Earthquakes...

A couple of times a week I check out the “Recent Seismic Activity” link at right, which shows the latest data collected by the seismometer installed in my home office (about four feet from where I'm typing this).  Usually there will be one or two entries posted each week.  This time, there were four entries just from the last two days – and they were a large enough magnitude that I knew they must be from relatively close earthquakes.

The map below shows the location of the cluster of small earthquakes (largest one is magnitude 3.8), located about 30 miles ENE of our home.  Not close enough to be worrisome, but certainly closer than most earthquakes the seismometer sees!  The cluster is almost due east of Mt. Laguna, close to S2 near the mouth of Canebrake Canyon.  This is an area I know quite well, as I walk there looking for Desert Lilies many winters.

Earthquake!

Yesterday at 9:56:06 Pacific time there was a magnitude 4.7 earthquake near Anza, California.  There were also a number of smaller quakes both before and after the big one.  I was outside walking our dogs when the shaking hit our house about 15 seconds later, and I never felt a thing (see seismograph below, from the seismometer in our house).  I did hear a neighbor's dog start howling mournfully at exactly the time the quake hit us, no doubt reacting to it.  The epicenter is about 77 km (44 miles) from our house, implying a seismic wave propagation speed of around 5 km/second, as expected.

Debbie was inside our house at the time, and she reports audible rumbling just before the main shock hit.  That is exactly what the seismograph shows, with smaller accelerations for about 10 seconds before the “big” secondary wave hit us at 9:56:31 (note that the seismograph is in UTC time, 7 hours later than Pacific time).

Earthquake!

Well, yesterday, a little teensy one, and quite a long way away.  What makes this one interesting is that the seismometer in our house captured it (see below).

USGS says that the earthquake occurred on 2/23 at 04:40:14 UTC.  Our seismometer shows the first burst of primary wave at 04:40:33 – 19 seconds later.  The location of the earthquake (USGS) is 109 kilometers from our house, yielding an average primary wave speed of 5.75 km/s, well within norms for primary waves.  By collecting lots of data like this, for many earthquakes and from many locations, USGS is building up a huge dataset that will let them learn a great deal about the composition of the earth's crust in the areas where they have good coverage (Southern California is one of them)...

Earthquake Captured!

Early this morning (2:36:02 Pacific time, 10:36:02 UTC) there was a fairly large earthquake (6.3 magnitude) off the coast of northern Mexico.  The epicenter was 305 km (about 183 miles) SW of our home.  At that distance, of course we never felt a thing.  But...the USGS requested data from the seismograph they installed in our home, and the graph at right shows what it “saw”.

This is the first seismogram I've ever actually tried to read.  I found several articles about reading them; this was the most useful.  If I'm understanding this correctly, I'm seeing the P-waves reaching us at about 10:36:46 UTC, or 44 seconds after the quake actually occurred.  That works out to a speed of 305/44, or 6.93 km/s – fast for a P-wave.  Then I'm seeing the S-waves reaching us at about 10:37:17 UTC, or 75 seconds after the quake actually occurred.  That works out to a speed of 4.07 km/s – again fast for an S-wave.  From what I've been reading, these seismograms are very challenging to extract good information from – both the amplitude and the timing of them are highly dependent on the geologic structures and material types between the earthquake and the seismometer.  I think I'll leave that to the experts :-)

But I do think it's kind of cool to be able to see the earthquake on an instrument in my house!

NetQuakes...

Something like two years ago, I first read about the U.S. Geological Survey (USGS) “NetQuakes” program.  Basically the USGS wants to get a denser network of seismographs in certain earthquake-prone area, such as southern California.  To reduce the cost of such a network, they came up with a capital idea: enlist a network of volunteer “seismograph hosts”.  Each of these hosts had to have a home with a concrete slab, power, and Internet access.  That describes just about every house around here, including ours.  So I signed up to be a volunteer.

Nothing whatsoever happened after that, until last week – when completely out of the blue, a nice young fellow from USGS called me and asked if I was still interested.  Of course I said yes, and last Thursday he showed up with a GeoSIG IA-2 “Internet Accelerograph” (PDF datasheet) just like the one at right, and a few tools.  I had picked out a spot underneath my IT gear that he thought was just dandy, and in just a few minutes he had the thing installed, powered up, checked out, and connected to the Internet (via WiFi!).  The bracket that holds the instrument (seen in the photo as the metallic plate on the bottom) is bolted to my slab and leveled.  The instrument itself snicks right into that bracket – so as my slab moves, the instrument itself moves.

And exactly what is the instrument?  The summary: a three-axis accelerometer with some smarts around it to pick the “strong motion” events to bother reporting, and to record not only the event itself but some time both before and after it.  The whole thing is running on an ARM processor; the OS is Linux.  Quite the modern piece of gear!

The data it collects is published up to the Internet and is publicly accessible.  The page for my particular instrument is here; a map of all the instruments is here (from here you can get to the data for any instrument).  The image below shows what the seismograph (all three axes) produces for an event it records:

If you'd like to volunteer for NetQuakes, here's the signup page.

Your Morning WTF: Scientists Convicted...

An Italian court has convicted 7 scientists and experts of manslaughter, for failing to predict an earthquake that killed hundreds of people.  They have appealed, and hopefully the conviction will be overturned by a more rational higher court.  Hopefully.

Meanwhile, these scientists live in fear of long prison sentences.

Maybe the Pope will intervene.

Good grief.

Doom...

Smooth Atacama Boulders...

In the extreme dryness of the Atacama desert in Chile, there are large fields of boulders on the flat desert floor.  The midsections of these boulders are worn smooth.  Such smoothing is normally caused by erosion involving water, but this desert has virtually none.  So why are those boulders smooth?  In a word: earthquakes.

Earthquake!

My folks live about 7 miles from the epicenter of yesterday's earthquake in Virginia.  They're fine, and their house is fine.  But they didn't like it very much!

There's a detailed USGS report, location maps, a science article, and realtime maps (where the picture at right came from).  In this morning's news, I read of some damage in Culpepper and in Washington, D.C., but all-in-all it looks pretty minor.

I sense a new-found level of respect from my East Coast colleagues, especially when it dawns on them that the Virginia quake was quite small compared to some we've had out here...

Reunited...

It's in Japanese, but really, no words are required...

Rescued Dog and Its Owner Reunited...

Saturday I wrote about the dog rescued off the coast of Japan, quite possibly the last survivor of the earthquake and tsunami of three weeks ago.  This morning comes the news that the dog and its owner have been reunited.  I couldn't find pictures or video, but who cares?  What a nice way to start the morning...

Japan's Last Quake Survivor?

Three weeks on flotsam, with no food or water – then rescued by men who had given up all hope of finding any survivors.

That's one happy dog (click to enlarge).  I sure hope his owner has survived and can be found.  If not, somehow I'm certain this little fellow will find a loving home.

This story (and these videos) sure put a smile on my face this morning...

On Approach to Tokoyo Airport During the Earthquake...

Via reader Dr. Simi L., this message from a pilot who was in the air, piloting a passenger jet, on final approach to Tokoyo airport when the earthquake hit a couple weeks ago:

I'm currently still in one piece, writing from my room in the Narita crew hotel.

It's 8am. This is my inaugural trans-pacific trip as a brand new, recently checked out, international 767 Captain and it has been interesting, to say the least, so far. I've crossed the Atlantic three times so far so the ocean crossing procedures were familiar.

By the way, stunning scenery flying over the Aleutian Islands. Everything was going fine until 100 miles out from Tokyo and in the descent for arrival. The first indication of any trouble was that Japan air traffic control started putting everyone into holding patterns. At first we thought it was usual congestion on arrival. Then we got a company data link message advising about the earthquake, followed by another stating Narita airport was temporarily closed for inspection and expected to open shortly (the company is always so positive).

From our perspective things were obviously looking a little different. The Japanese controller's anxiety level seemed quite high and he said expect "indefinite" holding time. No one would commit to a time frame on that so I got my copilot and relief pilot busy looking at divert stations and our fuel situation, which, after an ocean crossing is typically low.

It wasn't long, maybe ten minutes, before the first pilots started requesting diversions to other airports. Air Canada, American, United, etc. all reporting minimal fuel situations. I still had enough fuel for 1.5 to 2.0 hours of holding. Needless to say, the diverts started complicating the situation. Japan air traffic control then announced Narita was closed indefinitely due to damage. Planes immediately started requesting arrivals into Haneada, near Tokyo, a half dozen JAL and western planes got clearance in that direction but then ATC announced Haenada had just closed. Uh oh! Now instead of just holding, we all had to start looking at more distant alternatives like Osaka, or Nagoya.

One bad thing about a large airliner is that you can't just be-pop into any little airport. We generally need lots of runway. With more planes piling in from both east and west, all needing a place to land and several now fuel critical ATC was getting over-whelmed. In the scramble, and without waiting for my fuel to get critical, I got my flight a clearance to head for Nagoya, fuel situation still okay. So far so good. A few minutes into heading that way, I was "ordered" by ATC to reverse course. Nagoya was saturated with traffic and unable to handle more planes (read- airport full). Ditto for Osaka.

With that statement, my situation went instantly from fuel okay, to fuel minimal considering we might have to divert a much farther distance. Multiply my situation by a dozen other aircraft all in the same boat, all making demands requests and threats to ATC for clearances somewhere. Air Canada and then someone else went to "emergency" fuel situation. Planes started to heading for air force bases. The nearest to Tokyo was Yokoda AFB. I threw my hat in the ring for that initially. The answer - Yokoda closed! no more space.

By now it was a three ring circus in the cockpit, my copilot on the radios, me flying and making decisions and the relief copilot buried in the air charts trying to figure out where to go that was within range while data link messages were flying back and forth between us and company dispatch in Atlanta. I picked Misawa AFB at the north end of Honshu island. We could get there with minimal fuel remaining. ATC was happy to get rid of us so we cleared out of the maelstrom of the Tokyo region. We heard ATC try to send planes toward Sendai, a small regional airport on the coast which was later the one I think that got flooded by a tsunami.

Atlanta dispatch then sent us a message asking if we could continue to Chitose airport on the Island of Hokkaido, north of Honshu. Other Delta planes were heading that way. More scrambling in the cockpit - check weather, check charts, check fuel, okay. We could still make it and not be going into a fuel critical situation ... if we had no other fuel delays. As we approached Misawa we got clearance to continue to Chitose. Critical decision thought process. Let's see - trying to help company - plane overflies perfectly good divert airport for one farther away...wonder how that will look in the safety report, if anything goes wrong.

Suddenly ATC comes up and gives us a vector to a fix well short of Chitose and tells us to standby for holding instructions. Nightmare realized. Situation rapidly deteriorating. After initially holding near Tokyo, starting a divert to Nagoya, reversing course back to Tokyo then to re-diverting north toward Misawa, all that happy fuel reserve that I had was vaporizing fast. My subsequent conversation, paraphrased of course...., went something like this:

   "Sapparo Control - Delta XX requesting immediate clearance direct to Chitose, minimum fuel, unable hold."
   "Negative Ghost-Rider, the Pattern is full" <<< top gun quote <<<
   "Sapparo Control - make that - Delta XX declaring emergency, low fuel, proceeding direct Chitose"
   "Roger Delta XX, understood, you are cleared direct to Chitose, contact Chitose approach....etc...."

Enough was enough, I had decided to preempt actually running critically low on fuel while in another indefinite holding pattern, especially after bypassing Misawa, and played my last ace...declaring an emergency. The problem with that is now I have a bit of company paperwork to do but what the heck.

As it was - landed Chitose, safe, with at least 30 minutes of fuel remaining before reaching a "true" fuel emergency situation. That's always a good feeling, being safe. They taxied us off to some remote parking area where we shut down and watched a half dozen or more other airplanes come streaming in. In the end, Delta had two 747s, my 767 and another 767 and a 777 all on the ramp at Chitose. We saw two American airlines planes, a United and two Air Canada as well. Not to mention several extra Al Nippon and Japan Air Lines planes.

Post-script - 9 hours later, Japan air lines finally got around to getting a boarding ladder to the plane where we were able to get off and clear customs - that however, is another interesting story. By the way - while writing this - I have felt four additional tremors that shook the hotel slightly - all in 45 minutes.

Cheers, J.D.

Earthquake Liquification Video...

One of the most under-appreciated effects of earthquakes is soil liquification.  In certain areas (including many in California), this phenomenon is actually the single largest risk factor to man-made structures.  This video shows one of the visible symptoms: surface water appearing out of nowhere.  What it doesn't show is damage-causing mode – the loss of stiffness in the soil, turning it essentially into a liquid, removing all support for structures built upon it.

The most interesting stuff starts about halfway through the video, so be patient:

Japan Earthquake...

A magnitude 8.9 earthquake hit Japan last night, and aftershocks are continuing as I write this.  Current map here.  News reports are indicating at least 40 people were killed outright, and many more are missing.  Japan's eastern coast was struck very quickly by a huge tsunami, which is the cause of most of the devastation.

If there was ever a country prepared for earthquakes, it is Japan.  Knowing this provides some comfort as I think of the impact on people there...

Initial reports are also indicating that Japan's quake-conscious building codes paid off – there was little of the sort of house-of-cards collapsing seen after quakes in places like Iran or Turkey.

There's a tsunami watch out for basically the entire Pacific Basin.  Estimates for the tsunami's arrival at Hawai'i are shortly after 3 am local time (5 am PST).  Fingers crossed and thumbs pressed.  The estimates even list San Diego arrival (around 8:40 am PST), but with much smaller (and most likely insignificant) magnitude.

Just when you think mankind's problems are big and significant, along comes Mother Nature with a little hiccup to remind us all that we are but insignficant nothings, granted our meager existence at her whim...

News Overload...

There's so much happening in the world right now...I'm overwhelmed.  I have the sense that we're all witnessing something that potentially is of the same historical import as the fall of the Soviet Union.  It seems like the world's attention isn't particularly focused on the events in the Middle East.  They're in the news, but for a lot of it I have to dig a bit on the inter-tubes.  But the news is there, though it's very hard to be sure what to place credence in.

Libya, Yemen, Iran, Bahrain all appear to have active revolts taking place (though with greatly differing prospects of success).  Gadaffi is slaughtering hundreds of his subjects.  The governments of Syria, Saudi Arabia, Jordan, Qatar, and UAE are all taking various actions designed to tamp down any revolutionary efforts – though for most of these it's not clear how much those actions were actually needed to maintain the current regimes' power.  Our president says nothing at all about the situation; offers no support, exhibits no leadership either domestically or internationally.  This shames me, as this is exactly the sort of situation in which the world looks to the U.S. for leadership.  Where will the leadership come from?  China?  Russia?  France?

One thing that keeps running through my mind are the predictions of the “domino effect” in the Middle East by a host of neocons in the early 2000s, and by Natan Sharansky.  The scenarios they outlined as likelihoods bear a striking resemblance to what's actually happening...

This morning I read of the earthquake in New Zealand; as I read the death toll stood at 65, with hundreds still unaccounted for.  I visited the city of Christchurch back in the '70s, while I was in the U.S. Navy; somehow my having been there makes the devastation seem a little more real than the typical news report.  There's little any of us can do to help; all we can do is hope for the best...

Earthquake!

Last night at about 9:30 pm, a moderate earthquake woke us up and had us running for a doorway to stand in.  It lasted perhaps 25 or 30 seconds.  Being nighttime, there was little ambient noise – so the rumblings associated with the quake were quite audible.  In fact, it was the noise that alerted me to the fact that there was an earthquake in progress, rather than the shaking.

The USGS web site puts the magnitude at 5.7, and the epicenter at a few miles southeast of Ocotillo. 

Rocking and Rolling: Update...

We've not felt any aftershocks at our home, but as you can see from the map at right there have been a great many of them (all much smaller than the magnitude 7.2 initial quake).

Check back with the USGS site for updates...

Rocking and Rolling...

We just felt a strong earthquake – lots of sideways motion, subsonic rumbling, and of quite long duration (about 45 seconds at a guess).  The USGS initial automated report puts it at magnitude 6.9, about 20 miles south of the Mexican border.  That's roughly 60 or 70 miles from our house...

The report is preliminary and these often get revised.  USGS map at right and info below; click to enlarge...

Earthquake!

Ok, so it was an itsy-bitsy teenie-weenie earthquake: a whopping magnitude 1.2. I'm pretty sure you couldn't feel that even if you were standing on the epicenter. The seismograph charts at right show the story, and you can read the details yourself, or look at a map of its location (not far from the Jamul Indian reservation).

Hmm... Maybe Mother Nature is practicing, just in case the casino gets built?

Quake!

I'm sure you've heard the news about the earthquake near Los Angeles yesterday – a 5.4 temblor (the big blue square on the map at right). This is a sort of medium-sized earthquake, but the most powerful one we've had since the Northridge quake in the early '90s.

At the time it struck, I was working in my company's offices in Solana Beach, in the building the employees affectionately call the “wooden spaceship” (for its slight resemblence to the disk of Star Trek's Starship Enterprise). From our perspective there were two phases: first a kind of exaggerated rumbling that many of us thought was caused by heavy footsteps, followed in a few seconds by distinct transverse waves (side-to-side motion) large enough to move the building an inch or two. Wooden buildings have a bit of “give” to them, so they move a little more than a steel or concrete building of the same size would. Nobody panicked, or was even truly frightened, but everybody was on alert to see if the quake would get any worse...

We had no damage of any kind in our building, but at that moment we had no idea where the quake's epicenter was. Several of us are very familiar with the USGS earthquake web site for California and Nevada (the source for the picture above). Moments after the shock wave hit us, several people had this site up on their screens. Within a minute or two of the shock hitting us, the initial reports for the quake came in, and the site showed the location and preliminary intensity – quite impressive. Not so many years ago, we'd have had to wait days to get this information, and it wouldn't have been nearly as accurate. For me personally, the news was very comforting: the quake's epicenter was far away from my home. I found out later that Debbie (who was within a few miles of our house when the quake hit) never felt a thing...