Maryland Geological Survey: IRIS Educational Series #2

Maryland Geological Survey	Maryland Seismic Network
IRIS Educational Materials

Education & Outreach Series No. 2

Why Do Earthquakes Happen?

    You probably associate earthquakes with destruction caused by falling buildings or by the creation of tidal waves.

    While earthquakes may be associated with destruction in the time frame of human activity, in the evolution of the Earth they signal the geological forces that build our mountains and create our oceans. In many ways, earthquakes are one of nature’s reminders that we are living on the thin outer crust of a planet whose interior is still cooling.

    Earthquakes happen when parts of Earth’s crust move. Big earthquakes occur with movement of about a meter or two. Small earthquakes happen with movements of millimeters.

On the maps below, each dot marks the locations of a magnitude 4 or larger earthquake. The earthquakes were recorded over a five year time period.

IRIS is a university research consortium dedicated to monitoring the Earth and exploring its interior through the collection and distribution of geophysical data.

IRIS programs contribute to scholarly research, education, earthquake hazard mitigation, and the verification of the Comprehensive Test Ban Treaty.

Support for IRIS comes from the National Science Foundation, other federal agencies, universities, and private foundations
   Earth’s outer surface in broken into what geologists call plates. Earthquakes occur when plates move under, over, or slide past each other. As you can see on the map below, most earthquakes occur along the edges of the large plates that make up Earth’s crust. The arrows on the map indicate how fast the plates are moving in millimeters per year - about as fast as your fingernails grow.

Click here to view the IRIS Seimic Monitor

This figure was produced in cooperation with the US Geological Survey, and Princeton University.

1200 New York Ave.,
NW #800
Washington DC 20005
phone (202)682-2220
fax (202) 682-2444
http://www.iris.edu

This educational material is reproduced with permission from the IRIS Consortium. This page was adapted for the web by Bob Conkwright , from an Adobe Acrobat PDF document created by the IRIS Consortium.

To obtain a copy of " Education & Outreach Series No. 2" in Adobe PDF format,
Click Here

To request preprinted copies of any or all of the Education & Outreach Series, please send your request to susan@iris.edu (please include the handout volume number and quantity needed for each).

updated 4/4/05

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	Education & Outreach Series	No. 2
	Why Do Earthquakes Happen?
	You probably associate earthquakes with destruction caused by falling buildings or by the creation of tidal waves. While earthquakes may be associated with destruction in the time frame of human activity, in the evolution of the Earth they signal the geological forces that build our mountains and create our oceans. In many ways, earthquakes are one of nature’s reminders that we are living on the thin outer crust of a planet whose interior is still cooling. Earthquakes happen when parts of Earth’s crust move. Big earthquakes occur with movement of about a meter or two. Small earthquakes happen with movements of millimeters. On the maps below, each dot marks the locations of a magnitude 4 or larger earthquake. The earthquakes were recorded over a five year time period.

IRIS is a university research consortium dedicated to monitoring the Earth and exploring its interior through the collection and distribution of geophysical data.

IRIS programs contribute to scholarly research, education, earthquake hazard mitigation, and the verification of the Comprehensive Test Ban Treaty.

Support for IRIS comes from the National Science Foundation, other federal agencies, universities, and private foundations	Earth’s outer surface in broken into what geologists call plates. Earthquakes occur when plates move under, over, or slide past each other. As you can see on the map below, most earthquakes occur along the edges of the large plates that make up Earth’s crust. The arrows on the map indicate how fast the plates are moving in millimeters per year - about as fast as your fingernails grow.

This figure was produced in cooperation with the US Geological Survey, and Princeton University.

1200 New York Ave., NW #800 Washington DC 20005 phone (202)682-2220 fax (202) 682-2444 http://www.iris.edu

This educational material is reproduced with permission from the IRIS Consortium. This page was adapted for the web by Bob Conkwright , from an Adobe Acrobat PDF document created by the IRIS Consortium.
To obtain a copy of " Education & Outreach Series No. 2" in Adobe PDF format, Click Here To request preprinted copies of any or all of the Education & Outreach Series, please send your request to susan@iris.edu (please include the handout volume number and quantity needed for each).
updated 4/4/05 \| Return to previous page \| Go to the IRIS One Pagers Home Page \|