People generally did the wrong thing during the quake – many ran outside, even though FEMA recommends that people who are inside a building stay where they are , drop, take cover, and stay away from windows and other glass (http://www.fema.gov/hazard/earthquake/eq_during.shtm). Even the US Geological Survey office in Reston, Virginia was evacuated!

On the West Coast, where I happened to be during the quake (in Seattle), people in general (and news anchors in particular) took great pleasure in comparing the Virginia quake to others of similar magnitude that happen much more frequently in the seismically active Northwest. Lots of ribbing and mocking – mostly good natured – took place in the days that followed the quake.

East Coast earthquakes are much less common than West Coast earthquakes, because the eastern edge of the United States is what is called a passive continental margin. It is the edge of a continent (North America), but it is not the edge of a plate, and the edges of plates are where most seismic activity tends to occur. The edge of the plate on which the North American continent is riding is in the middle of the Atlantic Ocean, at the Mid-Atlantic Rift. That is where the North American Plate is moving apart from the Eurasian Plate (and, further to the south, the African Plate); earthquakes (and volcanic activity, as well) do indeed occur along that rift boundary.

Actually, East Coast earthquakes happen all the time; they’re just usually not this powerful. The August 23 quake was the strongest ever measured in Virginia. The causes of many of these intraplate earthquakes are not thoroughly understood. Some involve the activation of old, deep-seated faults. The area in which this particular quake occurred, the Central Virginia Seismic Zone, had experienced seismic activity before, but not along known, measured faults. The largest known historic earthquake in this area was a bit father to the west, in 1875, and was likely a bit less powerful than the 2011 quake. 

One geophysicist explained the cause of intraplate earthquakes like this: Imagine a plate the size of North America that is being jostled around on all sides by interactions with other plates. Obviously most of the earthquake activity will take place around the edges, but you’re also bound to be building up some stresses in the middle of the plate, too, which will eventually cause earthquakes to occur in the middle of the plate.

The details of the 2011 and historic quakes in the Central Virginia Seismic Zone can be found at the USGS Earthquake Hazards website (http://earthquake.usgs.gov/) . This is a truly rich resource that you should check out, if you haven’t already.

Of real concern is the lack of earthquake preparedness in the East. The general panic and uncertainty about what to do highlights this lack of preparedness. Another aspect is the general state of earthquake resistance of buildings in the East. Many older buildings are actually better suited to survive earthquake shaking than modern high-rises, which – unless specifically engineered to be earthquake-resistant, as they are typically now on the West Coast – are more likely to be rigid and subject to failure during seismic shaking. An interesting site with much information about cutting-edge research on earthquake engineering, damage assessment, and architecture is the Consortium of Universities for Research in Earthquake Engineering (http://www.curee.org/).

An additional educational resource that is worth checking out is Teachable Moments, provided by the University of Portland and IRIS Education and Outreach (IRIS is Incorporated Research Institutions for Seismology). You can find a Teachable Moment about the August 23 Virginia earthquake at http://www.iris.edu/hq/retm, and you can sign up to be on the Teachable Moments list-serv at the IRIS website (http://www.iris.edu/hq/programs/education_and_outreach/).

 Barbara Murck

Have a look at the video at:

http://www.youtube.com/watch?v=1fDDhp4DWgU&feature=related

I can be followed on twitter at: www.twitter.com/ArbogastDPG

Posted by: Alan Arbogast, Michigan State University

The active nature of the Pacific Ring of fire was observed again today (Friday, 3/11/11) when a magnitude 8.9 earthquake rocked Japan. The epicenter for this earthquake was located offshore, approximately 230 miles northeast of Tokyo. This earthquake is the strongest in recorded Japanese history and aftershocks continue, the strongest of which were magnitude 7.1. In addition to the destruction caused by the earthquake itself, a massive tsunami was generated that crashed into the shore of Japan. The highest wave associated with this surge was measured at 30 feet. In a manner very consistent with the 2004 tsunami, surging water along the coast of Japan devastated coastal communities and spread with incredible power as far as 6 miles inland. Many scores of people likely perished in the disaster and the extent of loss is currently undetermined.

Although the tsunami is certainly a catastrophic disaster in Japan, this situation demonstrates the benefits of the tsunami warning system that was installed in the Pacific Ocean basin in 1949. As a result of the system, a tsunami warning was rapidly given and no doubt saved some lives in Japan. A warning was also generated for Hawaii, in the middle of the Pacific Ocean, and the West Coast of the United States. Coastal communities in these locations thus had ample time to prepare and move people out of potential danger. In stark contrast, no such warning system existed in the Indian Ocean basin at the time of the Indonesian earthquake. As a result, people in coastal communities far away from the earthquake epicenter were unaware of the approaching tsunami and over 250,000 deaths occurred. This contrast demonstrates why it is necessary to understand natural hazards and plan effectively for them.

Submitted by: Alan Arbogast, Michigan State University

By 10pm we learned that the alert in Hawaii was upgraded from “Tsunami watch” to “Tsunami warning” and we started packing a cooler with ice, food and water. Searching the web I found that the Pacific Tsunami Warning Center models predicted a 2m wave…ok, significant, but not catastrophic.

I live on Kailua Beach, Oahu and have obvious exposure to coastal hazards such as this: http://ptwc.weather.gov/ but I figured at worst the water would crest the dune, and roll into the yard but not cause serious damage where I live…I considered not evacuating, but decided against that.

By 11pm the sirens started, and by midnight the evacuation was in full swing. Police cars and firetrucks drove through the neighborhood blaring horns and broadcasting the message “This is State Civil Defense. A tsunami is approaching. Please evacuate to higher ground now.” Every house in the neighborhood was alight and bustling with activity. We tried grabbing a few hours sleep before the predicted arrival time of 3:20AM – but this was hard with all the noise in the street.

Our family friends the Luis’s, living a mile away offered their home to us and by 2AM we were on their floor trying to get to sleep between blaring emergency sirens every 30 minutes. I woke at 5am, and we drove back home.

The roadblocks were gone and the usual early morning commute was absent…totally empty streets. A quick trip to the beach in front of our home revealed that indeed a wave had washed up and crested the dune and stalled there – but the power of this wave was revealed in how flat and planned off the beach profile looked; no foreshore, no berm crest, no sub aerial beach, just a flat gentle slope rising out of the water….and incredible amount of sand must have been eroded.

As I write this we are still under tsunami warning, and in a similar event in the 1930′s from the same part of Japan, the worst damage in Hawaii was caused by the tenth wave. so it may be awhile before this is over.

Submitted By Chip Fletcher, University of Hawai’i

"In volcanically active regions, hydrothermal features are produced as groundwater is heated by contact with hot rock or magma below the surface. This hot water rises to the surface to produce a variety of features, including geysers, hot springs, mud pots, and fumaroles. Minerals dissolved in the water are deposited on the surface, producing a colorful if somewhat barren landscape. Iceland, located on the Mid Atlantic Ridge, has a wide variety of hydrothermal landscape. Sustainable geothermal sources provide well over 50% of the energy needs for this country of approximately 300,000 people." Gregory Bohr

The Icelandic landscape is one of the most unique and interesting on Earth.  One of the few land-based rift zones, it is a standard discussion in any Physical Geography or Geology course.  Geothermal features are not only observed and studied, but they are harnessed for energy.  These geothermal features have also proved a “harsh reminder” for the power of the Earth, as discussed in the post, Geography Directions: Eyjafjallajökull: Geography’s Harsh Reminder. The March 2010 eruption of the Eyjafjallajökull volcano had upset the operation of transportation and economic networks that bridged the Atlantic.  The costs, in time and money, were staggering.  Even more unnerving is the nature of such a geologic event, as it was virtually impossible to predict and to mitigate.

The eruption of Iceland’s Eyjafjallajökull on 20 March 2010 caught Europe dangerously off-guard. For two months, waves of ash closed some of the world’s busiest airspace. An estimated ten million passengers were left stranded, international train services collapsed under the heightened strain of people seeking alternate transportation, and governments were left to deal with angered airlines seeking to regain some portion of lost revenue. In total, over one hundred thousand flights were cancelled. The legal and political fallout of Eyjafjallajökull’s eruption continues today. A fundamental questions lies at the heart of this debate: why wasn’t Europe better warned or prepared? Amy R Donovan and Clive Oppenheimer (University of Cambridge) highlighted this problem in their March 2011 Geographical Journal commentary. The danger such natural events as Eyjafjallajökull pose, as Donovan and Oppenheimer argue, is that they lie outside the traditional realm of managerial governance.

Many natural events, however dangerous, lend governments two favours: first, relatively ample warning; second, comparatively localised impact. Hurricanes are an excellent case-in-point. Every summer NOAA, the United States’s oceanographic and atmospheric monitoring agency, continuously tracks existing storms and recalculates their future projectories. Excepting such hurricanes as Andrew and Katrina–most hurricanes cause damage across a limited geographic expanse before weakening significantly in strength. The snowstorms that rack the American northeast are similarly tracked in advance so that appropriate precautions can be taken (even if, in the event, those precautions prove inadequate).

The Eyjafjallajökull eruption, much like the 2004 Boxing Day tsunami and the 2010 Haiti earthquake, presents a very different scenario. Such events are difficult to forecast, even more difficult to contain, and–like other natural events–impossible to prevent. But, as The Geographical Journal commentary noted, preventative steps could have been taken. Although the Met Office’sVolcanic Ash Advisory Centre (VAAC), clearly noted the airspace risks posed by Iceland’s Eyjafjallajökull and Mýrdalsjökull volcanoes, this information was not included in the annual National Risk Register, nor did it predicate the implementation of ‘sophisticated, integrated UK or EU policy in advance of the recent volcanic activity’ (p. 2). One hopes that the Eyjafjallajökull airspace fiasco will serve as a reminder of our inability to tame the extremes of physical geography.

By Benjamin Sacks

To view the original article please visit the Geography Directions Blog.

To download and take the tour go to http://earthquake.usgs.gov/ and click on the ”Google Earth KML” link.

 Fletcher WileyPLUS Demo

Author William Least Heat-Moon describes an unusual transect from New York City to Astoria, Washington in his book River Horse: The Logbook of a Boat Across America. In it, he describes what seems at first an impossible transect — crossing the United States on fresh water in a 22-foot boat. Better known for his book Blue Highways, in River Horse he finds a way of crossing the country that avoids not only the major highways, but the minor ones as well. Most houses and businesses face a road, with a “front” maintained for visitors and passersby to see. By crossing the country on rivers and canals, Heat-Moon experiences the cultural landscape from behind the usual lines.

It is, of course, not physically possible to cross the United States entirely on fresh water, as several drainage divides must be crossed. Heat-Moon minimized the inevitable portages  by carefully mapping his route, by having friends occasionally swap a canoe for the main expedition craft, and by pushing each boat to the limits of its hull draft.

My wife Pamela (librarian, blogger, and honorary geographer) and I are planning a major transect of our own, assuming that the passenger automobile is still in use when we near retirement. To celebrate our 66th year, we are going to make a transect “from Chicago to L.A., more than two thousand miles all the way. ” That is, we are planning a transect along the old Route 66, which predates the Eisenhower Interstate Highway System by a generation. In many places, the original roadbed has been obliterated by the new system, but in others, it runs parallel — or it runs into the trees and fields. In many cases, travel facilities or entire small towns that served the original highway passengers have been abandoned.

I was put in mind of these various transects when I heard recently about a most unusual transect that geologist Robert Thorson and his wife Kristine followed in the summer of 2009. The transect is unusual in that they proceeded in an orderly fashion from east to west, but rather than following lines or curves, they followed a discontinuous collection of points on the landscape: the kettle ponds left by the receding ice of the Pleistocene glaciations. Their journey is documented in his book Beyond Walden: The Hidden History of America’s Kettle Lakes and Ponds and on his blog, Walden to Wobegon. The blog title refers to two kettle ponds made famous by literature: Thoreua’s very real Walden Pond and Garrison Keilor’s fictional Lake Wobegon. I learned about both the book and the blog from Robin Young’s delightful interview with Professor Thorson on WBUR’s Here and Now radio program.

Thorson provides insights regarding limnology, the ponds and lakes themselves, and the history of recreation on fresh water. In moving across the inverted archipelago at  the southern fringes of continental glaciation, however, he also tells tales of the land and the people in the vast spaces between those most intriguing bodies of water.

A final example of a transect comes from WBUR, one of  several public radio stations in Boston, Massachusetts. Traveling west from Boston along Route 9, WBUR produced programs in each of five cities and towns over the course of a week. On topics ranging from immigration to higher-education funding and arts-centered economic development, the series — aired as Finding a Way Along Route 9 — provides an excellent sampling of the current state of the economy and society in Massachusetts. Although the series does not cover the entire state, it makes a conscious effort to overcome a pervasive tendency to associate Boston — the primate city of Massachusetts — with the state as a whole.

Discussion / Activity

1. What are some examples of transects you have read about or encountered in radio, film, or other media? What did the traveler or travelers involved learn from their experience?

2. What is a transect that you could take in a single day, close to home, in order to learn something about your region? What mode of transportation would you choose, and what are its advantages and limitations? How would you record your learning along this transect? (This question can be treated either as a thought experiment or as an actual class assignment, in which each student plans a transect, follows it, and reports back. A group of students could be sent on transects that cover different “slices” of the same region.)

3. What is a transect that you would like to follow elsewhere in the world, if time and money were unlimited? What would you expect to learn?

http://edcommunity.esri.com/arclessons/lesson.cfm?id=536

This tutorial provides a quick and easy introduction to ArcGIS Explorer Online (AGX). Using the Gulf Oil Spill as the presentation topic, students learn to build an AGXOnline project by adding a base layer, adding content to the map (layers, points, and hyperlinks), and by capturing and editing slides into a classroom presentation.