Tuesday, June 24, 2014

Big Quakes Straddle the IDL

Two major quakes occurred today within a couple of degrees of the International Dateline: first a 6.9 magnitude quake, quickly followed by a 6.6 quake, rocked the southern reaches of the line just north of New Zealand and the northern quake, with 10 times more ground movement at 7.9, shook up the western Aleutians of Alaska just to the east of the dateline and sent tsunami warnings flying around and across the Pacific .  Tsunami warnings for both big quakes have now been cancelled with sea level changes of less than a foot even near the epicenters.  Aftershocks continue with great frequency in both regions making today's USGS list rather lengthy and almost constantly updating as new shakes occur.  If you're not near the line where the old day ends and the new begins you are likely in a quiet zone today, but if you are reading this from earth, just remember that could change...at most any time, Today On Earth.

Tuesday, June 10, 2014

A Quiet, But Still Shaky, Quake Week

While those at the epicenters of the last few days of quakes may not think it was quiet, they should get over it because they all live on plate boundaries and that's where the quakes are! Nothing above 5.7 for the entire 7 day period and most all are at subduction zones around the Pacific and the ongoing India/Asia collision (ongoing for 40 or so million years). No surprises! Earth is still exhaling heat and that heat is slowly pushing the thin, broken pieces of the lithosphere about on the weak, plastic/gooey/oozy layer of the mantle, the asthenosphere.
We see what's happening, have a handle on why it's happening, know where the quakes and volcanoes are going to be and are working on the details but it's only been 50 years, so saying we understand it all would be a bit pompous.  It appears this planet has been trying to chill down ever since it all came together 4.5ish billion years ago and plate tectonics is the result of that cooling.  But it was hot when it formed and it's a big chunk of rock (tiny in the universe picture but... we aren't in the whole universe, only here) and lots of mass holds heat nicely.  Radioactive elements, we now know, break down and add to the heat so, I'm guessing the heat loss, plate movement, earthquake and volcano scene will continue for some time to come.  Longer than we can really be concerned about...
Hang On!! Somewhere, at any time things WILL get shaky, Today On Earth.