Indo-Australian Plate Action

The mid-ocean ridges of the Indian ocean continue to drive the Indian and Australian plates north and north east and that continues to cause issues - aka: earthquakes - all along the convergent boundaries those plates "share" with the Asian and Pacific plates.  A 6.1 quake yesterday at the northeast corner of the Indian plate in southern China caused well over 100 deaths, thousands of injuries and destroyed tens of thousands of buildings.  Over the last week, quakes of magnitudes just below that follow all along that Indo-Asian boundary and the shaking continued with lots of 4 and 5 magnitude quakes following the island arcs created by the subduction of the northern edge of the Aussie plate with the basalt of the Pacific sea floor.  Just a guess...but that is likely to continue...for the next 10 to 50 or 100 million years.
Across the Pacific, central and northern South America were shifting and shaking pretty good over the last 7 days.  A 6.3 quake in southern Mexico in late August leads the list but the quakes continued down the isthmus that is central America and all the way down to Peru along the western edge of South America.
The US was mostly quiet this week; small quakes in California, Alaska and fracking quakes in Oklahoma were about it.  Central Va. has been still since the 2.1 shake the last Friday in August and as we approach the 3rd anniversary of the quake that changed thinking along the east coast those of us in the shaky zone would like to see it stay that way.  If wishes were horses...  We know that quiet is not something the earth is likely to be, for at least another billion years or so, get out and enjoy what ever the planet throws your way, today on Earth.

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.

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.

3.2 in CentralVaQuakeZone

The plate boundaries keep shifting, sending waves of energy through our planet but there are little reminders in off boundary sites, as well. The Central Va. Earthquake Zone got that reminder Wednesday night with a good little shake centered along the Powhatan/Amelia county border. For those of us in Louisa that felt it, there was no sound; something we've come to expect with our hundreds of after shocks.  It felt like a quake, shaking for several seconds, but the lack of sound left me wondering, what the...  Just farther away than the many in my neighborhood.
Oklahoma, formerly quite quiet, continues to experience quakes in the 2 - 4 Richter range every day. That started soon after fracking began in earnest in the area, a connection, no doubt, denied by the oil giants blowing up the earth to release the hydrocarbons we Americans crave but don't want to pay the the true cost of.  The earth just does what it does, we blow it up, it shifts to adjust, action/reaction; a clever guy named Newton pointed that out several hundred years ago.  We know it but don't want to "believe" it if we don't like the reaction(Carbon dioxide and global warming??).  Want jobs and cheap oil, better be willing to hang on Oklahoma!!

4.1 in South Carolina

Southwest South Carolina got rocked yesterday with a 4.1 quake, an uncommon but hardly unknown event for the area still digging out and rewiring from the recent snow/ice storm that hammered the entire east coast. Charleston, SC has been the epicenter of large quakes in the past - and, guess what, likely in the future- so this recent quake is hardly a big surprise.  The problem with earthquakes is that they ARE always a surprise, no real warning, just a jolting realization that the world you take for granted as stable really isn't. Central Va. got that reminder 2 1/2 years ago, Japan a big reminder about 3 years ago and if you live on the ring of fire or near any of  the plate boundary "zones of shake" you too, always have that thought of potential shakiness not far below you level of consciousness.
Current geologic thought, in explanation of the shake zone near SC/GA's Savannah River, postulates that the state boundary/river is an old suture zone formed during the smashing and crashing that formed Pangaea. When the rift zone that has lead us to the Atlantic Ocean began to form and separate North America and Africa a chunk got left behind, the edge of that chunk (and therefore weak spot - and rivers find the weak spots) being the Savannah River that now separates the two states (going back to a decree creating Georgia out of the Carolinas). Old fault zones are hard to see in the deeply soil covered east but are there nonetheless, ready to slip and slide when unseen pressures build and need release: an earthquake.
Oklahoma continues to be on the daily list, almost as common as California and Alaska. I'm not sure what's going on out there, I never felt any when working in the area (although I was mostly in western OK). I'm still guessing and blaming fracking and am still guessing the oil & gas industries, blowing up the earth in the area to slurp out the fossil hydrocarbons craved by ALL Americans, are still in denial of any connection at all to the quakes; no couldn't be us...
Hope your world is not shaky, today on Earth.

Greek Aftershocks and Other Good Shakes

Aftershocks in the Richter 4's continue off the coast of Greece following the 6.1 quake 3 days ago. Burma stays on the list with another 5.1 quake and Iran has a couple in the mid-4's; shaky along the southern Eurasian boundary. Japan and the Solomon Isles register quakes in the low to mid-5's and while not large, Indonesia has quakes on the list. The eastern edge of the Philippine plate has calmed a little after a few shaky days.
In the western hemisphere, Chile, a frequent visitor to any earthquake list is back today with a 5.5 quake and the North Atlantic Ridge (Reykjanes Ridge, actually) has been rocking of late; today a 5.1 with lots of slightly smaller quakes over the last several days.  Things have calmed in Bolivia - earthquake wise, anyway, if not politically, after a pretty good shake a few days back.
In the US, Utah, Oklahoma and Arkansas are back/still on the list (yes, Cali and Ak, too), a little more than probably any of those states would like. Respectively, 4.0, 3.2 and 2.6 - wonder how many are related -denied, of course- to fracking or other human/oil/water related activities??
But, what are we going to do on this cracked and broken and shifting planet? Hang on and get out and enjoy (a snowy), Today on Earth.

Greece & Burma Shakes

A 6.0 quake rocked an island of the coast of Greece today a little before 9:00 EST followed by a 5.0 aftershock; more aftershocks are likely to follow. Burma also got a shake up today (evening there)with a 5.8 quake. And, while both are near or on plate boundaries they are not frequent visitors to the list. Tonga with a quake, no shock there; California, Alaska, Indonesia, Japan not a surprise but there is likely a bit of scrambling in Greece and Burma. Both quakes are so recent, I've heard no damage reports; 6.0, in Greece, there will be damage.
The Central Va. zone is quiet these days, the USGS placing (or attempting to place - the ground's been frozen for some time) seismometers more heavily in the region to keep a better eye on the local shifting and shaking. Too bad the "new and improved" USGS earthquake website doesn't allow you to zoom in on exactly where the local aftershocks occured - or I haven't figured out how to, and I have tried and tried with no luck - or reply to my emails to the USGS. Let's hope the the aftershocks continue to diminish so the lack of info won't matter.

Still Shakin', Central VA

As word was passed on through local news of the placement of seismometers across the Central Va. Equake zone by the US Geological Survey the old fault zone responded; a little rumble and a tiny shake this cold, wet morning.  It hasn't shown up on the daily earthquake list, may have been below 1 on the Richter scale, but did remind those of us in the heart of the zone of our residence on a less than stable portion of the big planet. Not sure seismometers are being place on this raw day but be nice to have more quake detection in our "newly" rediscovered quake zone.
No big news elsewhere, so far, for 2014. Plate boundaries are where the action is. Oklahoma has become a steady, low level, standard on the US list. I'm not sure of its ancient plate edge boundary history, maybe the edge of a billion year old Central North American rift zone, maybe there is serious fracking going on out there on the edge of the plains that's adding to the old breaks... It's a bold geologist that claims to know all the causal agents inside this large, spinning chunk of rock we have the pleasure to ride upon. A 2.2 shake in the Charleston, SC. area yesterday delivered the same reminder we just received from the planet, "heh, don't forget, you live in an earthquake zone".
Louisa Co. HS will be conducting a quake drill on a nice day sometime soon but as a teacher of Earth Science, my new students have already been reminded. It's a shaky, random-ish world, be ready to hang on, today on Earth!

No Surprises: Quakes at Plate Boundaries

A quick glance at the new Earthquake site (I hesitate to say improved...) shows the usual suspects still slipping and sliding away. The rim of the Pacific dominates the scene, as is to be expected with the encroaching continents gradually stuffing away the basaltic crust of Earth's largest ocean. The mid-ocean ridges, while mostly thought of as producing the new crust that is moving the plates around, still has lots of transform/strike-slip faults that offset the ridges with plenty of quakes themselves.
We are also reminded that while Italy is part of Europe it wasn't always. The forces gradually shrinking the Mediterranean Sea are also still pushing Italy, Spain, Greece and southeastern Asia northward and the result of that movement: earthquakes. And, while the winter olympics could be disrupted by human conflicts the internal issues of the earth itself formed those mountains and could shake them up again at any time. Hang on!
The Central Va. quake zone has been quiet for a month or so - and let's hope it stays that way. The walls of our new high school are rising and we don't need any new shakes to cause new problems. But...let's face it, the earth doesn't care and it's going to keep doing what it does...for several billion more years. Get out and enjoy your short ride on the big planet, shaky though it may be.