A couple updates on volcanic rumblings on the west side of the Pacific Ocean. Tongariro
Earthquake depth (top) and magnitude (bottom) at New Zealand's Tongariro since July 11, 2012. Figure courtesy of GNS Science. The earthquakes that began in mid-July at Tongariro in New Zealand are continuing - 99 earthquakes since July 11. According to the latest GNS Science update, the earthquakes abated briefly before picking back up over the last few days. In that update, GNS Science had a few plots showing the occurrence and depth of the seismicity (see above) and it appears that the earthquakes are mostly between 1-8 km depth and slowly increasing in magnitude, now at ~M2-3. The higher proportion of volcanic gases (versus hydrothermal gases) at Tongariro is also continuing. GNS Science will be increasing spring and fumarole testing to see what sort of new magmatic input might be appearing at the volcano and GPS units will be installed to look for potential ground deformation. Again, all this activity might not lead to anything as this seismicity and increased volcanic gases could just be an intrusion of magma at depth that will not erupt, but Tongariro will continue to be closely watched. UPDATE: Here's a link to a cool 3D plot of seismicity under the Tongariro area since 2009 put together by Eruptions reader Geolurking. The Lake Taupo region is very evidence to the north of Tongariro/Ruapehu, along with some potential for seeing the hydrothermal systems under Tongariro and Ruapehu. Philippines 2012 has been a fairly quiet year in the Philippines, volcanically-speaking. Even volcanoes like Mayon are pretty quiet these days - the latest PHIVOLCS update reports that little-to-no seismicity has been felt, SO2 emissions are under 100 tonnes/day and no deformation has been noted since February of this year. Meanwhile at Taal, the lake waters in caldera have become cooler and less acidic while GPS measurements are showing deflation since August of 2011. This all suggests that the rumbling at Taal in 2011 was likely an intrusion that has since ceased.
