<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">A very large earthquake (M8.8) struck northern Japan about 2 hours ago. Details below from the USGS. This is similar in size to the 2010 Maule earthquake in Chile. Based on the aftershock locations showing today, it appears to have involved a roughly 500 km long rupture, extending as far south as Tokyo. Check the news for details of damage, tsunami, etc. I don't have any information from Japan yet, although I have emailed some friends there.<div><br></div><div>It is likely that this earthquake has caused a significant displacement of every GPS site in northern and central Japan, plus Korea and parts of northern China. As with the Maule earthquake, it is likely that measurable displacements extend as far as several hundred km to perhaps more than 1000 km from the rupture zone.</div><div><br></div><div>Several IGS08 core sites were certainly or possibly displaced, and other sites used by the IGS (such as Usuda and DAEJ) are likely to have been displaced.</div><div><br></div><div>TSKB definitely, decimeters to meters</div><div>BJFS maybe mm-cm?</div><div>KHAJ maybe mm-cm?</div><div>TNML maybe mm-cm?</div><div><br></div><div>Non-linear motion with time will almost certainly follow for several years or more for sites affected by the earthquake. </div><div><br></div><div>IGS centers should look very carefully at solutions and coordinate estimates for all sites within a sufficient radius around the earthquake rupture before releasing orbit or solution products. </div><div><br></div><div>Within a day or so, preliminary slip models from the USGS and other sources should be available, based on seismic recordings. For the Maule earthquake, these models predicted displacements fairly accurately in the far field (hundreds of km from the rupture), although they did not work so well for near field. I suspect performance will be similar in this case.</div><div><br></div><div>Jeff</div><div><div><br><div>Begin forwarded message:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" color="#000000" style="font: 12.0px Helvetica; color: #000000"><b>From: </b></font><font face="Helvetica" size="3" style="font: 12.0px Helvetica"><a href="mailto:ens@usgs.gov">ens@usgs.gov</a> (USGS ENS)</font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" color="#000000" style="font: 12.0px Helvetica; color: #000000"><b>Date: </b></font><font face="Helvetica" size="3" style="font: 12.0px Helvetica">March 10, 2011 9:28:35 PM AKST</font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" color="#000000" style="font: 12.0px Helvetica; color: #000000"><b>To: </b></font><font face="Helvetica" size="3" style="font: 12.0px Helvetica"><a href="mailto:jeff@kiska.giseis.alaska.edu">jeff@kiska.giseis.alaska.edu</a></font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" color="#000000" style="font: 12.0px Helvetica; color: #000000"><b>Subject: </b></font><font face="Helvetica" size="3" style="font: 12.0px Helvetica"><b>2011-03-11 05:46:23 UPDATED: (M 8.8) NEAR EAST COAST OF HONSHU, JAPAN 38.3 142.4 (dc9d)</b></font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" color="#000000" style="font: 12.0px Helvetica; color: #000000"><b>Reply-To: </b></font><font face="Helvetica" size="3" style="font: 12.0px Helvetica"><<a href="mailto:ens@usgs.gov">ens@usgs.gov</a>></font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><br></div> </div><div> == PRELIMINARY EARTHQUAKE REPORT ==<br><br>***This event has been revised.<br><br><br>Region: NEAR EAST COAST OF HONSHU, JAPAN<br>Geographic coordinates: 38.322N, 142.369E<br>Magnitude: 8.8 M<br>Depth: 24 km<br>Universal Time (UTC): 11 Mar 2011 05:46:23<br>Time near the Epicenter: 11 Mar 2011 14:46:23<br>Local standard time in your area: 11 Mar 2011 05:46:23<br><br>Location with respect to nearby cities:<br> 130 km (81 miles) E (86 degrees) of Sendai, Honshu, Japan<br> 179 km (111 miles) ENE (68 degrees) of Fukushima, Honshu, Japan<br> 188 km (117 miles) SE (145 degrees) of Morioka, Honshu, Japan<br> 376 km (234 miles) NE (37 degrees) of TOKYO, Japan<br><br><br>ADDITIONAL EARTHQUAKE PARAMETERS<br>________________________________<br>event ID : US c0001xgp<br><br>This event has been reviewed by a seismologist at NEIC<br>For subsequent updates, maps, and technical information, see:<br><a href="http://earthquake.usgs.gov/eqcenter/recenteqsww/Quakes/usc0001xgp.php">http://earthquake.usgs.gov/eqcenter/recenteqsww/Quakes/usc0001xgp.php</a><br>or<br>http://earthquake.usgs.gov/<br><br>National Earthquake Information Center<br>U.S. Geological Survey<br>http://neic.usgs.gov/<br><br><br>DISCLAIMER: https://sslearthquake.usgs.gov/ens/help.html?page=help#disclaimer<br><br><br>This email was sent to jeff@giseis.alaska.edu<br><br>You requested mail for events between -90.0/90.0 latitude and <br>180.0/-180.0 longitude <br>for M5.5 at all times. <br><br><br>To change your parameters or unsubscribe, go to:<br>https://sslearthquake.usgs.gov/ens/<br></div></blockquote></div><br><div apple-content-edited="true"> <span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Lucida Grande; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><div style="word-wrap: break-word; -khtml-nbsp-mode: space; -khtml-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Lucida Grande; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><br class="Apple-interchange-newline"><span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Lucida Grande; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><div><br></div><div>Dr. Jeffrey T. Freymueller Office: 907-474-7286</div><div>Geophysical Institute Fax: 907-474-7290</div><div>University of Alaska, Fairbanks Home: 907-479-3550</div><div>PO Box 757320 Cell: 907-378-7556</div><div>Fairbanks, AK 99775-7320 email: <a href="mailto:jeff.freymueller@gi.alaska.edu">jeff.freymueller@gi.alaska.edu</a></div><div>URL: <a href="http://www.gps.alaska.edu/jeff/jeff.html">http://www.gps.alaska.edu/jeff/jeff.html</a></div><div><br></div><div>Download Alaska GPS data: <a href="ftp://gps.alaska.edu/pub/gpsdata/">ftp://gps.alaska.edu/pub/gpsdata/</a></div><br class="Apple-interchange-newline"></span></span></div></span> </div><br></div></body></html>