Visualization of the seismic waves and permanent displacements
- 1. Visualization of the seismic waves and permanent displacements Ronni Grapenthin1 The ARIA Team2 Jeffrey Freymueller1 1 Geophysical Institute, Univ. of Alaska Fairbanks 2 Susan Owen, Jet Propulsion Laboratory Angelyn Moore, Jet Propulsion Laboratory Frank Webb, Jet Propulsion Laboratory Mark Simons, Caltech April 10, 2011 Grapenthin et al. (UAF–GI) April 10, 2011 1 / 10
- 2. Tectonic Setting Pacific plate moves westward and collides with Japan (Okhotsk Plate), subducts underneath this plate interaction drives earthquakes offshore Japan Figure: USGS, http://earthquake.usgs.gov/earthquakes/world/japan/031111_M9.0prelim_geodetic_slip.php Grapenthin et al. (UAF–GI) April 10, 2011 2 / 10
- 3. Background For some background on plate mechanics, watch the following video made available through the Education and Outreach Program of IRIS (www.iris.edu/educate). Grapenthin et al. (UAF–GI) April 10, 2011 3 / 10
- 4. Japan GEONET: Dense continuous GPS array started in 1993 by Geospatial Information Authority (GSI) of Japan with about 210 sites) 1995 Kobe earthquake tragedy resulted in intensified earthquake research see Sagiya (2004) for more details today: more than 1200 continuous GPS stations Grapenthin et al. (UAF–GI) April 10, 2011 4 / 10
- 5. Permanent deformation measured by GPS 130 135 140 145 ARIA Preliminary Post and Coseismic 45 Displacements from Mw9.0 Sendai-Oki Earthquake 45 40 40 arrows show permanent horizontal displacements red: Mw 9.0 event at 05:46:23 UTC 35 35 blue: mainly Mw 7.9 event near Tokyo at 1m 06:26:12 UTC 1m 30 30 Figure shows horizontal displacements based on ARIA verion 0.3 position estimates for GEONET stations. Coseismic displacement is shown in red, and first 8 hours of postseismic motion is shown in blue, including motion caused by aftershocks. Bars at end of vector show 95% error estimate. Solutions courtesy of ARIA team at JPL and Caltech (email aria@jpl.nasa.gov or aria@caltech.edu). All original GEONET RINEX data provided to Caltech by theGrapenthin et al. (UAF–GI) Geospatial Information Authority (GSI) of Japan. April 10, 2011 5 / 10
- 6. The displacement field at 5:50 UTC is the sum of . . . Grapenthin et al. (UAF–GI) April 10, 2011 6 / 10
- 7. . . . permanent displacement . . . Grapenthin et al. (UAF–GI) April 10, 2011 7 / 10
- 8. . . . and seismic waves (watch for those in the video) Grapenthin et al. (UAF–GI) April 10, 2011 8 / 10
- 9. Preliminary observations from the animation the actual slip of the Mw =9.0 earthquake is captured in frames 05:47:30-05:49:00 body waves (S-wave), causing small displacements, traverse the array at about 8 km/s (this is apparent velocity, not S-wave velocity) surface wave, causing large displacements, travels at about 5 km/s Grapenthin et al. (UAF–GI) April 10, 2011 9 / 10
- 10. Links Preliminary Geodetic Slip Model of the 2011 M9.0 Tohoku-chiho Taiheiyo-oki Earthquake (USGS): http://earthquake.usgs.gov/earthquakes/world/japan/031111_M9.0prelim_geodetic_slip.php Geohazards Supersite website – preliminary results: http://supersites.earthobservations.org/sendai.php Seismic wave propagation recorded on dense strong-motion seismograph networks in Japan (K-NET/KiK-net): http://outreach.eri.u-tokyo.ac.jp/eqvolc/201103_tohoku/eng/#knet R. Grapenthin, Kinematic GPS solutions: http://gps.alaska.edu/ronni/sendai2011.html Grapenthin et al. (UAF–GI) April 10, 2011 10 / 10