U.S. Department of the Interior

U.S. Geological Survey Fact Sheet 2005-3026

March 2005

Printed on recycled paper

PAGER—Rapid Assessment and Notification 

of an Earthquake’s Impact 

PAGER (Prompt Assessment of Global Earthquakes for Response) is an automated alarm system 

being developed to rapidly and accurately assess the severity of damage caused by an earthquake and to provide emergency relief organizations, government agencies, and the media 

with an estimate of the societal impact from the potential catastrophe.

Responding to Global Earthquake Hazards

Photograph showing destruction caused by the 1999 Izmit, Turkey, earthquake. For events such as this, 

PAGER will provide emergency relief organizations with a rapid assessment of an earthquake’s impact that 

will allow them to determine which areas require the most attention.

Although the basic concept of PAGER 

is straightforward, the implementation 

will require significant system development, communication, and collaboration. 

The modular design of PAGER will allow 

the incorporation of more detailed datasets, new algorithms, and interactive tools, 

thereby improving the systems ability to 

rapidly assess an earthquake s impact.

PAGER is still in development but is 

progressing toward a fast, accurate system that international and domestic users 

can rely on. The PAGER team is continuously seeking collaboration with other 

agencies, both domestic and worldwide, 

to create a system that will benefit the 

populations of earthquake-stricken areas.

PAGER will distribute alarms via 

pager, mobile phone, and e-mail that 

will include a concise estimate of the 

earthquake s impact. The alarms will 

also report the earthquake location, 

magnitude, and depth, an estimate of the 

number of people exposed to varying 

levels of shaking, a description of the 

region s vulnerability, and a measure of 

confidence in the systems impact assessment. Associated maps of shaking level, 

population density, and susceptibility to 

landslides will be posted on the Internet. 

This information will be available within 

minutes of the determination of the earthquake s location and magnitude. 

At the heart of PAGER are the timely 

and accurate earthquake location and 

magnitude determinations that the 

USGS has been producing for decades. 

PAGER uses these earthquake parameters to calculate estimates of ground 

shaking by using the methodology and 

software developed for ShakeMap (http:

//earthquake.usgs.gov/shakemap/). The 

number of people exposed to various 

levels of shaking is then calculated by 

combining the maps of predicted ground 

shaking with Oak Ridge National Laboratory s Landscan2003 population database. 

Finally, PAGER generates an impact 

statement by considering the vulnerability 

of the exposed population and infrastructure, potential for earthquake-induced 

landslides, and, if available, damage 

reports from previous nearby historic 

earthquakes for comparison purposes and 

damage projection.

The U.S. Geological Survey s National Earthquake Information Center 

(NEIC), located in Golden, Colorado, 

reports over 30,000 earthquakes a year. 

Tragically, on average, 25 of these cause 

significant damage, injuries, or fatalities. 

The U.S. Geological Survey (USGS) 

often detects these damaging quakes well 

before eyewitness reports are available 

and must decide rapidly whether Federal 

and international agencies should be 

alerted to a potentially damaging event. 

Currently, the USGS relies primarily on 

the experience and intuition of the onduty seismologists to estimate the impact 

of an event. To improve the accuracy 

of this assessment and the content of 

the USGS earthquake alerts, the USGS 

is developing an automated system to 

immediately estimate an earthquake s 

impact on humans for events anywhere 

worldwide; this system will provide 

important information to help emergency 

relief organizations, government agencies, and the media plan their response to 

earthquake disasters.
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1 After the magnitude and hypocenter of an earthquake are determined, an estimate of the resulting ground shaking is obtained 

by using ShakeMap methodology. This color-coded example is from 

the February 2004, magnitude 6.4, Al Hoceima, Morocco, earthquake.

2 The population of the affected region is obtained from the Landscan2003 global population database developed at 

Oak Ridge National Laboratory.

3 By combining the map of predicted shaking with the population, PAGER obtains an estimate of the number of people exposed to 

different levels of shaking.

4 By using the population exposure and the vulnerability of the local infrastructure, PAGER will determine the potential scope of the catastrophe 

and issue alarms to emergency relief organizations, government agencies, 

and the media. PAGER is an interactive system. As subsequent information 

becomes available, more accurate maps of ground shaking are produced, and 

updated alarms are issued, if necessary.

For More Information:

Earthquake Hazards Program

U.S. Geological Survey

Golden, CO 80401

http://earthquake.usgs.gov/

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Written by Paul S. Earle, David J. Wald, and 

 Lynda A. Lastowka

Graphics and Layout Design by Eleanor M. Omdahl 

This Fact Sheet is available online at 

http://pubs.usgs.gov/fs/2005/3026/

The PAGER Process

The following steps are involved in estimating an earthquake’s impact: