U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2007–3086

October 2007

What is ShakeCast?

ShakeCast, short for ShakeMap Broadcast, is a fully automated system for delivering specific ShakeMap products to 

critical users and for triggering established post-earthquake 

response protocols. ShakeMap is a well-established tool used to 

portray the extent of potentially damaging shaking following an 

earthquake. ShakeMap is automatically generated for small and 

large earthquakes in areas where it is available and can be found 

on the Internet at http://earthquake.usgs.gov/shakemap/. It was 

developed and is used primarily for emergency response, loss 

estimation, and public information. However, for an informed 

response to a serious earthquake, critical users must go beyond 

just looking at ShakeMap, and understand the likely extent and 

severity of impact on the facilities for which they are responsible. To this end the U.S. Geological Survey (USGS) has 

developed ShakeCast.

ShakeCast allows utilities, transportation agencies, businesses, and other large organizations to control and optimize the 

earthquake information they receive. With ShakeCast, they can 

automatically determine the shaking value at their facilities, set 

thresholds for notification of damage states for each facility, and 

then automatically notify (by pager, cell phone, or email) specified operators and inspectors within their organizations who are 

responsible for those particular facilities so they can set priorities for response. 

Example Uses and Users: The California Department of Transportation (Caltrans)

Caltrans has deployed the prototype ShakeCast system (Version 1.0). Following a major earthquake, Caltrans faces 

an array of decisionmaking challenges. Perhaps no other agency has a comparable earthquake exposure in the State 

of California. Caltrans has more than 11,000 bridges and overpasses under its responsibility in California; having an 

instantaneous snapshot of the likely damage to each will allow Caltrans to set priorities for traffic rerouting, closures, 

and inspections following a damaging earthquake. One of several critical tasks facing Caltrans after an earthquake is 

to rapidly assess the condition of all bridges and roadway corridors in the State highway system. Timely response is 

important to ensure public safety, aid routing of emergency vehicle traffic, and (re-) establish critical lifeline routes.

USGS ShakeCast

Automating, Simplifying, and Improving the Use of 

ShakeMap for Post-Earthquake Decisionmaking 

and Response

ShakeCast is a freely available, post-earthquake situational awareness application that automatically retrieves earthquake shaking data from ShakeMap, 

compares intensity measures against users’ facilities, and 

generates potential damage assessment notifications, facility 

damage maps, and other Web-based products for emergency 

managers and responders.

Collapse of the Interstate-5/State Highway-14 interchange showing damage north of Los Angeles caused by the 1994 magnitude 6.7 

Northridge, California, earthquake. Thousands of State and County 

bridges were shaken at varying intensity levels during this earthquake; 

many required inspections.

Printed on recycled paper
-119 ̊ -118 ̊ -117 ̊ -116 ̊ -115 ̊

32.5 ̊

33 ̊

33.5 ̊

34 ̊

34.5 ̊

35 ̊

Los Angeles

San Diego

Long Beach

Oceanside

Santa Clarita

Lancaster

Temecula

Indio

Brawley

Barstow

n

Mojave

Scenario ShakeMap: Southern San Andreas Fault

Scenario Date: Thu Nov 8, 2008 10:00:00 AM PDT M 7.8 N33.92 W116.47 Depth: 10.0km

PLANNING SCENARIO ONLY -- Map Version 1 Processed Thu Feb 8, 2007 11:47:37 AM PST 

INSTRUMENTAL 

INTENSITY

PEAK VEL.(cm/s)

PEAK ACC.(%g)

POTENTIAL 

DAMAGE

PERCEIVED 

SHAKING

I II-III IV V VI VII VIII IX X+

<0. 1 0.1-1.1 1.1-3.4 3.4-8.1 8.1-16 16-31 31-60 60-116 >116

<.17 .17-1. 4 1.4-3. 9 3.9-9. 2 9.2-18 18-34 34-65 65-124 >124

none none none Very light Light Moderate Moderate/Heavy Heavy Very Heavy

Not felt Weak Light Moderate Strong Very strong Severe Violent Extreme

-119 ̊ -118 ̊ -117 ̊ -116 ̊ -115 ̊

32.5 ̊

33 ̊

33.5 ̊

34 ̊

34.5 ̊

35 ̊

0 50

km

Fort Irwi

In addition to real-time notification, ShakeCast also can 

generate and deliver scenario earthquakes for facility response 

plans (figs. 1 and 2). This application includes routine testing 

of the system, earthquake scenario exercises, and evaluating 

performance and response under potential earthquake conditions. 

ShakeMap is now used routinely to generate earthquake scenarios 

for many regions; ShakeCast will further allow planning exercises 

to be performed using the same notification tools that will be 

available and in place for responding to a real earthquake. 

ShakeCast Technology

Individuals, companies, utilities, and agencies could develop 

their own strategies and tools for using ShakeMap given their 

Figure 1. ShakeMap intensity map for a magnitude 7.8 Scenario Earthquake on the southern San Andreas fault. Red lines delineate faults and light 

grey lines show highways.
DAMAGE UNLIKELY DAMAGE POSSIBLE DAMAGE LIKELY EXTREME DAMAGE POSSIBLE

Figure 2. The ShakeCast Users’ 

interface summary page in mapping 

mode. The unique features in the 

mapping mode include variable image 

size, selectable facility type, customizable facility icons, and color-coding 

to show possible damage. 
unique facilities and communication paths. However, such 

efforts are costly and complex. Rather, the USGS is facilitating this process with ShakeCast, building a more general-use 

tool for the most critical user needs. The ShakeCast software is 

customizable for facilities, fragilities, and notifications, and we 

anticipate additional adaptations will be made since the opensource code is provided. Such innovations then can be provided 

in the tool kit included with updates of the ShakeCast system.

Information Technology (IT) security is a primary concern 

for users requiring automatic electronic delivery of information. 

By taking advantage of standard Internet protocols, ShakeCast 

users avoid most typical corporate and Government concerns 

and firewall limitations. By using Really Simply Syndication 

(RSS) and interval polling, users initiate all communications 

with the USGS Web servers that host ShakeMap, and retrieve 

selected products as a request rather than a “push.” This RSS 

approach allows users to update software automatically under 

conditions of their own choosing. 

ShakeCast software is built upon open-source tools, providing standard, freely available software for all users, encouraging 

user improvements, and simplifying interfacing with existing 

users’ response tools. ShakeCast uses the Apache Web server 

and PHP (Hypertext Preprocessor) for dynamic Web content, 

MySQL for facility and notification databases, and is wrapped 

in Practical Extraction and Report Language (PERL) scripting. 

Exchange files are in Extensible Markup Language (XML) for 

standardized interfacing with Web, geographic information system (GIS), spreadsheets, databases, and other applications. 

Where Can ShakeCast be Used?

ShakeMap is now produced for all earthquakes around the 

globe of magnitude 5.5 or larger. Globally, these ShakeMaps are 

primarily predictive and thus lack the resolution and certainty 

of shaking estimates for maps made in regions of dense seismic 

instrumentation for which it was principally developed. Regions 

in the United States that have ShakeMap operating with reasonable (but variable) seismic station coverage include major parts 

of California, Washington, Oregon, Nevada, Utah, Hawaii, and 

Alaska. Other regions are improving station coverage. Hence, 

since ShakeMaps are produced for any region of the world, 

ShakeCast can be deployed for any exposure of facilities worldwide, again with more uncertainty in the results in regions not 

specifically listed above. 

We use the term “facilities” loosely; at the USGS National 

Earthquake Information Center (NEIC) in Golden, Colorado, 

we assign cities as “facilities” and run ShakeCast to determine 

shaking levels at cities within the United States and around the 

globe any time a ShakeMap is produced. The list of cities, their 

populations, and the intensity estimated at each city becomes 

a Hypertext Markup Language (HTML) email notification 

that proves useful for NEIC analysts and for other response 

purposes. Ultimately, these city-based notifications will be 

integrated as an option in the USGS Earthquake Notification 

Service (ENS), but this option does not reduce the need for critical users to put their own inventories into an in-house ShakeCast system.

ShakeCast Availability and Installation

ShakeCast is available in two levels, full and “Lite.” We 

describe in detail the full ShakeCast system that allows users 

to estimate impact to numerous facilities, each potentially with 

different vulnerabilities and notification recipients. We expect 

this system to be deployed by critical users in an earthquakehardened, operational environment. We have also made available 

ShakeCast Lite, a subset of the system that allows users to automatically receive ShakeMap products on their laptop or desktop 

computers, and launch predefined applications using those maps 

or data. For example, many users employ ShakeCast Lite to 

automatically open a Web browser showing the latest ShakeMap 

in their region, launch Google Earth® with the ShakeMap KML 

file, download ShakeMap grid files, and initiate loss-estimation 

applications, or deliver ShakeMap GIS files to their corporate 

GIS department for further analyses. ShakeCast Lite is simple to 

install and use.

An overview of ShakeCast from the users’ perspective is 

provided in figure 3. Organizations using ShakeMap/ShakeCast 

first download and install the ShakeCast (Version 2) software 

package on a hardened in-house computer system. The software 

is installed with an interactive installation script. Facility, vulnerability, and notification data are input using import tools and 

simple, comma separated (CSV) users’ files. ShakeCast comes 

preconfigured, but custom configuration is simplified by ShakeCast tools and the Web interface. The Web interface allows an 

administrator to access all functions of the local ShakeCast 

system, and end users are able to manage their own personal 

information and notification preferences.

Initial setup involves the following steps: (1) populating a 

database of facility locations and types; (2) assigning fragilities 

using specific ShakeMap parameters (for example, intensity, 

peak or spectral acceleration) and the corresponding likely 

“green,” “yellow,” and “red” damage states (“damage unlikely,” 

“damage possible,” and “damage likely” thresholds, for 

example); (3) specifying who receives notifications by listing 

Example Uses and Users: Los Angeles Unified School District (LAUSD)

LAUSD is using Shakecast to help improve earthquake monitoring and emergency response in southern California, 

where it is responsible for over 700,000 K-12 students, 100,000 employees, 13,500 buildings, and 1,100 schools and 

offices. Students and schools are spread across 704 square miles. Under an agreement with the City of Los Angeles, 

LAUSD buildings are integral to the emergency operations of the city, because school facilities will serve as emergency 

shelters to be managed by the Red Cross. Hence, knowing which structures are most likely damaged is critical for 

response and recovery, for example, in designating emergency shelters.
Provide Updates for Post-Earthquake Response

Check the Damage Assessment Estimate

Automatically Receive the Earthquake Notification

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facilities into categories for improved navigation and 

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and message formats

addresses of facility managers and response personnel (email, 

cell phone); and (4) selecting under which circumstances the 

alerts are sent (for example, damage “possible” at specific 

facilities). In addition, the user can customize the content of the 

summary report that is delivered internally; for example, a list 

of facilities based on their likely damage state, and organizational specific links and images.

Example user and earthquake data, tutorials, and documentation are provided with the installation package.

Ongoing ShakeCast Development

Ongoing software development of ShakeCast continues, and 

much of it is motivated by users’ experiences and recommendations. 

Figure 3. ShakeCast overview from the users’ perspective. 

ShakeCast, Release Version 2.1, is expected to include the following 

enhancements:

•	 Additional predefined facility structure types and vulnerability functions. Currently (2007) 36 structure types are available from the Federal Emergency Management Agency’s 

Hazards US loss modeling software (HAZUS-MH). 

•	 Additional vulnerability types, including pipeline, liquefaction, 

and landslide failure potential. In addition to maps, 2-D profiles 

will provide pipeline cross-sectional views.

•	 Ability to select a specific structure and seismic instrument data 

over interpolated shaking values from ShakeMap.
Sources of Additional Information 

On the Web:

ShakeMap: 

http://earthquake.usgs.gov/shakemap/

ShakeCast Software: 

http://earthquake.usgs.gov/shakecast/

Contacts:

Kuo-Wan Lin, USGS, Golden, CO, 

klin@usgs.gov, (303) 273-8563

David Wald, USGS, Golden, CO, 

wald@usgs.gov, (303) 273-8441

Acknowledgments

USGS contracted with Gatekeeper 

Systems, Inc., Pasadena, California, to 

help develop the prototype ShakeCast 

system (Version 1.0). Earlier funding for 

ShakeCast was provided by the American 

Lifelines Alliance (ALA), and it is now 

supported by the U.S. Geological Survey 

under the Advanced National Seismic 

System (ANSS). Motivation and support for the development of Version 2 of 

ShakeCast was provided by the California 

Department of Transportation (Caltrans) 

under the coordination efforts of Loren 

Turner.

Any use of trade, product, or firm names is for descriptive 

purposes only and does not imply endorsement by the U.S. 

Government.

•	 Expanded GIS support for common data 

exchange formats and application programming 

interfaces (APIs) (currently supports data export 

via user-defined templates).

•	Support for UNIX, Mac, and LINUX operating 

systems (currently runs on Microsoft Windows).

•	Compute and visualize uncertainties in ground 

shaking and damage likelihood.

•	Improved re-notification logic, allowing 

flexibility in conditions for re-alerting (for 

example, if damage state changes for one or 

more facilities).

Optional, automatic updates of the software 

will be provided by the RSS feed from USGS 

Web servers.

Collapsed section of the Cypress viaduct of Interstate 880 in Oakland following the magnitude 

6.9 earthquake in 1989 in Loma Prieta, California.