Wednesday, January 29, 2014

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.

Sunday, January 26, 2014

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.

Friday, January 10, 2014

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!

Saturday, January 4, 2014

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.