This morning we wrote about hurricanes, and then Washington, D.C., had an earthquake.

The Federal Emergency Management Agency (FEMA) provides information about what to do before, during, and after an earthquake. FEMA also provides an index with contact information on state agencies.

As residents of the East Coast found out today, earthquakes can happen anywhere.

Earthquakes result from shifts in tectonic plates that comprise the Earth’s surface. The edges of the plates impact one another, creating intense geologic activity, including earthquakes, violent fracturing of the earth’s crust. There are also “intraplate” fault lines inside a tectonic plate where fracturing can produce similar results. The seismic waves or vibrations that result can create intense shaking on the Earth’s surface. The intensity of an earthquake is measured by the Richter scale.

An earthquake measuring 2 on the Richter scale can usually be felt by people standing on the ground. Five is considered moderate. Earthquakes of 6 (today’s quake with epicenter in Virginia is reported to be about 6, but so far we have not heard reports of major damage) or more are usually are considered severe and, depending on the location, can result in significant damage and disruption. Major earthquakes are often followed by aftershocks, a smaller earthquake that follows a larger one. While they may register lower on the Richter scale, when they follow a major quake, aftershocks can inflict severe damage.

While earthquakes are usually considered a West Coast problem (particularly in California and Alaska), they in fact pose a moderate to high risk to the majority of U.S. states. For example, the New Madrid fault line is a zone of significant seismic activity that crosses several midwestern and southern states. The results of a major earthquake, depending on intensity, could affect a particular locale or span several states. Imminent earthquakes cannot be accurately predicted.

Earthquakes are significant for the primary and secondary effects they produce. The initial concern is death and injury from structural collapse and flying debris. Secondary concerns can be wide ranging due to the disruption of infrastructure, which can cause anything from hazardous material releases at chemical facilities to the loss of electrical power and disruption of transportation. Further physical threats may also appear, such as additional structure collapse of buildings or bridges or flooding from damaged levees or dams.

For a major earthquake initial responses will be concerned with physical injury, fire fighting, and hazardous material incident response. Ensuring public safety and restoring infrastructure will also be early priorities. Shelter, food, and water for displaced persons and communities will be needed where the flow of goods and services cannot be quickly restored. Virtually every category of local emergency responder will be required. In addition, urban search and rescue teams, especially trained to deal with emergency response during structural collapse incidents, will be important. The National Guard is frequently called out for earthquake response missions. Federal support is contingent upon the severity of the incident. Disaster medical assistance teams are mobilized for larger incidents.

We got a big scare in D.C. today—it was scary enough. Scary enough to remind us that we ought to be better prepared for really big disasters. Today, Heritage released Homeland Security 4.0. One of the key findings of the report is that FEMA has been increasingly distracted from preparing for large-scale disasters like Category 4 hurricanes.

Heritage homeland security expert Matt Mayer points out that FEMA “has been responding to almost any natural disaster around the country, be it a contained three-county flood, or a catastrophe of near-epic proportions like Hurricane Katrina. As a result, many states and localities have trimmed their own emergency-response budgets, often leaving them ill prepared to handle even rain- or snowstorms without federal assistance. This leaves FEMA stretched far too thin and ill prepared to respond to grand-scale catastrophes.”

For more information, please see the Heritage report on lessons learned from the recent earthquake and Tsunami in Japan.