistical criteria were used to design the array.
- Sampling of the megathrust at sufficient density to locate thrust-zone seismicity.
- Sampling across major segment boundaries to capture both locked and creeping sections of the megathrust.
- Spanning the outer rise sufficiently to image serpentinization, e.g. via ambient noise.
- Densifying across one transect to enhance imaging of the entire subduction system from outer rise to far backarc.
- Taking advantage of forearc islands to allow deployment of onshore stations as close to the trench as possible.
- Taking advantage of TA, Alaska Earthquake Center (AEC) and Alaska Volcano Observatory (AVO) stations where possible to maximize efficiency and promotes integration with a larger data set.
- Optimize integration with existing data sets, for example active-source lines.
- Make all data available openly and freely at the IRIS DMC, as soon as they are recovered from instruments and appropriately corrected.