Earthquakes are geological phenomena and thus, literally shake the earth irrespective of political borders. Yet the destruction of an earthquake can have far reaching political consequences to the United States or any nation that has to endure these natural disasters. Historically, earthquakes in North America predate the United States. However, since they are a part of our historical record and remain a viable threat to millions of Americans, a study of earthquakes in American history is a pertinent subject for high school students in United States History class. The study of earthquakes requires skills that students of history need to master. Reading or compiling data on maps, charts, and graphs is part of the Social Studies Curriculum. Moreover, examining the past as a means to prepare for the future essentially defines the rationale for any historical exploration. In this case, in the face of the devastating consequences posed by any potential earthquakes, there is much at stake for regions of the United States politically, economically, and socially. This unit will use the historical example of the New Madrid Earthquakes of 1811-1812 to expose students of high school history to the causes and effects of earthquakes. It should at the very least displace some common misconceptions about the nature of earthquakes in the United States.
Because the West Coast of the United States has experienced a number of infamous earthquakes, most Americans believe that earthquakes and their destructive forces occur primarily in California or on the Pacific Coast. Two of the most serious earthquakes in the history of the United States have helped shaped this popular perception. The San Francisco Earthquake of 1906 and the Good Friday Earthquake in Alaska in 1964 wrought havoc on the natural landscape and the built environment. More recently, the World Series Earthquake of 1989 reinforced the notion of California as "earthquake central". This seismic event was made famous by the fact that millions of people (including me) had their television sets tuned to the World Series game, between the Oakland A's and the San Francisco Giants, when an earthquake shook the ballpark along with the surrounding region. In the destruction caused by this quake, a section of elevated highway collapsed and killed a number of motorists. I remember watching the news reports of the game being disrupted and of the highway collapse. I could recall only once hearing of a tremor in the Northeast, so this televised event reinforced my wondering why anyone would want to live in a section of the country that could "fall into the ocean" at any time. Actually it is not due to ignorance that I haven't noticed an earthquake in Connecticut or the Northeast in my lifetime. Connecticut is one of only seven states that have not had an earthquake of magnitude 3.5 in the last 30 years (USGS, 2007, Regional Information-Last Earthquakes, Earthquakes Hazards Program). In contrast, Southern California has approximately 10,000 earthquakes per year. Several hundred are of magnitude 3.0 or higher (USGS, 2007, About Earthquakes- Earthquake Facts, Earthquakes Hazards Program). However, this does not mean that earthquakes only occur on the West Coast.
According to the United States Geological Survey, the largest earthquake in the history of the United States struck the Mississippi Valley Region, in the Midwestern United States, in the winter of 1811- 1812. Four major shocks of Modified Mercali intensity VI-VIII along with numerous and sizeable aftershocks appear to have originated from an epicenter below New Madrid Missouri, then a small frontier town along the Mississippi River between St Louis and Natchez Mississippi (USGS, 2006, Earthquake Center-Historic Earthquakes, Earthquakes Hazards Program ). Scientists, Arch Johnston and Eugene Schweig (1996), concluded that at least six and possibly nine major events struck at moment magnitude M>7 and at least two events were at least M>8 (Johnston, A and Schweig, E. 1996 p.1). Most striking is the fact the principal quakes not only severely affected the grounds above the epicenter but they also shook the earth in cities on the East Coast. Damage was reported as far away as Charleston, South Carolina and Washington D.C. In Boston, 1000 miles away from the epicenter, the shock was severe enough to ring a church bell (Schweig, E, Gomberg, J, and Hendley II, J, 1995). Log cabins and chimneys fell in Cincinnati, Ohio and the ground shook in Quebec, Canada (Stover,C, and Cover, J.1993).
Considering that earthquakes on the West Coast are felt rarely more than a few hundred miles from their epicenter, the New Madrid series of earthquakes are certainly significant
Unfortunately, the prevalence of more frequent and recent earthquake activity on the West Coast, coupled with the fact that no major earthquake of similar magnitude has occurred in the Midwest since the 1811-1812 events, has reinforced the notion of "earthquake central" on the West Coast while relegating the New Madrid events to a footnote in the national memory.
The severity of the New Madrid events should inspire a closer look at the geological profile of the United States and the history of seismic activity in the United States. Scientific investigations since the 1970's have brought to light that the New Madrid area rests on top of the most seismically active zone east of the Rocky Mountains (Schweig, E, Gomberg, J, and Hendley II, J, 1995). They reveal that earthquakes are a realistic natural disaster in the nation's interior and not only on the West Coast. The event raises questions about when, not if, a similar event or series of seismic events could occur again. Moreover it should raise concern as to whether or not similar events could occur in other regions of the country that escape being considered potential natural disaster sites. Study of the New Madrid Earthquakes of 1811-1812, as historical and geological events, should lead to a more comprehensive understanding of the geological profile of the United States. Subsequently, the unit will explore the history of earthquakes across the continental United States, the potential for future seismic events, and the implications for specific communities in areas subject to earthquakes.
Increased awareness of the history and potential threat of seismic activity in the United States can only help all of us. The cost of earthquakes in lives and dollars can be enormous. Approximately three-thousand people died in the San Francisco Earthquake of 1906 due to the earthquake and related fires. One hundred and twenty-five people died in the 1964 Alaska Earthquake from the earthquake and related tsunami. The earthquake killed 15 people in Alaska but the related tsunami killed 98 people in Alaska, 11 in California, and one person in Oregon. A 1946 earthquake unleashed a tsunami that killed 159 people in Hawaii, five in Alaska, and one person in California (USGS Earthquakes Hazards Program-Deaths from Earthquakes). The financial losses of earthquakes to the United States are projected to be approximately $4.4 billion annually. Los Angeles County has the highest projected losses at $1billion annually (Abbott 2006, p. 143).
Fortunately the United States has not suffered a devastating earthquake in the last decade. This has not been the case in other parts of the world. In December 2003, 41,000 people died and another 100,000 went homeless due to a strong quake that shook Iran (Abbott, 2006, p.4). Even more recently, an earthquake rocked Pakistan on October 8, 2005, killed at least 86,000 people, and wounded more than 69,000 people (USGS, 2006, Earthquake Center-Historic Earthquakes, Earthquakes Hazards Program).
Most earthquake casualties are due to construction that fails and collapses. Indeed, attention to how buildings are constructed in known earthquake zones can save much loss of life and destruction. Ignorance of or being unprepared for a natural disaster threat would be devastating. One has to look no farther than the examples of recent earthquakes in Iran and Pakistan cited above
Having students and adults in the United States acknowledge the potential dangers of earthquakes not only in the Pacific region but across the country is an important first step toward disaster preparedness.
New Madrid, Missouri is located more than a thousand miles from areas known for their earthquakes such as California and Alaska. Yet, between December 16, 1811 and March 15, 1812, an amateur seismologist named Jared Brooks reported 1,874 earthquakes (Abbott, 2006, p.157). Some of the quakes were of sufficient magnitude to reroute the Mississippi River, drown a forest, and form a new lake. How and why these events happened are essential questions I hope to answer in developing this unit. When these events occurred, New Madrid was a small frontier settlement that claimed to be the "Gateway to the West". The Louisiana Purchase was not even ten years old when these events occurred and the War of 1812 was but a few months away. The lack of development in this frontier area and the fact that this event happened in a bygone time shouldn't minimize the implications of these seismic events. Today, the region affected by the New Madrid quakes is well developed and populated. Moreover, the geological profile of the area prompts scientist to predict that future quakes there are probable. Important cities such as St. Louis and Memphis as well as other Mississippi Valley habitats would be very adversely affected.
Unlike the stereotypical 'West Coast quake' which occurs next to a plate-tectonic transform fault or subduction area, the New Madrid quakes occurred in a failed rift zone. I seek to explore with my students why this particular kind of quake can be just as dangerous or even more so than quakes that occur along known fault lines. Students should understand the principles that suggest that quakes on failed rift zones are felt over greater distances than those localized seismic events on known fault lines. Naturally this should lead students to compare various types of earthquakes that have occurred across the United States in the history of the United States. Essential questions for our study may include: How are the geological profile of a region and the probability of earthquakes related? How are the New Madrid earthquakes similar and different from other quakes in the history of the United States in regard to size, scale, location, and damage?