Quiescent deformation of the Aniakchak Caldera, Alaska, mapped by InSAR

Research Article| January 01, 2006 Quiescent deformation of the Aniakchak Caldera, Alaska, mapped by InSAR Oh-Ig Kwoun; Oh-Ig Kwoun 1 Science Applications International Corporation (SAIC), U.S. Geological Survey (USGS) Center for Earth Resources Observation and Science (EROS), Sioux Falls, South Dakota 57198, USA Search for other works by this author on: GSW Google Scholar Zhong Lu; Zhong Lu 1 Science Applications International Corporation (SAIC), U.S. Geological Survey (USGS) Center for Earth Resources Observation and Science (EROS), Sioux Falls, South Dakota 57198, USA Search for other works by this author on: GSW Google Scholar Christina Neal; Christina Neal 2U.S. Geological Survey, Alaska Volcano Observatory, Anchorage, Alaska 99508, USA Search for other works by this author on: GSW Google Scholar Charles Wicks, Jr. Charles Wicks, Jr. 3U.S. Geological Survey, Earthquake and Volcano Hazards Program, Menlo Park, California 94025, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Oh-Ig Kwoun 1 Science Applications International Corporation (SAIC), U.S. Geological Survey (USGS) Center for Earth Resources Observation and Science (EROS), Sioux Falls, South Dakota 57198, USA Zhong Lu 1 Science Applications International Corporation (SAIC), U.S. Geological Survey (USGS) Center for Earth Resources Observation and Science (EROS), Sioux Falls, South Dakota 57198, USA Christina Neal 2U.S. Geological Survey, Alaska Volcano Observatory, Anchorage, Alaska 99508, USA Charles Wicks, Jr. 3U.S. Geological Survey, Earthquake and Volcano Hazards Program, Menlo Park, California 94025, USA Publisher: Geological Society of America Received: 01 Jul 2005 Revision Received: 22 Sep 2005 Accepted: 26 Sep 2005 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2006) 34 (1): 5–8. https://doi.org/10.1130/G22015.1 Article history Received: 01 Jul 2005 Revision Received: 22 Sep 2005 Accepted: 26 Sep 2005 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Oh-Ig Kwoun, Zhong Lu, Christina Neal, Charles Wicks; Quiescent deformation of the Aniakchak Caldera, Alaska, mapped by InSAR. Geology 2006;; 34 (1): 5–8. doi: https://doi.org/10.1130/G22015.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract The 10-km-wide caldera of the historically active Aniakchak volcano, Alaska, subsides ∼13 mm/yr, based on data from 19 European Remote Sensing Satellite (ERS-1 and ERS-2) interferometric synthetic aperture radar (InSAR) images from 1992 through 2002. The pattern of subsidence does not reflect the distribution of pyroclastic deposits from the last eruption in 1931 and therefore is not related to compaction of fragmental debris. Weighted least-squares inversion of the deformation maps indicates a relatively constant subsidence rate. Modeling the deformation with a Mogi point source locates the source of subsidence at ∼4 km below the central caldera floor, which is consistent with the inferred depth of magma storage before the 1931 eruption. Magmatic CO2 and He have been measured at a warm soda spring within the caldera, and several sub-boiling fumaroles persist elsewhere in the caldera. These observations suggest that recent subsidence can be explained by the cooling or degassing of a shallow magma body (∼4 km deep), and/or the reduction of the pore-fluid pressure of a cooling hydrothermal system. Ongoing deformation of the volcano detected by InSAR, in combination with magmatic gas output from at least one warm spring, and infrequent low-level bursts of seismicity below the caldera, indicate that the volcanic system is still active and requires close attention for the timely detection of possible hazards. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.