Most earthquakes occur when great stresses building up within the earth are suddenly released This sudden release of this stored energy causes movement of the earth’s crust along fractures, called faults, and generates shock waves. These shock waves, or seismic waves, radiate in all directions from the focus, much as ripples radiate outward in two dimensions when a pebble is dropped into a pond. Although most earthquakes are associated with movement along faults, they can also be triggered by volcanic activity, by large landslides, and by some types of human activity. However, in areas not known for frequent earthquakes, pinpointing the cause of the rare tremor can be very difficult.
Very little is known about the causes of earthquakes in the eastern United States. In general, there is no clear association among seismicity, geologic structure, and surface displacement, in contrast to a common association in the western U.S. The mid-Atlantic and central Appalachian region, including Maryland, is characterized by a moderate amount of low-level earthquake activity. In Maryland, there are numerous faults, but none is known or suspected to be active. Because of the relatively low seismic energy release, this region has received relatively little attention from earthquake seismologists (Bollinger).
In August, 2011 an earthquake in central Virginia jolted Baltimore and much of the East Coast. Thousands of people felt the quake and small pockets of the city experienced moderate damage. Data from the 2011 Virginia earthquake shows East Coast tremors can travel much farther and cause damage over larger areas than previously thought.
Based on current science and studies, Maryland has a very low chance of experiencing a damaging earthquake in a 50-year period. However, we should continue to plan ahead and be prepared for the chance of another earthquake impacting the area in the future.
Climate Sensitive Diseases
Changes in climate may enhance the spread of some diseases. Disease-causing agents, called pathogens, can be transmitted through food, water, and animals such as deer, birds, mice, and insects. Climate change could affect all of these transmitters.