U.S. Department of the Interior

U.S. Geological Survey

Circular 1429

Version 1.1, July 2017

Advanced National Seismic System

Current Status, Development Opportunities, and Priorities for

2017–2027

Circular 1429

Version 1.1, July 2017

U.S. Department of the Interior

U.S. Geological Survey

By U.S. Geological Survey

Advanced National Seismic System

Current Status, Development Opportunities, and Priorities for

2017–2027
U.S. Department of the Interior

RYAN K. ZINKE, Secretary

U.S. Geological Survey

William H. Werkheiser, Acting Director

U.S. Geological Survey, Reston, Virginia

First release: 2017

Revised: July 2017 (ver. 1.1), online and in print

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Suggested citation:

U.S. Geological Survey, 2017, Advanced National Seismic System—Current status, development opportunities, 

and priorities for 2017–2027 (ver.1.1, July 2017): U.S. Geological Survey Circular 1429, 32 p.,

https://doi.org/10.3133/cir1429.

Library of Congress Cataloging-in-Publication Data:

Names: Geological Survey (U.S.), author.

Title: Advanced National Seismic System--current status, development

 opportunities, and priorities for 2017-2027 / by U.S. Geological Survey.

Other titles: U.S. Geological Survey circular ; 1429. 1067-084X

Description: Reston, Virginia : U.S. Geological Survey, 2017. | Series:

 Circular, ISSN 1067-084X ; 1429 | Includes bibliographical references.

Identifiers: LCCN 2017021417| ISBN 9781411341364 | ISBN 1411341368

Subjects: LCSH: Advanced National Seismic System (U.S.) | Seismic

 networks--United States.

Classification: LCC QE540.U6 G46 2017 | DDC 551.2028/7--dc23 | SUDOC I

 19.4/2:1429

LC record available at https://lccn.loc.gov/2017021417

ISSN 1067-084X (print) 

ISSN 2330-5703 (online)

ISBN 978-1-4113-4136-4
Preface

This Circular presents an updated strategic plan for the U.S. Geological Survey-led 

Advanced National Seismic System (ANSS). It was produced at the request of the 

ANSS National Steering Committee with input from all of those who cooperate in the 

ANSS. The ANSS is a cooperative effort that emphasizes regional implementation and 

national integration. Progress has been made possible by dedicated community, 

including the ANSS regions, organizations represented in the ANSS Steering Committee, 

and organizations participating in the ANSS, as highlighted below.

ANSS Regions

Alaska

California

Hawaii

Intermountain West

Central and eastern United States

Pacific Northwest

Puerto Rico and U.S. Territories

Organizations Represented in 

ANSS National Steering Committee

Association of American State Geologists

Consortium of Organizations for Strong Motion Observation Systems

Earthquake Engineering Research Institute

Incorporated Research Institutions for Seismology

National Emergency Management Association

Seismological Society of America

U.S. Geological Survey 

Organizations Participating in ANSS in 2016

Alaska Earthquake Center, University of Alaska, Fairbanks

Center for Earthquake Research and Information, University of Memphis

Earthquake Center, Saint Louis University

Lamont-Doherty Cooperative Seismographic Network, Columbia University

Nevada Seismological Laboratory, University of Nevada, Reno

Pacific Northwest Seismic Network, University of Washington and University of Oregon

Puerto Rico Seismic Network, University of Puerto Rico, Mayagüez

Seismograph Stations, University of Utah

Seismological Laboratory, California Institute of Technology

Seismological Laboratory, University of California, Berkeley

South Carolina Seismic Network, University of South Carolina

U.S. Geological Survey (USGS) Earthquake Science Center, Menlo Park, Calif.

USGS Geologic Hazards Science Center, Golden, Colo.

USGS Hawaiian Volcano Observatory, Hawaii National Park, Hawaii
Acknowledgments

This report was written by Cecily Wolfe and John Filson of 

the U.S. Geological Survey (USGS). This document benefitted 

from input from all of the Advanced National Seismic System 

(ANSS) community. Especially recognized for their contributions 

are the members of the ANSS National Steering Committee, 

the ANSS National Implementation Committee, and the 

Scientific Earthquake Studies Advisory Committee to the 

USGS Earthquake Hazards Program; and Greg Beroza of 

Stanford University; Bill Leith, David Applegate, Paul Earle, 

and Lind Gee of the USGS; and Walter Arabasz and Kris Pankow 

of the University of Utah.
Contents

Preface ...........................................................................................................................................................iii

Acknowledgments........................................................................................................................................iv

Executive Summary....................................................................................................................................viii

Introduction.....................................................................................................................................................2

Background.....................................................................................................................................................4

History of the Advanced National Seismic System ........................................................................4

Basic Concepts of Seismic and Real-Time Geodetic Networks...................................................4

Overview of the Current Advanced National Seismic System...............................................................6

Elements of the Advanced National Seismic System.....................................................................6

Organization and Coordination...........................................................................................................9

Advanced National Seismic System Progress to Date (2000–2016) .....................................................9

Network Infrastructure........................................................................................................................9

Standardization and Coordination ...................................................................................................10

Partnerships in Growth......................................................................................................................10

Products and Services.......................................................................................................................12

Advanced National Seismic System Development Opportunities (2017–2027).................................18

Ensuring Readiness in an Earthquake Crisis..................................................................................18

Advancing Earthquake Safety in Urban Areas ..............................................................................22

Developing Earthquake Early Warning Systems ..................................................................22

Developing High-Resolution Damage and Impact Assessments for Urban Areas .......22

Developing High-Resolution Damage and Impact Assessments for 

Critical Facilities and Lifelines ...................................................................................22

Implementing Aftershock Forecasting as a National Capability ......................................24

Expanding the Observational Database for Earthquake Risk Reduction ..................................24

Monitoring Data for Determining the Seismic Response of Structures

 and Lifelines .................................................................................................................24

Developing Comprehensive Assessments of Human-Induced 

Earthquake Hazard and Risk ......................................................................................24

Incorporating Geodetic Data into Rapid, Comprehensive 

Earthquake Impact Assessments..............................................................................26

Improving Coverage in the Central and Eastern United States ........................................26

Expanding Coverage in Areas of High Seismic Hazard......................................................26

Conclusions...................................................................................................................................................27

References Cited..........................................................................................................................................28

 v
Appendix: Planning Considerations for 2017–2027 ................................................................................29

Current Resources and Responsibilities.........................................................................................29

Development Needs and Outcomes for 2017–2027.......................................................................29

Opportunity A. Ensuring Readiness in an Earthquake Crisis..............................................29

Opportunity B. Advancing Earthquake Safety in Urban Areas ..........................................30

Priority B.1. Developing Earthquake Early Warning Systems ...................................30

Priority B.2. Developing High-Resolution Damage and 

Impacts Assessment for Urban Areas.............................................................30

Priority B.3. Developing High-Resolution Damage and 

Impact Assessments for Critical Facilities and Lifelines..............................30

Priority B.4. Implementing Aftershock Forecasting as a National Capability.........31

Opportunity C. Expanding the Observational Database for 

Earthquake Risk Reduction.........................................................................................31

Priority C.1. Monitoring Data for Determining the 

Seismic Response of Structures and Lifelines...............................................31

Priority C.2. Developing Comprehensive Assessments of 

Human-Induced Earthquake Hazard and Risk ...............................................31

Priority C.3. Incorporating Geodetic Data into Rapid, 

Comprehensive Earthquake Impact Assessments........................................31

Priority C.4. Improving Coverage in the Central and Eastern United States...........32

Priority C.5. Expanding Coverage in Areas of High Seismic Hazard ........................32

Resources—Existing and Needed...................................................................................................32

Sidebars

1. United States National Seismic Hazard Model .......................................................................3

2. Contribution of Geodetic Data in the Advanced National Seismic System........................5

3. Distribution of Advanced National Seismic System Seismic Stations ................................7

4. Instrumented Structures in the Advanced National Seismic System .................................8

5. Growth in the Number of Advanced National Seismic System Stations ..........................11

6. ShakeMap....................................................................................................................................13

7. Prompt Assessment of Global Earthquakes for Response (PAGER)..................................19

8. Did-You-Feel-It? ..........................................................................................................................20

9. Earthquake Early Warning.........................................................................................................23

10. Induced Seismicity .....................................................................................................................25

Table

A1. Advanced National Seismic System current annual resources and augmentation 

to resource allocation needed to fully implement each development opportunity 

from 2017 to 2027.........................................................................................................................32

vi 
 vii

Abbreviations

ANSS Advanced National Seismic System

ASL Albuquerque Seismological Laboratory

Caltech California Institute of Technology

CESMD Center for Engineering Strong Motion Data

CEUSN Central and Eastern United States Network

CGS California Geological Survey

CISN California Integrated Seismic Network

ComCat ANSS Comprehensive Catalog

DOT Department of Transportation

DYFI Did-You-Feel-It?

EEW earthquake early warning

ENS Earthquake Notification Service

FEMA Federal Emergency Management Agency

FY fiscal year

GNSS Global Navigation Satellite System

GPS Global Positioning System

IRIS Incorporated Research Institutions for Seismology

M magnitude

MEMS micro-electro-mechanical system

NEHRP National Earthquake Hazards Reduction Program

NEIC National Earthquake Information Center

NOAA National Oceanographic and Atmospheric Administration

NRC U.S. Nuclear Regulatory Commission

NSF National Science Foundation

NSHM National Seismic Hazard Model

PAGER Prompt Assessment of Global Earthquakes for Response

PBO Plate Boundary Observatory

SESAC Scientific Earthquake Studies Advisory Committee

USAID/OFDA U.S. Agency for International Development, Office of Foreign Disaster Assistance

USGS U.S. Geological Survey

VA U.S. Department of Veterans Affairs
By U.S. Geological Survey

Advanced National Seismic System

Current Status, Development Opportunities, and Priorities for

2017–2027

Executive Summary 

Earthquakes pose a threat to the safety of over 143 million 

people living in the United States. Earthquake impacts can be 

significantly reduced if communities understand their risk and 

take proactive steps to mitigate that risk. The Advanced National 

Seismic System (ANSS) is a cooperative effort to collect and 

analyze seismic and geodetic data on earthquakes, issue timely 

and reliable notifications of their occurrence and impacts, and 

provide data for earthquake research and the hazard and risk 

assessments that are the foundation for creating an earthquakeresilient nation.

As a result of investments made in the ANSS, any earthquake 

of significance in the United States or anywhere in the world 

can now be rapidly characterized by a suite of products, providing 

situational awareness during times of crisis. ANSS monitoring 

serves scientific research and earthquake engineering needs, 

including advancing the understanding of how buildings and 

other structures perform in an earthquake.

As one of four Federal agencies participating in the 

National Earthquake Hazards Reduction Program (NEHRP), 

the U.S. Geological Survey provides management and financial 

support for the ANSS. Congress established the ANSS as a 

NEHRP facility in the 2000 reauthorization of the NEHRP 

(Public Law 106–503).

The ANSS is a collaboration of Federal, State, and academic 

partners. Recognizing that earthquake hazard and risk varies 

from region to region, the ANSS management structure 

emphasizes regional implementation and national integration. 

Its organization allows collaboration with other Federal and 

State agencies and with the earth science and engineering 

communities with interests in seismic monitoring.

The ANSS promotes partnerships among those working 

at local, regional, and national levels committed to reducing 

earthquake losses. These partnerships are necessary in order 

for the ANSS to be coordinated nationally, designed and 

implemented regionally, and supported locally. Moreover, 

host academic institutions, some State agencies, other Federal 

agencies, private foundations, and scientific organizations 

have contributed support to ANSS growth and (or) operations.

The ANSS requirements were originally described in 

a U.S. Geological Survey (1999) publication entitled 

“An Assessment of Seismic Monitoring in the United States—

Requirement for an Advanced National Seismic System”; 

these needs included strengthening coordination among the 

nation’s monitoring networks, developing new earthquake 

information products, and expanding monitoring infrastructure 

nationwide. Since 2000, the ANSS has strengthened infrastructure 

and partnerships, and developed new earthquake information 

products and services. Although the funding to fully implement 

the ANSS vision has not been realized, at the end of fiscal year 

2016 the ANSS achieved 42 percent of the goal set in 1999 

for the installation of 7,100 modern seismic stations in the 

free field and in buildings, bridges, and other structures. The 

timeliness and usefulness of ANSS products have increased 

the expectations of its capabilities within government agencies, 

emergency responders, the public, and the engineering and 

scientific communities. 
Executive Summary 1

The reporting of earthquakes has been revolutionized as 

a result of ANSS investments. Notable ANSS products and 

services include immediate earthquake notifications to 

governments and emergency managers, rapid notification by email 

or text via the Earthquake Notification Service, earthquake 

source characteristics, ANSS websites with real-time earthquake 

information, a suite of real-time situational awareness products 

(ShakeMap, ShakeCast, Prompt Assessment of Global 

Earthquakes for Response [PAGER], Did-You-Feel-It?), a 

catalog of information (the ANSS Comprehensive Catalog), 

and products for engineers served by the Center for Engineering 

Strong Motion Data.

To meet the expectations of the next decade, the ANSS must 

focus on improving the robustness of essential services and 

retaining capacity for future innovation. The ANSS has the 

capacity to further improve earthquake safety and support 

response and recovery nationwide. This document describes a set 

of specific development opportunities that form ANSS priorities 

for the next decade to ensure ANSS readiness in an earthquake 

crisis, advance earthquake safety in urban areas, and expand the 

observational database for earthquake risk reduction. Additional 

funding would be necessary to realize these opportunities.

When the ANSS was formed, it was viewed as an innovative 

but risky endeavor, yet now it has proved successful despite 

being only partially funded. Resting on past accomplishments 

and accepting the status quo will increase exposure to earthquake 

risks as our nation grows and its structural systems expand

and become more complex. To fully realize its loss reduction 

potential, the ANSS must move forward—the tectonic forces 

that cause earthquakes are relentless, they will not stop and

neither can efforts to reduce their impacts throughout the Nation.
2 Advanced National Seismic System—Current Status, Development Opportunities, and Priorities for 2017–2027

Introduction

Earthquakes are a national hazard (sidebar 1, p. 3), with 

more than 143 million people exposed to potentially damaging

shaking in the United States (Jaiswal, Petersen, and others, 

2015). There are tens of thousands of earthquakes above 

magnitude (M) 2.5 strong enough to be felt in the United 

States each year. Large earthquakes (≥M5) pose threats to the 

safety of individuals and to the national economy, infrastructure, 

and security.

Estimated long-term “annualized earthquake losses” from 

earthquakes in the United States are over $4.5 billion per year 

(Jaiswal, Bausch, and others, 2015). This estimate is only for 

building-related losses, and does not include components such 

as utility and transportation losses, business interruption, and 

the losses associated with deaths and injuries. The M7.8 1906 

San Francisco earthquake is known as the most devastating 

U.S. earthquake on record, but the Nation’s history contains 

many earthquakes whose repeat occurrence today would be 

catastrophic, including those in southeastern Missouri in 1811 

and 1812 (three events greater than M7); southern California 

in 1857 (M7.9); Hawaii Island in 1868 (M7.9); Charleston, S.C., 

in 1886 (M7.3); the Pacific Northwest in 1700 (M9); and Alaska 

in 1964 (M9.2). Recent damaging earthquakes in the United States 

illustrate potential economic losses: $6 to $10 billion in 

Loma Prieta (M6.9, San Francisco, Calif., 1989), $20 billion 

in Northridge (M6.7, Los Angeles, Calif., 1994), and $2 billion 

in Nisqually (M6.8, Seattle, Wash., 2001). International examples 

include $100 billion in losses in Kobe, Japan (M6.9, 1995), 

$30 billion in Maule, Chile (M8.8, 2010), $30 billion in 

Christchurch, New Zealand (M6.1, 2011), and $300 billion in 

Tohoku, Japan (M9.0, 2011). 

The Advanced National Seismic System (ANSS) is a 

cooperative effort to collect and analyze seismic and geodetic 

data on earthquakes, issue timely and reliable notifications of 

their occurrence and impacts, and provide data for earthquake 

research and the hazard and risk assessments that are the 

foundation for creating an earthquake-resilient nation. Life-saving 

and loss-reduction measures require accurate, timely earthquake 

information, and the benefits of fully deploying the ANSS far 

exceed the costs of building and operating it (National Research 

Council, 2006). Members of professions working to mitigate 

earthquake risks depend on monitoring: for example, earth 

scientists focused on the cause and nature of strong shaking and 

the quantification of the hazard, and earthquake engineers 

working to design safe structures. Other users include emergency 

managers, insurance professionals, economists, and policy 

analysts. Earthquake monitoring information is critical for 

effective building codes that support nearly $1 trillion in new 

construction each year in the United States. 

The vision of the ANSS is to provide the earthquake data 

and information needed to save lives and reduce earthquake 

economic losses, as a foundation for creating a more earthquakeresilient nation. 

The mission of the ANSS is to provide accurate and timely 

data and information on seismic events and their effects on 

buildings and infrastructure, to cooperatively develop and 

maintain the system with consistent analytical procedures, and 

to develop information products and services necessary for 

earthquake warnings, notifications, impact estimates, hazard 

and risk assessments, and scientific and engineering research. 

There are four areas in which ANSS earthquake monitoring 

has practical application to public safety through earthquake 

loss reduction:

Public awareness.—The ANSS rapidly provides information 

on earthquake occurrence, characterizing any seismic event 

causing public concern for situational awareness. There is great

demand for such information in times of crisis: following a 

large earthquake, ANSS websites can receive millions of visits. 

Through the earthquake early warning (EEW) initiative, the 

ANSS is developing the capability to issue alerts of imminent 

strong ground shaking. 

Emergency response.—ANSS information on the severity 

and spatial distribution of earthquake shaking and the likely 

societal impacts is essential to give rapid estimation of the scope 

of damages and losses for emergency response. The ANSS 

also enables earthquake scenarios that are used in emergency 

management exercises.

Earthquake hazard assessment and risk mitigation.—

ANSS information and complementary geologic data form the 

basis of hazard assessments used in building codes and other 

risk-reduction measures (such as the National Seismic Hazard 

Model, which is a suite of products aimed at improving 

earthquake-resilient construction in the United States).

Earthquake and engineering research.—The ANSS provides 

data and derived products needed to develop our understanding 

of the causes of earthquakes, their likelihood, and their impacts, 

including impacts on the built environment. ANSS recordings 

of strong ground shaking and associated building response 

are used in the development of seismic-resistant engineering 

design and construction practices.
Introduction 3

1. United States National Seismic Hazard Model

Earthquake hazards nationwide are quantified in the National Seismic Hazard Model (NSHM) (such as 

map below), which is a suite of products aimed at improving earthquake-resilient construction in the 

United States. Engineers who construct buildings need to know how strongly a particular site might be 

shaken by earthquakes. The NSHM addresses this question by compiling all known earthquake sources 

(and proxies for unknown sources), their distance from the site in question, and other seismological and 

geological information to project potential maximum expected ground motions at a site over a particular 

period of time (for example, 50 years) (see Petersen and others, 2014). The NSHM is revised periodically 

to include new research results on earthquake faults, ground deformation, and earthquake ground shaking. 

The NSHM relies on Advanced National Seismic System information. 

Highest hazard

Peak acceleration, 

expressed as a percentage 

of standard gravity (g)

EXPLANATION

Lowest hazard

>64

48–64

32–48

16–32

8–16

4–8

<4

ALASKA

HAWAII

Map of seismic hazard across the United States derived from the National Seismic Hazard Model. Colors on this particular map show 

the levels of horizontal shaking that have a 2% chance of being exceeded in a 50-year period. Shaking is expressed as a percentage of g, 

which is the acceleration of a falling object due to gravity, with red colors indicating highest shaking and thus highest hazard. 
4 Advanced National Seismic System—Current Status, Development Opportunities, and Priorities for 2017–2027

Background

History of the Advanced National Seismic System 

The ANSS is an essential component of the U.S. Geological 

Survey (USGS) contributions to the four-agency National 

Earthquake Hazards Reduction Program (NEHRP), consisting 

of the National Institute of Standards and Technology, National 

Science Foundation (NSF), Federal Emergency Management 

Agency (FEMA), and USGS. Congress established the ANSS 

through the Earthquake Hazards Reduction Act of 2000 

(Public Law 106–503), directing the USGS “...to establish 

and operate an Advanced National Seismic Research and 

Monitoring System to modernize, standardize, and stabilize 

the national, regional, and urban seismic monitoring systems 

in the United States into a coordinated system.” The original 

ANSS design was set down in USGS Circular 1188 entitled 

“An Assessment of Seismic Monitoring in the United States—

Requirement for an Advanced National Seismic System” 

(U.S. Geological Survey, 1999). Technical guidelines for ANSS 

implementation were detailed in a subsequent document, USGS 

Open-File Report 2002–92 (ANSS Technical Implementation 

Committee, 2002). 

This current document describing ANSS developmental 

opportunities and priorities for the next decade (2017–2027) has 

been written at the recommendation of the ANSS Steering 

Committee and its parent body, the Scientific Earthquake 

Studies Advisory Committee (SESAC), which was established 

by Congress to advise the Director of the USGS on matters 

related to the USGS participation in the NEHRP.

Basic Concepts of Seismic and Real-Time 

Geodetic Networks

A seismic station consists of a sensor to measure ground 

motion—a seismometer—and an instrument to convert the 

analog electrical signal to digital format. Because of the broad 

range of motions generated by earthquakes, two types of 

sensors are typically employed. Broadband seismometers can 

record ground motions (velocity or acceleration) that vary over 

many orders of magnitude (1 to 1,000,000) and over a wide 

range of frequencies, whereas strong-motion seismometers are 

needed to record the shaking near large earthquakes, both on 

the ground and in buildings and lifelines. Many ANSS stations 

consist of both broadband and strong-motion sensors to ensure 

that the full range motions are recorded with fidelity.

A seismic network consists of a group of stations feeding 

data to a data analysis center. They are typically described in 

terms of their scale of coverage. National and global networks 

provide wide areal coverage, and regional networks consist of 

more densely spaced seismometers in areas of higher seismic 

hazard to detect lower magnitude earthquakes and increase the 

accuracy of earthquake characterization. Data analysis centers 

aggregate data from many seismic stations to produce accurate 

earthquake products.

A seismic station with broadband and strong-motion sensors 

recorded at 100 samples per second would produce approximately 

14 kilobits per second of data. These data are transmitted 

continuously, using various types of communication pathways, 

to a data center for analysis. A data center using a network of 

100 stations would acquire and process over 400 gigabytes of 

data per month. These data must also be archived and freely 

and openly distributed for long-term research.

Seismic network operations require an expert staff of 

scientists, engineers, and technicians who analyze earthquakes; 

manage software, computers, data flow, and communications; 

and conduct fieldwork to maintain seismic stations. 

The opportunities described herein include a new role 

for geodetic networks, identifying a pathway to eventually 

become participating networks in the ANSS. A real-time 

geodetic network uses high-precision Global Positioning 

System (GPS) stations (more generally called Global 

Navigation Satellite System [GNSS] stations) to rapidly 

measure ground displacement. Geodetic and seismic data are 

complementary, and joint analysis can better characterize an 

earthquake. Real-time GNSS data are particularly important 

for rapidly characterizing large earthquakes for earthquake 

early warning and in resolving detailed characteristics of fault 

slip (sidebar 2, p. 5).
Background 5

2. Contribution of Geodetic Data in the Advanced

National Seismic System

The potential contribution of real-time geodetic data from Global Navigation Satellite System (GNSS) 

networks to rapid earthquake characterization was demonstrated retrospectively for the Tohoku-Oki 

earthquake (left plot). For the largest earthquakes, GNSS data can provide a more accurate rapid magnitude 

estimate than seismic data and simultaneously help to estimate the earthquake source dimensions. The west 

coast of the United States already has hundreds of continuously operating GNSS that could be incorporated 

into the ANSS; many of these are operated by USGS cooperator institutions and partners (for example, 

the Plate Boundary Observatory (PBO) geodetic network, operated by UNAVCO). The Tohoku example 

emphasizes the role that geodetic data could play in a future great earthquake on the Cascadia subduction 

zone, the Alaska-Aleutian subduction zone, or the Puerto Rico subduction zone. Geodetic instruments can 

also record instantaneous large offsets on faults like the San Andreas, contributing to improved earthquake 

early warning and providing real-time assessment of damage to fault-crossing lifelines. 

138° 139° 140° 141° 142° 143° 144° 145°

35°

36°

37°

38°

39°

40°

41°

42°

80

60

40

Slip (m)

20

Contour interval—

10 m

EXPLANATION

Fault

Thrust fault—

Sawteeth on

upper plate

Strike-slip

fault

1 meter

0 50 KILOMETERS

Map showing real-time geodetic data of the magnitude 9 

Tohoku-Oki earthquake collected by Global Navigation 

Satellite System (GNSS) stations (GNSS displacements 

are shown as black arrows and fault slip is shown as 

colored contours). Figure courtesy of Jessica Murray 

and Sarah Minson.

-125° -120° -115° -110°

35°

40°

45°

Map showing the locations of GNSS stations (blue 

circles) along the west coast of the United States that 

could be used in the same manner (plate boundary 

shown by red lines, with barbed line indicating 

subduction zone). Figure courtesy of Jessica Murray 

and Sarah Minson.
6 Advanced National Seismic System—Current Status, Development Opportunities, and Priorities for 2017–2027

Overview of the Current 

Advanced National Seismic System

The ANSS consists of national and regional seismic 

networks (sidebar 3, p. 7) and associated data centers. The 

USGS Earthquake Hazards Program supports national facilities 

and partially supports regional seismic networks; the latter 

can receive additional support from their States, their host 

universities, or other Federal agencies. The USGS Earthquake 

Hazards Program provided $30.8 million in 2016 to support 

the ANSS.

The original ANSS design called for the installation of 

7,100 modern seismic stations, both in the field and in buildings, 

bridges, and other structures. The ANSS is currently 42-percent 

complete in terms of the number of seismic stations installed, 

and further growth is required to complete the ANSS. 

Elements of the Advanced National 

Seismic System 

Regional seismic networks.—Regional seismic networks 

provide critical station coverage in moderate- to high-hazard 

regions, perform important functions of analyzing and distributing 

seismic data and information on earthquakes, and provide 

local expertise for a region’s engineering and emergency 

management communities and for the public. Most networks 

monitor a unique geographic region where their earthquake 

locations and magnitudes are considered the authoritative 

ANSS result. The 11 networks participating in the ANSS in 

2016 are listed below.

• Alaska Earthquake Center of the Geophysical Institute, 

University of Alaska Fairbanks

• California Integrated Seismic Network (CISN), the 

principal units of which are networks and data centers 

operated by the California Institute of Technology 

(Caltech), the University of California (UC) Berkeley, 

and the USGS Earthquake Science Center at Menlo 

Park, which are all participants in ANSS, as well as the 

California Geological Survey

• Center for Earthquake Research and Information, 

University of Memphis

• Lamont-Doherty Cooperative Seismographic Network, 

Columbia University

• Nevada Seismological Laboratory, University of 

Nevada, Reno

• Pacific Northwest Seismic Network, operated by the 

University of Washington and University of Oregon

• Puerto Rico Seismic Network, University of Puerto 

Rico, Mayaguez

• Saint Louis University Earthquake Center

• South Carolina Seismic Network, University of 

South Carolina

• University of Utah Seismograph Stations

• USGS Hawaiian Volcano Observatory 

National elements.—The USGS operates the three national 

elements of the ANSS: the National Earthquake Information 

Center (NEIC), the National Seismic Network, and the 

National Strong Motion Project.

The NEIC receives data from some 3,000 national and 

worldwide seismic stations. It is staffed 24/7 and serves as 

a backup for regional networks. The NEIC reports on about 

25,000 earthquakes per year. 

The National Seismic Network, or “ANSS backbone” 

network, consists of 100 broadband stations providing a national 

framework for the ANSS earthquake monitoring. These stations 

are operated by the USGS Albuquerque Seismological Laboratory 

(ASL), which also operates two regional networks: the New 

England Seismic Network and the Intermountain West Seismic 

Network in Wyoming.

The National Strong Motion Project maintains stations 

designed to record strong shaking near earthquakes, with more 

than 400 free-field stations and more than 150 instrumented 

structures (sidebar 4, p. 8) with telemetry. Guidelines for

deployments to collect the structural response data were published 

in USGS Open-File Report 2005–1039 entitled “Guideline for 

ANSS Seismic Monitoring of Engineered Civil Systems” 

(ANSS Structural Instrumentation Guideline Committee, 2005).

Portable capabilities.—The ANSS also maintains sets of 

portable equipment for temporary seismometer deployments, 

including aftershock monitoring. ANSS portable capabilities have 

proven important for many earthquake sequences, including 

the study of induced earthquake sequences in several States 

and earthquake aftershock investigations, such as after the 

2014 M6.0 South Napa, Calif.; the 2011 M5.8 Mineral, Va.; 

and the 2002 M7.9 Denali, Alaska, earthquakes and the 2007 

collapse of the Crandall Canyon mine in Utah.
Overview of the Current Advanced National Seismic System 7

3. Distribution of Advanced National Seismic System 

Seismic Stations

The Advanced National Seismic System (ANSS) is composed of national and regional seismic networks, 

which are made up of modern digital seismic stations that have broadband or strong motion sensors, 

or both, to permit recording of the broad range of motions created by earthquakes. As the ANSS has 

grown, stations have been deployed strategically, such as to improve coverage in high hazard regions 

and in high risk urban areas. The opportunities described later in this report describe how further 

increases in ANSS station coverage can provide benefits.

ALASKA

PUERTO RICO

HAWAII

#*

#*

#*

EXPLANATION

Stations

Broadband

Broadband/strong motion

Strong motion

Peak acceleration, 

expressed as a percentage 

of standard gravity (g)

 Highest hazard

>40

 20–40

 16–20

 10–16

 7–10

 5–7

 3–5

 2–3

 1–2

 <1

 Lowest hazard

#*

#*

#*

EXPLANATION

Stations

Broadband

Broadband/strong motion

Strong motion

Peak acceleration, 

expressed as a percentage 

of standard gravity (g)

 Highest hazard

>40

 20–40

 16–20

 10–16

 7–10

 5–7

 3–5

 2–3

 1–2

 <1

 Lowest hazard

#*

#*

#*

EXPLANATION

Stations

Broadband

Broadband/strong motion

Strong motion

Peak acceleration, 

expressed as a percentage 

of standard gravity (g)

 Highest hazard

>40

 20–40

 16–20

 10–16

 7–10

 5–7

 3–5

 2–3

 1–2

 <1

 Lowest hazard

Map of Advanced National Seismic System free field seismic stations across the United States in 

2016, which are operated by national and regional seismic networks. Background shading illustrates 

higher hazard regions in the National Seismic Hazard Model (see sidebar 1, p. 3). Notice the greater 

density of seismic stations in regions with either higher hazard, higher risk, or both. Figure courtesy 

of Harley Benz and Gregory Smoczyk.
8 Advanced National Seismic System—Current Status, Development Opportunities, and Priorities for 2017–2027

4. Instrumented Structures in the Advanced National

Seismic System

The Advanced National Seismic System (ANSS) includes instrumented structures as well as free-field 

stations (sidebar 2, p. 5). Sensors in buildings are needed to help engineers and scientists to understand 

behavior and performance of the built environment in an earthquake (for example, the instrumented Rincon 

Tower I building in San Francisco, Calif., as seen in the diagram to the right). Representative structures are 

instrumented to address unresolved issues in seismic design, retrofitting practices, and building codes as 

well as provide validation of experimental and simulation research. When a major earthquake occurs, it is 

important to measure how design and retrofit concepts respond to actual earthquake shaking so that they 

can be more generally adopted or adapted as warranted. 

Diagram of one of the 168 instrumented structures in the Advanced National Seismic System (ANSS), showing the placement of sensors 

and other instrumentation as well as the displacements that were measured during an earthquake. The Rincon Tower I building is a 

jointly instrumented (by the California Geologic Survey [CGS] and U.S. Geological Survey [USGS]) 64-story reinforced concrete building 

in San Francisco, Calif. It has core shear walls and an outrigger perimeter column system connected to the core with buckling restrained 

braces and tuned sloshing liquid dampers. The seismic instrumentation of the building has 72 channels and real-time streaming capability. 

The schematics on the left are north-south and east-west cross sections of the building showing the locations and orientation of the 

accelerometers used by the ANSS to monitor the structural response. The central figure shows a 3-dimensional model of the building. The 

right figure shows examples of north-south displacements at different levels of the building recorded during the magnitude 6.0 earthquake 

located in South Napa, Calif., on August 24, 2014. Figure courtesy of Mehmet Çelebi and Vivian Nguyen.

CSMIP (CGS) sensors

EXPLANATION

NSMP (USGS) sensors

Core shear walls

Uniaxial

Uniaxial

Uniaxial Tuned sloshing liquid damper

BRB Buckling restrained brace

TSD

CSMIP (CGS) Station No. 58389

NSMP (USGS) Station No. 8389

M6.0 August 24, 2014 Napa earthquake

steel

BRB

Elevation B–B' (E/W)

North-South displacements

TSD

Elevation A–A' (N/S)

OutriggerOutrigger

OutriggerOutrigger

188.31 meters

LEVEL 24

LEVEL 28

LEVEL 32

LEVEL 64 (ROOF)

LEVEL 61

LEVEL 55

LEVEL 51

LEVEL 18

LEVEL 7

LEVEL 1

2 centimeters

20 SECONDS
Overview of the Current Advanced National Seismic System 9

Organization and Coordination

The ANSS is organized with the following elements 

to ensure oversight from stakeholders, task managers with 

responsibilities, and facilitate communication and coordination: 

• National Steering Committee.—The ANSS National 

Steering Committee (composed of representatives from 

various professional groups) provides comprehensive 

guidance and oversight for the entire ANSS effort. It 

reports through the SESAC. 

• Regional Advisory Committees.—ANSS Regional 

Advisory Committees (composed of end users of 

seismic information, such as practicing engineers, 

emergency managers, seismologists, utility operators, 

transportation officials, and so forth) provide guidance 

and oversight for the ANSS at their respective 

geographic levels. 

• National Implementation Committee.—Implementation 

and operations are carried out under the oversight of the 

ANSS National Implementation Committee composed 

of regional and topical representatives.

• ANSS Coordinator and ANSS Technical Manager.—

The ANSS Coordinator on the staff of the USGS 

Earthquake Hazards Program oversees the activities of 

the ANSS, including the seismic network cooperative 

agreements, and is also the chief spokesperson for 

the ANSS at the national level. The ANSS Technical 

Manager provides scientific and technical expertise for 

the effort.

Overall responsibility for implementation and operation 

of the ANSS lies with the USGS, but this organization allows 

collaboration with other Federal and State agencies and with

the earth science and engineering communities with interests in 

seismic monitoring. Fundamental to the success of the ANSS 

is the need to promote partnerships among those working at 

local, regional, and national levels committed to reducing 

earthquake losses. These partnerships are necessary in order 

for the ANSS to be coordinated nationally, designed and 

implemented regionally, and supported locally. Recognizing 

that earthquake hazard and risk varies from region to region, 

the ANSS management structure emphasizes regional 

implementation and national integration.

Advanced National Seismic System 

Progress to Date (2000–2016)

ANSS progress from 2000 to 2016 can be categorized in

four broad areas—network infrastructure, standardization and 

coordination, partnerships in growth, and products and services.

Network Infrastructure

When the ANSS began in 2000, most seismometers used 

in the United States could record earthquakes only over narrow 

amplitude and frequency ranges and thus were not capable 

of recording the signals generated by large earthquakes. Data 

were transmitted over noisy, unreliable analog circuits, and 

some data were still entered and analyzed by hand.

The ANSS has since modernized and expanded the 

participating seismic networks and data analysis centers. By end 

of FY 2016, the ANSS was 42-percent complete in terms of the 

number of seismic stations (sidebar 5, p. 11). An acceleration 

of growth in 2010–12 was mostly due to a one-time increase in 

funding ($19 million) to modernize networks, received under 

the American Recovery and Reinvestment Act. The ANSS is 

now capable of detecting almost all humanly felt earthquakes 

in the United States, except in parts of Alaska. The ANSS has 

also expanded its portable deployment capabilities. 

The ANSS has spurred innovation: for example, the 

ANSS worked with private-sector manufacturers to develop a 

relatively inexpensive “NetQuakes” strong motion sensor and, 

from 2009 through 2014, over 400 NetQuakes sensors were 

deployed in select urban areas (for example, Anchorage, Alaska; 

Boston, Mass.; Las Vegas, Nev.; Los Angeles, Calif.; 

Memphis, Tenn.; New York, N.Y.; Portland, Oreg.; Salt Lake City, 

Utah; Reno, Nev.; San Francisco, Calif.; Seattle, Wash.; and 

Washington, D.C.), hosted by private citizens in their homes. 

Advances in low-cost, micro-electro-mechanical system 

(MEMS) sensor technology hold future promise for the ANSS.

Strong-motion recordings of damaging seismic waves in the 

proximity of an earthquake provide information that is essential 

for advances in ground-motion prediction estimation, improved 

modeling of ground deformation and soil-structure interaction, 

validation of structural simulation and loss assessment tools, 

and improvements in seismic design standards for buildings, 

bridges, and other critical infrastructure.
10 Advanced National Seismic System—Current Status, Development Opportunities, and Priorities for 2017–2027

Standardization and Coordination

The ANSS has advanced the coordination and standardization 

of operations, implementing common instrument standards, data 

formats, software, and operational procedures. Each seismic 

network is assigned a geographic region where its solutions are 

considered “authoritative.” ANSS components act as a 

well-coordinated, collaborative system. The ANSS promotes 

communication and coordination between various Federal, State 

and private agencies, as well as scientists and engineers involved 

with earthquake monitoring both regionally and nationally.

Partnerships in Growth 

Partnerships have increased the effectiveness of the ANSS. 

Host academic institutions; the States of Alaska, Arkansas, 

California, Nevada, Oregon, Tennessee, Utah, and Washington 

among others; and other Federal agencies, such as the U.S. 

Departments of Energy and Veterans Affairs, have contributed 

to ANSS growth and operations. The California Governor’s 

Office of Emergency Services supports the CISN, which also 

received supplemental funding from FEMA requested through 

the cities of Los Angeles and Long Beach for network expansion. 

The Gordon and Betty Moore Foundation contributed significantly 

to the development of earthquake early warning, and the Keck 

Foundation and the Murdock Foundation have contributed to 

regional network improvements under the ANSS. 

Growth of the ANSS National Seismic Network (“ANSS 

backbone”) and certain regional networks was enhanced through 

the USArray element of EarthScope, a National Science 

Foundation (NSF) facility implemented through the Incorporated 

Research Institutions for Seismology (IRIS). Prompt Assessment 

of Global Earthquakes for Response (PAGER) development 

was supported by the U.S. Agency for International Development, 

Office of Foreign Disaster Assistance (USAID/OFDA). 

ShakeCast development was supported by the International 

Atomic Energy Agency, the U.S. Nuclear Regulatory 

Commission (NRC), and the U.S. Department of Veterans 

Affairs (VA). The California Department of Transportation has 

also been an important supporter of ShakeCast development, 

and the Departments of Transportation (DOTs) in the States of 

Idaho, Mississippi, Oklahoma, Oregon, South Carolina, Texas, 

Utah, and Washington have recently made plans to commit 

support to further customize ShakeCast to meet the needs of 

State DOTs.

Strong-motion data are archived and distributed by the 

Center for Engineering Strong Motion Data (CESMD), a 

partnership between the ANSS and the California Geological 

Survey. The Northern California and Southern California 

earthquake data centers are operated by UC Berkeley and 

Caltech, respectively. With NSF funding, the IRIS Data 

Management Center archives and provides distribution for a 

portion of ANSS seismic data. 

The Global Seismographic Network, operated as a 

partnership among the USGS, NSF, and IRIS, is of critical 

importance for the following hazard monitoring efforts:

• the NEIC’s global monitoring of earthquakes, 

• the National Oceanographic and Atmospheric 

Administration’s (NOAA’s) tsunami monitoring, and 

• the U.S. Air Force and U.S. Department of Energy 

research programs for nuclear-test monitoring.

The ANSS National Steering Committee includes 

representatives from the Association of American State 

Geologists, the Consortium of Organizations for Strong Motion 

Observation Systems, the Earthquake Engineering Research 

Institute, IRIS, the National Emergency Management Association, 

and the Seismological Society of America. Members of the 

scientific, engineering, and emergency response communities 

participate in ANSS Regional Advisory Committees. The 

Southern California Earthquake Center and the Pacific 

Earthquake Engineering Research Center have also provided 

noteworthy forums for the users of ANSS data.
Advanced National Seismic System Progress to Date (2000–2016) 11

5. Growth in the Number of Advanced National

Seismic System Stations

Since its inception, the U.S. Geological Survey (USGS) and its university partners have deployed over 

2,900 Advanced National Seismic System (ANSS) stations. ANSS station growth accelerated in 2010–12 

through an influx of funding to the USGS under the American Recovery and Reinvestment Act. Growth rates 

since then have remained high owing to investments in a west coast earthquake early warning system. 

However, a small decline occurred in fiscal year 2015 when, because of funding limitations, the USGS 

ended support for two regional seismic networks and because of the closure of some additional stations. Number of stations

Fiscal year

0

500

1000

1500

2000

2500

3000

2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016

Graph showing the total number of Advanced National Seismic System (ANSS) stations in each fiscal year (FY) from FY 2000 

through FY 2016. Figure courtesy of Cecily Wolfe.
12 Advanced National Seismic System—Current Status, Development Opportunities, and Priorities for 2017–2027

Products and Services

The reporting of earthquakes has been revolutionized as 

a result of ANSS investments. Example ANSS products and 

services include the following:

• Immediate earthquake notifications to governments 

and emergency managers. The ANSS reports on 

potentially damaging earthquakes to the White House; 

the Departments of Defense, Homeland Security 

(including FEMA), Transportation, Energy, Commerce 

(NOAA, National Institute of Standards and Technology), 

Veterans Affairs, State, and Interior; State offices for 

disaster services; and the news media. Additionally, 

regional seismic networks serve as resources for State 

and local community information needs. 

• Earthquake Notification Service (ENS). The ENS 

is a free public service sending rapid earthquake 

notifications via e-mail and text message to 

approximately 400,000 users. Notification criteria 

can be tailored to meet users’ needs via an easy-to-use 

web interface.

• Web presence. The USGS and regional seismic 

networks each maintain websites that provide 

authoritative and coordinated information on recent 

earthquakes, including maps and lists of recent 

seismicity. Following a large earthquake, these sites can 

receive millions of visits within hours. For example, 

the earthquakes.usgs.gov website is one of the most 

heavily trafficked sites in the Federal Government. 

Technical information on ANSS operations can also 

be found on these websites.

• ShakeMap. Based on ANSS data, a ShakeMap, a map 

of the severity and spatial distribution of earthquake 

ground shaking following an earthquake, is generated. 

It provides a rapid assessment of the scale of an 

earthquake’s potential impact (sidebar 6, p. 13–17). 

This informs response officials and personnel at all 

levels of government, transportation and lifeline managers, and the public of what damage levels to expect 

and the scope of the needed response. 

• ShakeCast. ShakeCast is an application for automating 

ShakeMap delivery to critical users and for facilitating 

notification of shaking levels at user-selected facilities. 

It is used by numerous public and private infrastructure 

management centers (such as, State DOTs, utilities, 

school systems, Federal agencies, private companies, 

and critical facilities) to prioritize earthquake response 

actions. Users identify site locations beforehand and 

set thresholds for shaking levels of concern. Immediately 

after an earthquake, a ShakeMap is distributed to 

clients with estimated shaking levels at their sites and 

information about potential problems. ShakeCast is 

particularly useful for transportation or lifeline 

networks, where there may be hundreds of bridges and 

overpasses to oversee, and helps clients prioritize 

safety inspections. After the 2011 Mineral, Va., 

earthquake, ShakeCast alerted the Nuclear Regulatory 

Commission that the design shaking levels at the North 

Anna nuclear power plant may have been exceeded. 

• Prompt Assessment of Global Earthquakes for 

Response (PAGER). The PAGER system (sidebar 7, 

p. 19) estimates dollar losses and fatalities immediately 

after significant earthquakes nationally and worldwide, 

using ShakeMap results along with inventories of 

buildings and construction types and historical loss data. 

PAGER has proved invaluable in informing emergency 

responders, government and aid agencies, and the 

media of the scope of potential disasters associated 

with both domestic and foreign earthquakes.
Advanced National Seismic System Progress to Date (2000–2016) 13

6. ShakeMap 

A ShakeMap is made with Advanced National Seismic System data and provides a near-real-time map 

of ground motion and shaking intensity following a significant earthquake. ShakeMaps are used by 

Federal, State, and local organizations for post-earthquake response and recovery, public and scientific 

information, as well as for preparedness exercises and disaster planning. 

ALASKA

B

A

C

D

A Denali, Alaska

B Nisqually, Washington

C Pawnee, Oklahoma

D American Canyon, California

ShakeMap examples from several earthquakes: A, the 2002 M7.9 Denali, Alaska, earthquake (black lines indicate fault locations

used in the earthquake rupture model; the earthquake rupture began with reverse faulting, indicated by the black box, then evolved 

to strike-slip faulting); B, the 2003 M6.8 Nisqually (Seattle), Wash., earthquake (open circles indicate Did-You-Feel-It? reports); 

C, the 2015 M5.8 Pawnee, Okla., earthquake (open circles indicate geocoded Did-You-Feel-It? reports); and D, the 2014 M6.0 

American Canyon (South Napa), Calif., earthquake (dark gray line indicates the fault location used in the earthquake rupture model, 

whereas red lines indicate other faults in the region). Red star denotes earthquake epicenter and triangles indicate locations of 

seismic stations. Notice how yellow-to-red colors indicate regions of strong, very strong, to severe shaking from each earthquake. 

Maps courtesy of the National Earthquake Information Center and the California Integrated Seismic Network.
14 Advanced National Seismic System—Current Status, Development Opportunities, and Priorities for 2017–2027

A

0 100 200 300 KILOMETERS

INSTRUMENTAL 

INTENSITY

PEAK VEL.(cm/s)

PEAK ACC.(%g)

POTENTIAL 

DAMAGE

PERCEIVED 

SHAKING Not felt Weak Light Moderate Strong Very strong Severe Violent Extreme

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

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

<0.1 0.1-1.1 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

1.1-3.4 3.4-8.1

Anchorage

College

USGS SHAKEMAP : DENALI, ALASKA

Sun Nov 3, 2002 22:12:43 GMT M 7.9 N63.54 W147.73 Depth: 19.0km ID:200211032212

-150° -145° -140°

60°

65°

Map Version 1.1 Processed Sat Nov 8, 2008 11:09:13 PM MST 

N
Advanced National Seismic System Progress to Date (2000–2016) 15

B

INSTRUMENTAL 

INTENSITY

PEAK VEL.(cm/s)

PEAK ACC.(%g)

POTENTIAL 

DAMAGE

PERCEIVED 

SHAKING Not felt Weak Light Moderate Strong Very strong Severe Violent Extreme

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

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

<0.1 0.1-1.1 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

1.1-3.4 3.4-8.1

-124° -122° -120°

46°

48°

Victoria

North Cowichan

Aloha

Saint Helens

Aberdeen

Alderwood Manor

Arlington

Auburn

Bremerton

Centralia

Ellensburg

Kelso Sunnyside

Yakima

USGS SHAKEMAP : NISQUALLY, WASHINGTON

WED FEB 28, 2001 18:54:32 GMT M 6.8 N47.11 W122.60 DEPTH: 54.0KM ID:200102281854

Map Version 1.1 Processed Sat Nov 8, 2008 09:50:37 PM MST 0 50 100 KILOMETERS

N
16 Advanced National Seismic System—Current Status, Development Opportunities, and Priorities for 2017–2027

C

INSTRUMENTAL 

INTENSITY

PEAK VEL.(cm/s)

PEAK ACC.(%g)

POTENTIAL 

DAMAGE

PERCEIVED 

SHAKING Not felt Weak Light Moderate Strong Very strong Severe Violent Extreme

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

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

<0.1 0.1-1.1 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

1.1-3.4 3.4-8.1

0 50 KILOMETERS

USGS SHAKEMAP : OKLAHOMA

SEP 3, 2016 12:02:44 UTC M 5.8 N36.43 W96.93 DEPTH: 5.6KM ID:US10006JXS

-98° -97° -96° -95°

35°

35.5°

36°

36.5°

37°

37.5°

38°

Map Version 9 Processed 2016-12-03 01:37:56 UTC 

Oklahoma City

Tulsa

Wichita

Norman

Edmond

Enid

Muskogee

Bartlesville

Bixby

Winfield

Arkansas City

Parsons

N
D

Advanced National Seismic System Progress to Date (2000–2016) 17

INSTRUMENTAL 

INTENSITY

PEAK VEL.(cm/s)

PEAK ACC.(%g)

POTENTIAL 

DAMAGE

PERCEIVED 

SHAKING Not felt Weak Light Moderate Strong Very strong Severe Violent Extreme

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

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

<0.07 0.4 11 22 43 83 >160

<0.1 .5 2.4 6.7 13 24 44 83 >156

1.9 5.8

-123° -122°

37.5°

38°

38.5°

39°

Map Version 31 Processed 2015-05-18 03:14:56 PM PDT

CISN SHAKEMAP : 6.3 KM (3.9 MI) NW OF AMERICAN CANYON, CA

AUG 24, 2014 03:20:44 AM PDT M 6.0 N38.22 W122.31 DEPTH: 11.2KM ID:72282711

N

San Francisco

Sacramento

Stockton

Fremont

Santa Rosa

Vallejo

Vacaville

Roseville

Tracy

San Rafael

Lodi

Cloverdale

0 50 KILOMETERS
18 Advanced National Seismic System—Current Status, Development Opportunities, and Priorities for 2017–2027

• Did-You-Feel-It? (DYFI). DYFI (sidebar 8, p. 20) 

provides a means for people feeling an earthquake to 

report their experience at an ANSS website, which 

enables crowd sourcing to augment the body of scientific 

information. These responses from citizen scientists 

produce a geographic view of earthquake shaking 

intensity as humanly experienced. To date, almost 

4 million DYFI reports have been submitted and more 

than 27,000 earthquakes have generated DYFI reports.

• ANSS Comprehensive Catalog. An important task is 

compiling an earthquake record based on standardized 

analysis using data from validated sources. The ANSS 

produces such a comprehensive earthquake catalog—

ComCat—using ANSS networks. ComCat is continuously 

updated in real time and is available via the web for 

customized data searches.

• Earthquake Source Characteristics. Following 

significant earthquakes, ANSS networks routinely 

produce scientific information about the earthquake’s 

rupture. Seismologists estimate the orientation of the 

fault, the length of the fault, and the distribution of slip 

along the fault. These results are used to better constrain 

the shaking estimates produced by ShakeMap and 

consequently improve the estimates of fatalities and 

economic loss produced by PAGER.

• Center for Engineering Strong Motion Data 

(CESMD). CESMD products provide ground motion 

and structural response data to the earthquake engineering 

community that are essential to improve the resilience 

of our Nation’s buildings and infrastructure by providing 

data that directly serve engineering applications 

and research. 

Advanced National Seismic System 

Development Opportunities (2017–2027)

Although the ANSS has made considerable progress 

toward full implementation, since 2000, the development of 

earthquake monitoring capabilities has not kept pace with 

the nation’s increasing earthquake risk owing to urban and 

economic development, with technological advances, or with 

opportunities to deliver improved products and services. The 

ANSS has significant capacity to grow in order to improve 

earthquake safety, to support response and recovery, and to 

achieve greater resilience nationwide. 

The specific opportunities and priorities for ANSS 

growth in the next decade, listed thematically, are described 

below. As described in the appendix, additional resources will 

be required to fully achieve the ANSS mission and implement 

these opportunities, which are essential to ensure ANSS 

readiness in an earthquake crisis, advance earthquake safety 

in urban areas, and expand the observational database for 

earthquake risk reduction.

Ensuring Readiness in an Earthquake Crisis

The timeliness and usefulness of ANSS products have 

increased the expectations of its capabilities within government 

agencies, emergency responders, the public, and the engineering 

and scientific communities. However, with limited resources 

to sustain current ANSS capabilities, meeting the needs in 

an earthquake crisis represent a real challenge. To meet the 

expectations of the next decade, the ANSS must focus on 

improving the robustness of essential services and retaining 

capacity for future innovation. 

ANSS operations are complex, its staff is limited, and its 

aging and incomplete infrastructure is expensive to maintain 

and replace. Should a regional seismic network be incapacitated 

in a crisis, the NEIC can step in to “back up” that network, but 

the resulting products would be degraded and suboptimal. 

The Earthquake Notification Service needs hardening to ensure 

more robust delivery of messages. Improvements are needed 

so that data are posted more quickly to the CESMD. More 

work is needed to achieve greater utilization of ShakeCast, 

which is underutilized even within Federal Government 

agencies. Conducting preemptive “stress tests” of national 

and regional elements would help to identify weaknesses 

and likely failure points. Based on the results of these tests, 

resources could be invested to train and supplement personnel, 

harden communications and analysis center operations, and 

improve backup for all critical components. Such strengthening 

of ANSS is needed to ensure that the system is highly functional 

during a crisis. 
Advanced National Seismic System Development Opportunities (2017–2027) 19

7. Prompt Assessment of Global Earthquakes for

Response (PAGER) 

PAGER provides shaking and loss estimates following significant earthquakes anywhere in the world (see Wald and 

others, 2010). These estimates are generally available within 30 minutes and are updated as more information becomes available. 

Rapid estimates include the number of people and names of cities exposed to each shaking intensity level as well as the likely ranges 

of fatalities and economic losses. PAGER does not consider secondary effects such as landslides, liquefaction, and tsunami in loss 

estimates at this time.

An example Prompt 

Assessment of Global 

Earthquakes for Response 

(PAGER) alert from the 

August 2014 M6.0 American 

Canyon (South Napa), 

Calif., earthquake. In this 

example, the PAGER alert 

level is green for fatalities 

but orange for economic 

losses. Figure courtesy of 

the National Earthquake 

Information Center.

Advanced National Seismic System Development Opportunities (2017–2027) 19

POTENTIAL 

DAMAGE

PERCEIVED SHAKING Not felt Weak Light Moderate Strong Very strong Severe Violent Extreme

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

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

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

--* 1,521k* 6,255k* 736k 180k 106k 15k 0 0

N

123.5° 123° 122.5° 121.5°

38.5°

37.5°

38° 

122°

Event ID: nc72282711

1%

1 100 10,000

10 1,000

USD (Millions)

100,000

6% 21% 35% 27%

9% 1%

76%

1 100 10,000

10 1,000

Fatalities

100,000

24%

Orange alert level for economic losses.

Significant damage is likely and the disaster is

potentially widespread. Estimated economic

losses are less than 1% of GDP of the United

States. Past events with this alert level have

required a regional or national level response.

Green alert level for shaking-related fatalities.

There is a low likelihood of casualties.

Structures:

Overall, the population in this region resides

in structures that are highly resistant to

earthquake shaking, though some vulnerable

structures exist.

Recent earthquakes in this area have caused

secondary hazards such as landslides and

liquefaction that might have contributed to losses.

From GeoNames.org

MMI City Population

VII Napa

Napa

77k

VII American Canyon 19k

VI Sonoma 11k

VI Vallejo

Vallejo

116k

VI Yountville 3k

VI El Verano 4k

IV Sacramento 466k

IV Stockton 292k

IV San Francisco

San Francisco

805k

IV Oakland 391k

III Fremont

Fremont

214k

Estimated Fatalities Estimated Economic Losses

Estimated Population Exposed to Earthquake Shaking

Population Exposure

Selected City Exposure

ESTIMATED POPULATION

EXPOSURE (k = x1000)

ESTIMATED MODIFIED

MERCALLI INTENSITY

Resistant

Structures

Vulnerable

Structures

*Estimated exposure only includes population within the map area.

PAGER content is automatically generated, and only considers losses due to structural Bold cities appear on map (k = x1000)

damage. Limitations of input data, shaking estimates, and loss models may add uncertainty.

http://earthquake.usgs.gov/pager

PAGER

Version 4

Created: 33 minutes, 25 seconds after earthquake

Historical Earthquakes (with MMI levels):

Date

(UTC)

Dist.

(km)

Mag. Max

MMI(#)

Shaking

Deaths

1983-05-02 284 5.7 VIII(1k) 0

1980-01-24 76 5.8 VII(31k) 1

1989-10-18 132 6.9 IX(3k) 62

population per ~1 sq. km from Landscan

M 6.0, 6.7 km (4.2 mi) NW of American Canyon, CA

Earthquake

Shaking

Orange

Alert

Origin Time: Sun 2014–08–24 10:20:44 UTC (03:20:44 local)

Location: 38.21 N 122.32 W Depth: 10 km ° °
20 Advanced National Seismic System—Current Status, Development Opportunities, and Priorities for 2017–2027

8. Did-You-Feel-It?

Did-You-Feel-It? (DYFI) is a tool by which people may report their experiences of an earthquake, 

providing crowd-sourced information to supplement instrumental data. DYFI is an important product of 

the Advanced National Seismic System and DYFI-based shaking intensity information is used to improve 

ShakeMap and PAGER products.

Maps showing cumulative Did-You-Feel-It? (DYFI) reports in the United States from 1991 through 2015, which illustrates the national use 

of the DYFI tool. Maps courtesy of the National Earthquake Information Center.

Did You Feel It? (intensity)

II

III

IV

V

VI

VII

VIII

IX

Significant event

EXPLANATION

_

_

_

_

_

_

_

_

_

_

_

_

_

_

_

_

_

_

_

_

_

_

_

_

_ __

_

_

_

_

_

_

ALASKA

HAWAII

PUERTO RICO
Advanced National Seismic System Development Opportunities (2017–2027) 21

An example of a DYFI community shaking intensity map for the 2011 M5.8 Mineral, Va., earthquake. Over 122,000 people 

provided responses that were used in generating this earthquake’s DYFI map. The earthquake was felt as far south as Georgia 

and as far north as Canada. Open circles in the northern part of the map denote Canadian cities color-coded to DYFI intensity 

legend and with circle size proportional to city population. Maps courtesy of the National Earthquake Information Center.

DAMAGE

SHAKING Not felt Weak Light Moderate Strong Very strong Severe Violent Extreme

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

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

City size

<10,000

10,000+

100,000+

2M+

EXPLANATION

N

New York

Chicago

Philadelphia

Detroit

Indianapolis

Baltimore

Charlotte

Milwaukee

Boston

Nashville

Cleveland

Virginia Beach

Atlanta

Raleigh

Cincinnati

Buffalo

Lexington

Montgomery

Richmond

Providence

Jacksonville

0 200 KILOMETERS

85° W 80° W 75° W 70° W

35° N

40° N

45° N

Processed 2011-08-24 11:12:51 PM PDT

122476 responses in 8269 ZIP codes and 159 cities (Max CDI = VII)

USGS COMMUNITY INTERNET INTENSITY MAP : VIRGINIA

AUG 23 2011 01:51:04 PM LOCAL 37.936N 77.933W M5.8 DEPTH: 6 KM ID:SE082311A
22 Advanced National Seismic System—Current Status, Development Opportunities, and Priorities for 2017–2027

Advancing Earthquake Safety in Urban Areas

The ANSS can better ensure public safety and effective 

societal response during earthquakes through expanded 

instrumentation in and around urban areas to enable earthquake 

early warning, high-resolution assessments of earthquake 

shaking intensity and associated damage potential for emergency 

response and management of critical facilities and lifelines, 

and aftershock forecasting. For example, ANSS situational 

awareness products such as ShakeMap or ShakeCast are used 

by emergency responders immediately after an earthquake to 

conduct damage assessment of critical infrastructure (such as 

hospitals, bridges, water systems), to inform decisions to 

evacuate of areas vulnerable to dam collapse, to prompt actions 

by utility operators, or to help guide the design of search and 

rescue operations. 

Developing Earthquake Early Warning Systems

If seismic and geodetic data to determine the size and 

location of an earthquake are rapidly available and quickly 

analyzed, a warning of imminent shaking can be broadcast 

to areas not yet shaken. Earthquake early warning (EEW) 

(sidebar 9, p. 23) enables protective actions before the damaging 

shaking arrives: people can take protective actions, such as 

“Drop, cover, and hold on,” and systems can make automated 

responses, such as the slowing or stopping of trains. The 

technical concepts to provide seconds to minutes of warning 

of expected ground shaking have been established. The 

immediate goal of the ANSS is to build and operate the 

“ShakeAlert” EEW system along the west coast of the 

United States (Given and others, 2014), with subsequent 

expansion to other regions. Significant additional resources 

are needed to raise the west coast EEW system to a fully 

operational level. At the Federal level, the USGS is tasked with 

developing an EEW system in the United States, as codified 

in the Earthquake Hazards Reduction Act of 1977 (42 U.S.C. 

7701 et seq.).

Developing High-Resolution Damage and 

Impact Assessments for Urban Areas

Because the intensity of shaking in a major earthquake 

can vary dramatically over small distances, the ANSS needs to 

increase the number of strong-motion instruments in high- to 

moderate-risk urban areas. For example, in the Loma Prieta 

earthquake, the Marina District of San Francisco and certain 

parts of Oakland experienced amplified shaking that caused 

much more extensive damage and fatalities as compared to 

other regions. Dense, urban strong-motion networks are needed 

to measure the variation in shaking across different geologic 

conditions to produce rapid high-resolution damage and impact 

assessments following an earthquake. This information can 

be disseminated within minutes via ShakeMap and CESMD 

products to provide situational awareness to aid the emergency 

response, save lives, and reduce disruption. Such data are also 

valuable for informing decisions on rebuilding and improving

building codes, earthquake-resistant design, and construction 

practices after an earthquake, because dense networks ensure 

that damaged structures have nearby reference seismic records 

on which to base an engineering analysis. In addition to 

free-field stations, sensors in buildings would support more 

informed assessment of building damage and decisions on 

re-occupancy and functionality following an earthquake. 

Developing High-Resolution Damage 

and Impact Assessments for Critical Facilities 

and Lifelines

An earthquake disaster can be compounded by damage to 

critical facilities and lifelines, which are vital to the function 

of a community. The same justification for high-resolution 

monitoring of shaking in urban areas can be applied to critical 

facilities, lifelines, and infrastructure elements and nodes. The 

ANSS needs to increase the number of instrumented critical 

facilities and lifelines. High-resolution information is essential 

for the rapid determination of infrastructure damage, response 

actions, and the restoration of services. The actual shaking 

levels recorded at instrumented critical facilities and lifelines 

would be disseminated through ShakeCast. ANSS work with 

the VA provides an example of this type of application. In 1971, 

several hospitals collapsed in the M6.6 San Fernando, Calif., 

earthquake: since then, the VA and the USGS have collaborated 

to install instrumentation in VA medical centers in high-risk 

regions and have built the capability to rapidly assess structural 

health after an earthquake. 
9. Earthquake Early Warning 

Earthquake early warning systems, like the ShakeAlert system currently in development on the west 

coast of the United States, work because the warning can be transmitted almost instantaneously, while 

the damaging shaking waves from the earthquake travel through the Earth at speeds of a few miles per 

second. The faster but weaker P-waves trip a sensor, causing alerts to be sent out before the arrival of 

the slower but stronger S-waves and surface waves, as shown in the image below. 

Epicenter

In an earthquake, a rupturing 

fault sends out different types of 

waves. The fast-moving P-wave 

is first to arrive, but damage is 

caused by the slower S-waves 

and later-arriving surface waves.

Sensors detect the P-wave and 

immediately transmit data to an 

earthquake alert center where the 

location and size of the quake are 

determined and updated as more 

data become available. 

A message from the alert center 

is immediately transmitted to your 

computer or mobile phone, which 

calculates the expected intensity 

and arrival time of shaking at your 

location.

Sensors positioned about 

6-12 miles apart Earthquake

alert center Sensors

S-wave P-wave

Fault

Epicenter

Seismologists are testing an earthquake early warning system similar to one being used in 

Japan that can send out warnings of earthquakes to your computer or mobile device seconds 

to minutes in advance. Here’s how the system works:

EARTHQUAKE EARLY WARNING BASICS

1. 2. 3.

Advanced National Seismic System Development Opportunities (2017–2027) 23

U.S. Geological Survey image showing the basic concepts of earthquake early warning systems, such as ShakeAlert from Burkett and 

others (2014).
24 Advanced National Seismic System—Current Status, Development Opportunities, and Priorities for 2017–2027

Implementing Aftershock Forecasting 

as a National Capability

After a major earthquake, the possibilities of significant 

aftershocks or even stronger events are continuing hazards 

that threaten a community. Public fear is high and emergency 

responders are at risk. The ANSS aims to provide short-term 

forecasts of earthquake aftershock activity for time periods of 

hours, days, months, and years. Authoritative, time-dependent 

information regarding the likelihood of aftershocks and 

additional large events is needed to help communities and 

individuals prepare. As recommended by the National 

Earthquake Prediction Evaluation Council in 2016, the ANSS 

will work to incorporate aftershock forecasts into routine 

seismic analysis and public notifications. To highlight the 

danger of earthquake sequences, note that the New Madrid 

earthquakes of 1811–12 in the central United States consisted 

of three greater-than-M7 earthquakes occurring over a period 

of less than 2 months. 

Expanding the Observational Database for 

Earthquake Risk Reduction

Most advances in earthquake science and earthquake 

engineering research for risk reduction are achieved through 

access to reliable and comprehensive data resources. Continued 

improvement of our understanding of the causes and effects of 

earthquakes and their impacts on manmade structures will be 

heavily dependent on the scope of ANSS data. 

Monitoring Data for Determining the 

Seismic Response of Structures and Lifelines

Each major earthquake provides a new learning opportunity 

for earthquake engineers, who use ANSS information to improve 

the nation’s built environment. The ANSS deploys seismic 

instruments within representative structures to address 

unresolved issues in seismic design, retrofitting practices, and 

building codes as well as to provide validation of experimental 

and simulation research. When a major earthquake occurs, 

instrumented buildings provide data to understand the dynamics 

of structures and soil-structure interaction. It is important to 

measure how design and retrofit concepts respond to actual 

earthquake shaking so that they can be more generally adopted, 

or adapted as warranted. For example, after the Northridge 

earthquake, engineers were surprised by the widespread 

damage to moment-resisting steel-frame buildings, leading to 

improvements in design and construction of this building 

type and improved building codes. The ANSS inventory of 

instrumented structures should be increased to better align it 

with the characteristics of recent urban development (such 

as tall residential buildings) and hardened infrastructure for 

water, sewer, gas, electric, and major transportation projects. 

More instrumented buildings would help inform and refine 

policies being put in place in various cities for hazardous 

existing buildings (such as nonductile concrete buildings, 

soft-story wood frame buildings, and potentially deficient tall 

steel-frame buildings built in the 1950s through 1970s).

Developing Comprehensive Assessments of 

Human-Induced Earthquake Hazard and Risk

It has long been understood that earthquakes can be 

induced by certain human activities: impoundment of reservoirs, 

surface and underground mining, withdrawal of fluids and gases 

from the subsurface, and injection of fluids into underground 

formations. Since 2009, there has been a dramatic increase 

in seismic activity in some States in the central and eastern 

United States, including Arkansas, Colorado, Kansas, Ohio, 

Oklahoma, and Texas (sidebar 10, p. 25). Most of this increase 

is believed to be caused by the deep underground disposal of 

waste water resulting from oil and gas recovery processes (for 

example, Weingarten and others, 2015). The ANSS is making 

a significant contribution to the study of induced seismicity 

through cooperation with State agencies and networks, 

deployment of portable seismometers to the active areas, and 

special analyses of data from portable and permanent stations. 

The ANSS provides the infrastructure so that data from these 

State networks can be disseminated and integrated with ANSS 

participating regional seismic networks. This opportunity 

would increase ANSS efforts in order to provide the scientific 

understanding and products needed by regulatory agencies as 

they work to reduce the seismic activity and manage the 

hazard. These efforts would also support the assessment of 

the natural earthquake hazard in the central and eastern 

United States and also may reveal new information about the 

fundamental nature of stress in the Earth’s crust.
Advanced National Seismic System Development Opportunities (2017–2027) 25

10. Induced Seismicity 

The number of earthquakes in the central and eastern United States has dramatically increased over the 

past decade, as shown in the figure on the right. Most of this recent increase is believed to be induced 

seismicity caused by the deep underground disposal of waste water resulting from oil and gas recovery 

processes (see for example, Weingarten and others, 2015).

Map and graph showing the locations and cumulative number of earthquakes with a magnitude of 3.0 or greater 

in the central United States recorded from 1973 through 2016. The rate of earthquake occurrence increased sharply 

beginning in 2009; there were 855 such earthquakes from 1973 through 2008 (locations shown as purple dots) and 

2,897 earthquakes from 2009 through 2016 (locations shown as orange-to-red dots). Figure courtesy of Justin Rubinstein.

1975 1980 1985 1990 1995 2000 2005 2010 2015

0

200

400

600

800

1000

1200

Number of earthquakes of magnitude 3.0 or greater

Year

 855 >−M3 Earthquakes 1973–2008

EXPLANATION

2,897 >−M3 Earthquakes 2009–2016
26 Advanced National Seismic System—Current Status, Development Opportunities, and Priorities for 2017–2027

Incorporating Geodetic Data into Rapid, 

Comprehensive Earthquake Impact Assessments 

The incorporation of geodetic data is a new element for 

the ANSS: the earthquake early warning implementation plan 

(Given and others, 2014) relies on real-time GNSS stations as 

an essential component of the system. Advancing the use of 

geodetic data is needed to help rapidly characterize the surface 

or ocean bottom deformation of large magnitude events, such 

as ruptures along the Cascadia and Alaska-Aleutian subduction 

zones. Information from both seismic and geodetic data will 

lead to more accurate understanding of the earthquake source, 

thereby improving earthquake early warnings, ShakeMaps, 

and impact assessments. Challenges lie in developing the 

analytical techniques for joint interpretation of seismic and 

geodetic data and in further development of real-time geodetic 

networks and data-management structure. 

Improving Coverage in the Central and 

Eastern United States

Earthquake risk is significant in the central and eastern 

United States. Severe losses can occur from even moderate-size 

earthquakes close to major metropolitan areas and (or) critical 

facilities, owing to the more vulnerable building inventory and 

because of stronger shaking over wider areas for a given 

magnitude (an effect of the generally lower attenuation1 of 

seismic waves and higher earthquake stress drops2 in this 

region). However, the ground-motion database is too sparse 

and more ANSS instrumentation is needed to capture close-in 

recordings of major earthquakes—such as the 2011 M5.8 

Mineral, Va., earthquake—to better quantify the hazard and 

1

Seismic waves decay with distance owing to attenuation and geometrical 

spreading. Attenuation is a function of the Earth’s material properties, which 

2

Stress drop is a property of an earthquake source. Earthquakes with higher 

stress drops have greater radiated seismic energy.

improve the National Seismic Hazard Model. The NRC shares 

an interest in collecting more high-quality ground-motion 

data for the design and construction of nuclear facilities, as do 

other Federal agencies. The USGS has been working with the 

Office of Science and Technology Policy, the NSF, the Office 

of Management and Budget, the Department of Energy, and 

the NRC to make 158 permanent EarthScope Transportable 

Array stations in the central and eastern United States. An 

ANSS priority is to be able to assume the operation of these 

stations and integrate their data into analysis centers, as well 

as to continue to expand this region’s monitoring infrastructure.

Expanding Coverage in Areas of 

High Seismic Hazard

Many regions with high hazard, particularly in Alaska and 

the Intermountain West, need expanded ANSS instrumentation, 

including the areas within the Alaska-Aleutian subduction 

zone and the Intermountain West (areas struck by the 1983 

M6.9 Borah Peak earthquake in Idaho, the 1959 M7.3 

Hebgen Lake earthquake in Montana, the 1934 M6.6 

Hansel Valley earthquake in Utah, and the 2008 M6.0 Wells 

earthquake in Nevada). For all of these past earthquakes, 

close-in on-scale instrumental records were lacking or limited 

to one or two recordings. Similarly, improved monitoring is 

needed of earthquake swarms that could escalate into larger 

earthquakes, such as the recent swarms near the 1983 Borah 

Peak rupture and near Sheldon, Nevada. Capturing ground 

motions from large earthquakes would greatly improve the 

understanding of ground-motion prediction equations and 

site amplification as well as how fault segments interact and 

fault rupture initiates and propagates. Improving earthquake 

monitoring in the State of Alaska would provide data to support 

energy and natural resources development and to improve 

understanding of the Alaska-Aleutian subduction zone.
Conclusions

The ANSS began in 2000 as a bold endeavor to change 

earthquake monitoring in the United States. Remarkable 

progress has been made toward building a state-of-the-art 

system. As a result of investments made in the ANSS and the 

forging of strong partnerships, any earthquake of significance 

in the United States or anywhere in the world can now be 

rapidly characterized by a suite of products, providing situational 

awareness during times of crisis. ANSS monitoring serves 

scientific research and earthquake engineering needs. 

But challenges lie ahead, and the full potential of ANSS 

is not yet realized. After 16 years, the ANSS is less than 

halfway completed and its capabilities have not kept pace 

with the nation’s increasing earthquake risk. As described 

previously, the ANSS has the capacity to grow in order to 

improve earthquake safety and to support response and 

recovery and resilience nationwide. ANSS priorities for the 

next decade are to ensure ANSS readiness in an earthquake 

crisis, advance earthquake safety in urban areas, and expand 

the observational database for earthquake risk reduction. The 

ANSS community has achieved progress through their spirit 

of hard work, cooperation, innovation, and dedication to 

public service and safety. They will meet the challenges in 

the same spirit. 

Conclusions 27
28 Advanced National Seismic System—Current Status, Development Opportunities, and Priorities for 2017–2027

References Cited

ANSS Structural Instrumentation Guideline Committee, 2005, 

Guideline for ANSS seismic monitoring of engineered civil 

systems—Version 1.0: U.S. Geological Survey Open-File 

Report 2005–1039, 49 p. [Also available at https://pubs.

er.usgs.gov/publication/ofr20051039.]

ANSS Technical Implementation Committee, 2002, Technical 

guidelines for the implementation of the Advanced National 

Seismic System—Version 1.0: U.S. Geological Survey 

Open-File Report 2002–92, 92 p. [Also available at https://

pubs.er.usgs.gov/publication/ofr0292.]

Burkett, E.R., Given, D.G., and Jones, L.M., 2014, ShakeAlert— 

An earthquake early warning system for the United States 

West Coast (ver. 1.2, February 2017): U.S. Geological Survey 

Fact Sheet 2014–3083, 4 p., accessed March 8, 2017, at 

https://doi.org/10.3133/fs20143083.

Given, D.D., Cochran, E.S., Heaton, T., Hauksson, E., Allen, 

R., Hellweg, P., Vidale, J., and Bodin, P., 2014, Technical 

implementation plan for the ShakeAlert production 

system—An earthquake early warning system for the 

West Coast of the United States: U.S. Geological Survey 

Open-File Report 2014–1097, 25 p., accessed March 8, 2017, 

at http://dx.doi.org/10.3133/ofr20141097.

Jaiswal, K.S., Bausch, Douglas, Chen, Rui, Bouabid, Jahwar, 

and Seligson, Hope, 2015, Estimating annualized earthquake 

losses for the conterminous United States: Earthquake Spectra, 

v. 31, no. S1, p. S221–S243, accessed March 8, 2017, at 

http://dx.doi.org/10.1193/010915EQS005M.

Jaiswal, K.S., Petersen, M.D., Rukstales, K., and Leith, W.S., 

2015, Earthquake shaking hazard estimates and exposure 

changes in the conterminous United States: Earthquake 

Spectra, v. 31, no. S1, p. S201–S220, accessed March 8, 2017, 

at http://dx.doi.org/10.1193/111814EQS195M.

National Research Council, 2006, Improved seismic 

monitoring—Improved decision-making; Assessing the 

value of reduced uncertainty: Washington, D.C., The 

National Academies Press, 166 p. plus appendixes, accessed 

March 8, 2017, at https://doi.org/10.17226/11327.

Petersen, M.D., Moschetti, M.P., Powers, P.M., Mueller, C.S., 

Haller, K.M., Frankel, A.D., Zeng, Y., Rezaeian, S., 

Harmsen, S.C., Boyd, O.S., Field, N., Chen, R., Rukstales, 

K.S., Luco, N., Wheeler, R.L., Williams, R.A., and Olsen, 

A.H., 2014, Documentation for the 2014 update of the 

United States national seismic hazard maps: U.S. Geological 

Survey Open-File Report 2014–1091, 243 p., accessed 

March 8, 2017, at http://dx.doi.org/10.3133/ofr20141091. 

U.S. Geological Survey, 1999, An assessment of seismic 

monitoring in the United States; Requirement for an 

Advanced National Seismic System: U.S. Geological 

Survey Circular 1188, 55 p. [Also available at https://pubs.

er.usgs.gov/publication/cir1188.]

Wald, D.J., Jaiswal, K.S., Marano, K.D., Bausch, D.B., 

and Hearne, M.G., 2010, PAGER—Rapid assessment 

of an earthquake’s impact (revised November 2011): 

U.S. Geological Survey Fact Sheet 2010–3036, 4 p., 

accessed March 8, 2017, at https://pubs.usgs.gov/

fs/2010/3036/.

Weingarten, M., Ge, S., Godt, J.W., Bekins, B.A., and 

Rubinstein, J.L., 2015, High-rate injection is associated 

with the increase in U.S. mid-continent seismicity: Science, 

v. 348, no. 6241, p. 1336–1340, accessed March 8, 2017, 

at http://dx.doi.org/10.1126/science.aab1345.
Appendix: Planning Considerations for 2017–2027 29

Appendix: Planning Considerations for 2017–2027

The opportunities cited in this circular set the framework for ANSS planning into the future. 

Useful plans must be practical, taking into account the funding needed in addition to fulfilling 

current operational responsibilities. This appendix reviews the current financial status of the 

ANSS, the estimated resources needed for its development opportunities and priorities, and the 

expected outcomes. 

Current Resources and Responsibilities 

Total funding for the ANSS from the USGS Earthquake Hazards Program in fiscal year 

(FY) 2016 was $30.8 million, including $8.2 million for the implementation of earthquake 

early warning (EEW) on the west coast. This funding provides the support for the ANSS to 

meet its responsibilities in the activities listed below.

• Eleven regional seismic networks operated by academic institutions. Some of these 

networks are operated jointly with the USGS.

• The “ANSS backbone” National Seismic Network, providing uniform coverage 

nationwide in areas not covered by regional networks.

• The National Earthquake Information Center (NEIC), a 24/7 data analysis center for 

national and worldwide earthquakes.

• The National Strong Motion Project providing data on very strong earthquake shaking, 

both on the ground and in buildings, for earthquake-resistant engineering research and 

design and for ShakeMap.

• Continuing development of ShakeAlert EEW operational capability on the west coast.

• ANSS management and organizational support.

• Support of data centers for archiving and distribution.

• Portable instrument cache for temporary deployments.

With the exception of funding for the EEW development effort, all of the USGS ANSS 

funding in FY 2016 was applied to ongoing operations, maintenance, and management. Thus, 

new funding is needed to fully realize the opportunities listed in this circular. 

Development Needs and Outcomes for 2017–2027

The ANSS planning structure for the next decade is based on three major opportunities 

and their associated priorities. Notional budgets to advance each opportunity are given below, 

in 2016 dollars. Implementing all of the opportunities would require a substantial increase in the 

USGS annual budget for the ANSS, which was $30.8 million in FY 2016, or obtaining additional 

contributions from non-USGS supporters of the ANSS. 

Opportunity A. Ensuring Readiness in an Earthquake Crisis

Resources needed: Moderate ($5 million per year). Resources would address practical 

issues, such as providing adequate staffing levels, hardening communications, supporting 

the amortization and replacement of aging equipment, improving software, deploying better 

backup capabilities, and improving quality control by performance tracking. 

Result: Users will have greater assurance that they will receive the high-quality ANSS 

products and services in an earthquake crisis, leading to improved response and recovery. 

ANSS systems and procedures will be tested under realistic earthquake crisis conditions and 

hardened to be sufficiently robust.
30 Advanced National Seismic System—Current Status, Development Opportunities, and Priorities for 2017–2027

Opportunity B. Advancing Earthquake Safety in Urban Areas

Priority B.1. Developing Earthquake Early Warning Systems

Resources needed: Substantial. An EEW planning document (Given and others, 2014; 

USGS Open-File Report 2014–1097) estimates that a capital investment of $39 million and an 

ongoing $16.4 million per year would be needed to operate and maintain a complete EEW

system along the west coast (note that congressionally appropriated EEW funding grew to 

$8.2 million by FY 2016, which is about one-half of the needed yearly funding). This funding 

would be in addition to the regular ANSS and State support of west coast networks. Additional 

funding would be needed to expand EEW capabilities to other regions in the United States. 

Geodetic data would be integrated along with seismic data into the ShakeAlert earthquake 

early warning system. Development of geodetic applications is dependent on long-term support 

for and improvements to real-time geodetic network operations, so that they can be added as 

participants in the ANSS. 

Result: A fully operational ShakeAlert earthquake early warning system that reliably issues 

public warnings of imminent ground shaking within a few to tens of seconds of an earthquake 

onset on the west coast of the United States.

Priority B.2. Developing High-Resolution Damage and Impacts Assessment for Urban Areas

Resources needed: Moderate ($5 million per year). Coverage of dense strong-motion 

instruments in high- to moderate-risk urban areas would be expanded. The ANSS would 

work with industry to develop a low-cost sensor package to meet this objective, following on 

from the previous, successful NetQuakes sensor project. 

Result: High-resolution information on the ground shaking intensity and variation will 

be available across select urban areas following an earthquake. Having such information will 

support effective earthquake response and rebuilding and advances in earthquake engineering 

and improved hazard assessments. Engineering methods now exist that use seismic records 

as part of post-earthquake inspections to assess the safety and functionality of a structure, and 

high-resolution information would support more frequent use of these 

sophisticated methods.

Priority B.3. Developing High-Resolution Damage and Impact Assessments for 

Critical Facilities and Lifelines

Resources needed: Moderate ($3 million per year). The ANSS would work with regions 

to identify the highest priority targets for instrumentation and to establish a deployment strategy 

with facility owners and lifeline managers. ANSS costs also include instrumenting facilities, 

collecting and analyzing the data, and pushing results to operators. This effort would build on 

the existing ShakeCast service. As in priority B.2, a next-generation, low-cost sensor technology 

would be developed. 

Result: Ground-shaking information that will allow more rapid restoration of vital services to 

a community when a major earthquake strikes. For example, State Departments of Transportation 

(DOTs) may oversee hundreds to thousands of bridges and overpasses. Several DOTs already 

use ShakeCast to obtain automatic notification about which facilities in their inventory have 

possibly been damaged in an earthquake. ShakeCast output will help a DOT to set priorities for 

traffic rerouting, closures, and inspections, illustrating how timely and accurate ANSS data is 

important to ensure public safety and to reestablish critical functions.
Appendix: Planning Considerations for 2017–2027 31

Priority B.4. Implementing Aftershock Forecasting as a National Capability 

Resources needed: Moderate ($2 million per year). Concepts and procedures have been 

developed for aftershock forecasting. Additional funds would support personnel to implement 

the forecast procedures to run in real time as a part of the NEIC, as well as for research and 

development in the field and for end-user education. Because forecasts would be built from 

the ANSS Comprehensive Catalog (ComCat), further enhancements of ComCat would be 

needed, including the completion of the loading of regional seismic network historic catalogs 

and the implementation of version control so that forecasts can be reproduced and methods can 

be improved by the scientific community.

Result: Routine notifications of aftershock likelihoods after significant earthquakes 

nationwide, calculated for time periods of hours, days, months, and years, to improve public 

awareness and readiness and to inform emergency managers.

Opportunity C. Expanding the Observational Database for Earthquake Risk 

Reduction

Priority C.1. Monitoring Data for Determining the Seismic Response of 

Structures and Lifelines

Resources needed: Moderate ($5 million per year). The ANSS would substantially 

increase the number of instrumented structures and lifelines, choosing targets to address specific 

unresolved issues in seismic design, retrofit practices, and building codes. The ANSS also 

would need support for data management and analysis. 

Result: A breadth and depth of data on the response of common types of structure design 

and construction to seismic shaking will be successfully recorded in a major earthquake, 

resulting in transformational breakthroughs in the engineering of cost-effective structures that 

perform well in an earthquake. 

Priority C.2. Developing Comprehensive Assessments of Human-Induced 

Earthquake Hazard and Risk

Resources needed: Moderate ($3 million per year). Resources would be used to support 

and cooperate with State networks and for ANSS data analysis and interpretation. To pinpoint the 

location and depth of induced seismicity sequences, portable arrays of closely spaced seismic 

instruments would also be needed in a study area. 

Result: Providing data needed to develop science-based protocols for activities that have 

potential to induce earthquakes, such as to achieve safe, deep underground disposal of waste 

water associated with oil and gas production. 

Priority C.3. Incorporating Geodetic Data into Rapid, Comprehensive 

Earthquake Impact Assessments 

Resources needed: Moderate (to be determined; note that some costs are included in 

priority B.1). Geodetic data would be integrated along with seismic data into ANSS products. 

Analytical techniques for joint interpretation of seismic and geodetic data and real-time geodetic 

networks and data-management structure will be developed and expanded. 

Result: More rapid and accurate characterization of earthquake sources for earthquake early 

warning and impact assessments; inclusion of real-time geodetic networks as ANSS participants.
32 Advanced National Seismic System—Current Status, Development Opportunities, and Priorities for 2017–2027

Priority C.4. Improving Coverage in the Central and Eastern United States

Resources needed: Moderate ($1.5 million per year). This funding would be used to 

support the operations of the Central and Eastern United States Network (CEUSN) seismic stations, 

to integrate data from these stations into existing data analysis procedures, and to further 

improve strong-motion station coverage. 

Result: Better monitoring and increased understanding of the seismic hazard and societal 

risk in the eastern half of the United States. Key data for improved ground-motion prediction 

equations will be successfully captured in a major earthquake, resulting in significantly reduced 

uncertainty in the National Seismic Hazard Model.

Priority C.5. Expanding Coverage in Areas of High Seismic Hazard

Resources needed: Moderate ($6 million per year). Funds would be used to deploy 

additional sensors and to support their operation in areas of high seismic hazard, in order to 

address gaps in coverage. Additional planning would be undertaken at the regional level.

Result: Better seismic monitoring and increased understanding of earthquakes at active 

faults, with particular focus on the Intermountain West and Alaska. 

Resources—Existing and Needed

Table A1 breaks down how much of the annual ANSS budget is currently being spent 

on activities that are broadly related to the above priorities as well as the augmentation to the 

annual resources that would be needed to fully implement these opportunities over the next 

decade (2017–2027). In addition to the annual resources to implement and maintain these 

opportunities, additional funds for capital investment into the earthquake early warning system 

on the west coast would also be needed.

Table A1. Advanced National Seismic System current annual resources and estimated augmentation to 

resource allocation needed to fully implement each development opportunity from 2017 to 2027.

[Abbreviations used: NA, not applicable; TBD, to be determined]

Development opportunity Annual resources (millions of 2016 dollars)

Code Short title Current Augmentation Total

A Earthquake crisis readiness 6.2 5.0 11.2

B.1 Earthquake early warning 8.2 8.2 16.4

B.2 Monitoring of urban areas 1.7 5.0 6.7

B.3 Monitoring of critical facilities 0.4 3.0 3.4

B.4 Forecasting aftershocks NA 2.0 2.0

C.1 Monitoring of structures 1.0 5.0 6.0

C.2 Monitoring of human-induced seismicity NA 3.0 3.0

C.3 Incorporating geodesy NA TBD TBD

C.4 Monitoring in central and eastern United 

States 

2.5 1.5 4.0

C.5 Monitoring of high-hazard areas 10.1 6.0 16.1

Other Management and coordination 0.7 0.5 1.2

Total 30.8 39.2 70.0

U.S. Geological Survey—Advanced National Seismic System Current Status, Development Opportunities, and Priorities for 2017–2027—Circular 1429, ver. 1.1

ISSN 1067-084X (print)

ISSN 2330-5703 (online)

https://doi.org/10.3133/cir1429