Some better tsunami coverage

I know there's been a general feeling of disgust in the geoblogosphere about the coverage of the recent Chilean earthquake and its associated tsunami. Fortunately, a few news channels have managed to get hold of geologists and actually listen to them properly. And hey, if it happens to have been my undergraduate advisor, even better!

This is a clip of my undergrad advisor (Dr. Chuck Bailey of the College of William & Mary) from WAVY News 10, the local NBC station for the Williamsburg/Hampton Roads/Norfolk area of Virginia. 

Nice job, CB! I wish they'd consult geologists more often. Chuck also blogs about what's going on in the Geology Department at William & Mary - have a look or follow the feed!

Richter or not?

Most of you have probably heard about the earthquake that occurred in Haiti on Tuesday. It's shaping up to be a huge disaster, especially since it occurred in an area that hasn't seen a major earthquake for centuries; when natural disasters haven't occurred within living memory, people become unprepared to deal with them. The poverty of most of the millions of Haitians who were affected has only made it worse, and it's going to be a difficult recovery for them. I encourage everyone to find a charity that will be providing aid (the Red Cross, UNICEF, Doctors Without Borders, and Direct Relief International are just a few) or donate blood through the Red Cross. Even a few dollars or a little bit of blood will help.

It's only natural that a lot of news agencies will report natural disasters, and especially large earthquakes. But over and over again, I hear even the best reports making the same mistake: using the phrase "the earthquake was an X on the Richter scale." A Google News search for "Haiti earthquake Richter" brings up more than 500 references to news articles that use that phrase. It might seem nitpicky, but it always annoys me when the media can't be bothered to use the correct phrasing to describe earthquakes - it's a small misuse of scientific terminology, but if you take a closer look at it, it's a significant one.

The Richter magnitude scale was developed in 1935 by Charles F. Richter of the California Institute of Technology based on measurements made of shallow earthquakes in California. Technically, the way it was developed means that it's the most accurate in California, and when using a specific type of seismograph; it's also not terribly accurate for very large earthquakes or distant ones. Scientists have since expanded on the methods Richter used, which now incorporate even more data that can be recorded about an earthquake. The USGS website about "Earthquake Magnitude Policy" says it this way:

"There is some confusion, however, about earthquake magnitude, primarily in the media, because seismologists often no longer follow Richter's original methodology. Richter's original methodology is no longer used because it does not give reliable results when applied to M> 7 earthquakes and it was not designed to use data from earthquakes recorded at epicentral distances greater than about 600 km. It is, therefore, useful to separate the method and the scale in releasing estimates of magnitude to the public."

As far as the USGS is concerned - and they're usually the ones reporting earthquake magnitudes to the media - the preferred method of referring to magnitudes is with moment magnitude. Again, the USGS says it pretty succinctly:

"Moment is a physical quantity proportional to the slip on the fault times the area of the fault surface that slips; it is related to the total energy released in the EQ. The moment can be estimated from seismograms (and also from geodetic measurements). The moment is then converted into a number similar to other earthquake magnitudes by a standard formula. The result is called the moment magnitude. The moment magnitude provides an estimate of earthquake size that is valid over the complete range of magnitudes, a characteristic that was lacking in other magnitude scales."

Moment magnitude is measured on a logarithmic scale - each step up is many times more powerful than the last. This means that the 7.0 earthquake that happened in Haiti is much more powerful than, say, the ~M 5 earthquake that I felt in Guatemala earlier this year. When talking about earthquakes, official reports nowadays (like the USGS press releases) say the earthquake had a "magnitude of X". This is not to be confused with earthquake intensity, which measures the strength of shaking at any particular location, and is determined mainly by the earthquake's effects on people and structures. (An earthquake rating a I on the Mercalli Intensity Scale would be so small that almost no one would feel it, while the Haiti earthquake would be a VIII or higher, with significant or total destruction and visible effects during the shaking.)


So the takeaway message is to be careful how you talk about earthquake magnitude. If the information is coming from the USGS, it's referring to moment magnitude, and not the Richter scale. Hopefully some of the media will eventually pick up on this, for accuracy's sake if nothing else. 

Using Google Earth to visualize volcanic and seismic activity

I haven't been posting much lately (teaching labs and trying to wrap my head around volcano seismology is eating up my free time), but I have been trying to keep up with new developments. One really neat one is the release of the newest Google Earth and the Oceans layer. My last two labs have been oceanography and waves/tides/currents, so I've been leaning heavily on Google Earth to help my students visualize things. And it works! They're actually engaged, especially since they get to navigate around instead of just watching me give a lecture.

The Oceans layer comes with a lot of other sublayers, including one from National Geographic about plate tectonics, earthquakes and volcanoes. Being a geology geek, I already have several volcano/earthquake layers from the Smithsonian, USGS, etc. So, I thought it might be interesting to compare the old and new offerings.

Here's the first - the Smithsonian Global Volcanism Program's catalog of Holocene volcanoes.

I like this layer because clicking on a volcano pops up the text of the GVP webpage on that volcano, complete with photo and links. What I don't like about the layer is that this is all it does - nothing about plate tectonics, nothing about older volcanoes. You can see where the volcanoes are, but not (at first glance) why. Also, I'd opt for a snazzier symbol; that little X-and-box thing is efficient, but kind of boring.

Then there's the USGS layers for earthquakes. (They don't seem to have a volcanoes layer, but they do have an interactive map of recent activity here). One EQ layer shows earthquakes by age (i.e., in the past hour, day, week, etc.), and the other by depth. I like the clean look of these, the small legend, and the information that pops up for each earthquake, complete with links to the USGS online record and

The most recent earthquakes are shown in red (hours ago), days-old earthquakes in orange, and months-old earthquakes in yellow.

Here the shallower earthquakes are in red and orange, and the deepest are in blues and purples.

I like these because the symbols are easy to read, the legend is simple, and there's information about tectonic plate motions (including rates of movement) and boundary locations. The layers also updates themselves each time you open up Google Earth - very useful if you're teaching a class on plate tectonics, and want your students to keep track of earthquake activity in a particular area. You can even highlight specific types of plate boundaries, which are have their own separate sublayers.

The USGS has one more layer of historical earthquakes, with M3 in the past 90 days, M4 in the past year, and so on up to M9 (since 1970 - only one of these, the 2004 Sumatra earthquake).

No legend or drawn-out plate boundaries on this one, but a wealth of information and popups for each earthquake. It's especially good for highlighting plate boundaries using seismic activity.

Finally there's the new National Geographic plate tectonics layer. They went all out on this one - sublayers for plate boundaries, volcanoes, hot spots, earthquakes, plate motions...the whole shebang. It's actually quite crowded at first. Unfortunately, to download it you have to turn on the main National Geographic sublayer of the Oceans layer, search for the NG symbol in the middle of the Pacific Ocean, and click to download the plate tectonics bit. This is a major drawback for the NG information, and in the future I hope they list their information somewhere instead of making you hunt for it on the globe.

One thing that I severely dislike about this layer is the legend. It's far too large and covers up a significant chunk of the globe. It's not adjustable, either, so unless you immediately memorize all the symbology, you have to keep turning it on and off. The sheer volume of information shown is also distracting - it's better to break it down.

This one shows the plate boundary locations and types, and relative plate motions. Unlike the USGS layer, however, there's no information about rates of movement.

This view shows some of the "Selected Hot Spots". I'm a little iffy on whether all of the locations this layer shows are properly considered hot spots - there's a lot of argument about these phenomena anyway. The bad thing about this layer is that beside displaying the names, there's no pop-up info about these locations, nor is there any explanation of what a hot spot is.

This view is showing the "Notable earthquakes since 1900" and "Quakes since 1900 greater than 6.5 magnitude" layers. Again, no information about the individual events, other than marking their location. I suppose it's useful for highlighting areas of high seismic activity, but it would be much better if there were at least magnitudes and dates listed for each event, so someone could look them up elsewhere.

And, finally, the volcanoes - small triangles are Holocene eruptions, and large ones are eruptions since 1900. Yet again, there's no further information - this is where the Smithsonian layer outstrips the National Geographic one, despite its simplicity.

So what's the final verdict? Use all of them! I'd reserve the National Geographic layers for general overview - showing the locations of plate boundaries, eruptions and earthquakes, for example - but use the USGS and Smithsonian layers for more in-depth examinations. The USGS layer is especially good for teaching seismology and plate tectonics, since it gives information on plate motions and individual seismic events - and links it all to the USGS database.

I'm looking forward to reviewing new layers as I find them, and hopefully I'll get a chance to use them in my teaching.

The Great Southern California ShakeOut

Even though I'm sure this has been mentioned in many places, I promised I'd post on it (in case there's anyone out there who didn't see the first few iterations).

While I was at the Boston NSTA meeting, I ha d the chance to meet a fellow from the Southern California Earthquake Center, and chat with him a bit about the Center's work. I was really impressed by their public awareness campaign (which has a slogan of, appropriately, "Shift Happens", in addition to Dare to Prepare). It often seems to me like the US is poorly prepared even for natural disasters that happen more often than major earthquakes (any number of hurricanes, floods, tornadoes and fires come to mind), but outside of a few areas o f the country, hardly anyone is prepared for earthquakes.

The Great Southern California ShakeOut is a fantastic idea, but it needs to happen in other places than California. The Pacific Northwest, sitting on a subduction zone capable of producing 9+ magnitude earthquakes, is especially at risk, as well as the entire Midwest (which could experience another New Madrid quake) and even the East Coast (where Charleston was once the site of a ~7 magnitude quake). While the recurrence interval for quakes in the eastern US is certainly much longer than elsewhere, major quakes can - and do - happen. And when they do, very few people will be prepared in any way whatsoever. That's why the ShakeOut is a great opportunity for the entire country to get involved in an earthquake drill. Even if it's something as simple as securing heavy shelves to the wall (a good idea anyway), mapping out a route to get away from urban centers, putting together an emergency kit, or stocking up on bottled water and canned food, get involved!

Here's the info from the ShakeOut website:

"The Great Southern California ShakeOut is a week of special events featuring the largest earthquake drill in U.S. history, organized to inspire Southern Californians to get ready for big earthquakes, and to prevent disasters from becoming catastrophes. An Earthquake Drill for the Record Books

"At 10 a.m. on November 13, 2008, millions of southern Californians will “Drop, Cover, and Hold On.” Why? An enormous earthquake is in our future, and the ShakeOut Drill is our chance to practice what to do when it happens. Individuals, families, businesses, schools and organizations will join firefighters, police officers, and other emergency responders (involved in the statewide “Golden Guardian” exercise) in our largest-ever earthquake preparedness activity. Don’t miss out!

"ShakeOut is based on a potential 7.8 magnitude earthquake on the southern San Andreas Fault. This type of earthquake occurs in southern California every 150 years on average, and the last was 151 years ago! Dr. Lucy Jones of the U.S. Geological Survey has led a group of over 200 scientists, engineers, and others to study the likely consequences of this enormous earthquake in great detail.

"In summary, the ShakeOut Scenario estimates this earthquake will cause some 2,000 deaths, 50,000 injuries, $200 billion in damage and other losses, and severe, long-lasting disruption. The report has regional implications and is a dramatic call to action for preparedness, and is available at www.ShakeOut.org.

"The ShakeOut includes these main events:

• ShakeOut Drill (Nov. 13)
• International Earthquake Conference (Nov. 12-14: Presented by the City of Los Angeles - iec.lacity.org)
• Golden Guardian Emergency Response Exercise (Nov. 13-19: Emergency mangers, fire fighters, and other first responders will practice how they will respond to this large earthquake -
• Los Angeles Earthquake: Get Ready Rally (Nov. 14: designed by Art Center College of Design)
• Take One More Step (Nov. 14-16: community activities to promote additional preparedness.)"

("Shift Happens" makes a fantastic bumper sticker, by the way.)

We had an earthquake!

Okay, so 1.8 is pretty dinky - but I felt this one, darn it. Whee! My first earthquake.

Details from the Arlington Alert website:

05/06/08 14:55	The USGS has confirmed a magnitude 1.8 "micro" earthquake occurred near Annandale, VA at 1:30pm. There have been no reports of damage or injuries. OEM/LCS
05/06/08 14:31	The National Earthquake Information Center, via FEMA Operations, is reporting that Northern VA has experienced rumblings equivalent to an earthquake of magnitude 2 to 3. It remains unclear if this was an actual earthquake, or due to another cause. Arlington OEM will continue to monitor. OEM/LCS

The USGS report:

Earthquake Details

Magnitude	1.8
Date-Time	Tuesday, May 06, 2008 at 17:30:23 UTC Tuesday, May 06, 2008 at 01:30:23 PM at epicenter
Location	38.828°N, 77.234°W
Depth	10 km (6.2 miles) set by location program
Region	VIRGINIA
Distances	2 km (1 miles) WSW (250°) from Annandale, VA 3 km (2 miles) NW (320°) from North Springfield, VA 3 km (2 miles) SE (143°) from Mantua, VA 6 km (4 miles) NNE (32°) from Burke, VA 12 km (8 miles) WSW (242°) from Arlington, VA 21 km (13 miles) WSW (244°) from Washington, DC
Location Uncertainty	horizontal +/- 1.7 km (1.1 miles); depth fixed by location program
Parameters	NST= 6, Nph= 13, Dmin=70.2 km, Rmss=0.3 sec, Gp=151°, M-type=duration magnitude (Md), Version=1
Source	Lamont-Doherty Cooperative Seismographic Network (LCSN)
Event ID	ld1022071

Now I'm all excited. Yup, not getting any work done today.

(Actually, we thought someone was moving furniture upstairs. Or that our elevator had crashed. )

UPDATE: Oh, I feel cool. Got to do the "Did You Feel It?" report. Oh yeah.

UPDATE 2: Thanks to Ron for the email - he checked in with Callan and I right away. (Callan's got great coverage, and he managed to find the seismogram of the earthquake from the Maryland Geological Survey. And he was practically on top of the thing. Lucky!)

Here's one for Julian!

The USGS has released updated versions of their National Seismic Hazard Maps.

(Image from the 2008 USGS Fact Sheet)

And look! A green spot over western New York! That's way better than being in the blue. (Not as exciting as sitting on a subduction zone capable of generating M9+ earthquakes, but I suppose I can't have everything.)

Update: While poking around the USGS Urban Hazard Maps, I found this one of Seattle. All I can say is, wow. What did they build UW on, a giant sandbox? That wouldn't stop me wanting to go there later, but if they have a big earthquake and Johnson Hall collapses on me, it would be pretty hard to finish a Ph.D.

Why yes, I do have goals

G. K. Gilbert, in his account of the San Francisco Earthquake of 1906:

It is the natural and legitimate ambition of a properly constituted geologist to see a glacier, witness an eruption and feel an earthquake. The glacier is always ready, awaiting his visit; the eruption has a course to run, and alacrity is always needed to catch its more important phases; but the earthquake, unheralded and brief, may elude him through his entire lifetime."

I recently came across this quote in A Crack in the Edge of the World by Simon Winchester. What I found amusing (and cheering, in a way), is that in more than a hundred years, the field of geology hasn't changed so much that I can't look at this quote and say, "Aha! That's exactly how I feel!" Granted, the part about the glacier isn't quite true anymore, and the "his" and "him" reflect an age of the science when there were no women involved, but as for the rest of it - well, those are my sentiments exactly!

The part about the earthquake is especially relevant to me because I actually should have had the opportunity to feel several. One was the December 9, 2003 M4.5 that occurred in the Central Virginia Seismic Zone about 40 miles West of Richmond. I was a freshman at the time, and out caroling around campus with some friends. Unfortunately, being outside on the ground, this meant that I was unable to feel the quake, since the only people who noticed it in my area were on the upper floors of buildings (which apparently magnified the effects a bit). I was, needless to say, extremely unhappy to have missed feeling the most significant EQ in Virginia in decades. (There's a good writeup of that quake here.) The second time around was this past summer; I'd just come home from a month-long stay on the Big Island of Hawaii, only to find out that, ten days later, there was a M5.4 less than 10km RIGHT UNDER KILAUEA. That time, I was really pissed. I spent most of that month sitting on top of the volcano and nothing. But as soon as I left?

So you might say that I've been unlucky catching earthquakes. I have been lucky enough to visit Kilauea when the eruption was still feeding flows at the ocean entry, and it was then that I had my first real experience with hot lava (which got me permanently hooked on volcanology right then and there). The second Kilauea trip was somewhat less successful in locating the hot stuff; Pu'u O'o had recently begun the "Harry Potter" fissure eruption (July 21, 2007; they like to name the events after holidays or, if nothing else is available, book releases) and, despite a truly grueling hike out to the cone, we were only able to see the fissure source and not the active flows. (It was still hot out there, though, and we came pretty close to the flows before turning back because of safety concerns. Funny how a little thing like having to walk on partially-molten lava can ruin your hike.) I would really love to see a fountaining event, and my career goal is to work on stratovolcanoes, which means seeing a Pinatubo or St. Helens-style explosive eruption would basically make me incoherent with joy.

Glaciers...I've had even less luck with. I've seen plenty of glacier deposits, including some really spectacular moraines and cirques on the Fish Lake Plateau in Utah and striations on the slopes of Mauna Kea, but I have yet to see real glacial ice. Unfortunately, at the rate things are going climate-wise, if I don't go see some in the next ten years, there might not be much left. Certainly any dream of visiting the glaciers of Kilimanjaro is pretty much kaput at this point, and with the way the Alaska ones are retreating nowadays, I'd better book one of those Princess cruises pretty quick.