The Volcano Disaster Assistance Program—Helping to Save 

Lives Worldwide for More Than 30 Years

What do you do when a sleeping volcano roars back to 

life? For more than three decades, countries around the world 

have called upon the U.S. Geological Survey’s (USGS) Volcano 

Disaster Assistance Program (VDAP) to contribute expertise and 

equipment in times of crisis. Co-funded by the USGS and the 

U.S. Agency for International Development’s Office of U.S. Foreign Disaster Assistance (USAID/OFDA), VDAP has evolved 

and grown over the years, adding newly developed monitoring 

technologies, training and exchange programs, and eruption 

forecasting methodologies to greatly expand global capabilities 

that mitigate the impacts of volcanic hazards. These advances, in 

turn, strengthen the ability of the United States to respond to its 

own volcanic events.

VDAP was formed in 1986 in response to the devastating 

volcanic mudflow triggered by an eruption of Nevado del Ruiz 

volcano in Colombia. The mudflow destroyed the city of Armero 

on the night of November 13, 1985, killing more than 25,000 

people in the city and surrounding areas. Sadly, the tragedy was 

avoidable. Better education of the local population and clear 

communication between scientists and public officials could 

have allowed warnings to be received, understood, and acted 

upon prior to the disaster. 

VDAP strives to ensure that such a tragedy will never happen again. The program’s mission is to assist foreign partners, 

at their request, in volcano monitoring and empower them to 

take the lead in mitigating hazards at their country’s threatening volcanoes. Since 1986, team members have responded to 

over 70 major volcanic crises at more than 50 volcanoes and 

have strengthened response capacity in 12 countries. The VDAP 

team consists of approximately 20 geologists, geophysicists, and 

engineers, who are based out of the USGS Cascades Volcano 

Observatory in Vancouver, Washington. In 2016, VDAP was a 

finalist for the Samuel J. Heyman Service to America Medal for 

its work in improving volcano readiness and warning systems 

worldwide, helping countries to forecast eruptions, save lives, 

and reduce economic losses while enhancing America’s ability to 

respond to domestic volcanic events.

Cotopaxi erupting in 2015, southeast of Mejía 

Canton, Ecuador. Photograph copyright Henri 

Leduc, used with permission.

U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2017–3071

October 2017
VDAP Responses—Timely 

Warnings Save Lives 

Successful volcano responses rely 

on a combination of geophysical data, 

fieldwork, satellite observations, historical analysis, and effective communications. VDAP’s first major test was in 

1991 in the Philippines, where Mount 

Pinatubo threatened two U.S. military 

bases, as well as villages and towns 

around the volcano where hundreds of 

thousands of Filipinos lived. Swarms of 

earthquakes and small explosions spurred 

the Philippine Institute of Volcanology 

and Seismology to request assistance 

from VDAP. Together, they installed 

monitoring networks and estimated the 

potential for a cataclysmic eruption. 

With input from VDAP, the U.S. military opted to evacuate more than 15,000 

service personnel and dependents from 

Clark Air Force Base. Evacuations of 

nearby towns and villages saved between 

5,000 and 20,000 lives, and hundreds of 

millions of dollars worth of equipment 

was moved or protected before the volcano erupted just days later. 

On November 20, 2008, a volcanic 

mudflow swept through the town of Belalcázar, Colombia, as a result of eruptive 

activity on the nearby Nevado del Huila 

volcano. Prior on-site and remote support from VDAP allowed the Colombian 

Geological Survey to successfully avert 

a repeat of the earlier Armero tragedy 

through timely warnings, an aggressive 

education program, and effective communications. The local people were aware 

that the volcano posed a threat and were 

prepared to act; when the warning came, 

12,000 people evacuated the town at 

night. 

VDAP incorporates satellite imagery 

data as another form of monitoring shared 

with international partners. On October 

22, 2010, Indonesian scientists recognized that the frequently active Merapi 

volcano was experiencing earthquakes, 

gas emissions, and ground movements 

far more intense than usual. All available 

satellites were tasked to track growth of 

a lava dome at the volcano’s summit, and 

radar images penetrated the clouds that 

normally block visibility. The images 

helped VDAP’s partners at the Indonesian 

Center for Volcanology and Geologic 

Hazard Mitigation (CVGHM) to forecast 

deadly pyroclastic flows (scorching clouds 

of ash and rock particles that sweep 

downhill). On October 25, local authorities evacuated everyone living within 

10 kilometers (6 miles) of the summit. 

Twenty-three hours later, explosions sent 

the first searing pyroclastic flows as far as 

8 kilometers (5 miles) away. Over the following 10 days, VDAP and its Indonesian 

partners used satellite radar data to track 

the rapid extrusion of a lava dome at the 

summit and forecast the potential for an 

even larger event. On November 4, based 

on the remote sensing information and 

increased seismicity, CVGHM called for 

evacuations to be extended to 20 kilometers (12 miles) from the summit. Just 

hours later, the largest eruption at Merapi 

in 100 years generated pyroclastic flows 

and surges that decimated the landscape, 

Chile

Chaitén

Cerro Hudson

Mexico

Colima

Popocatépetl

Peru

Sabancaya

Ubinas

Ecuador

Reventador

Pichincha

Cotopaxi

Tungurahua

Sangay

Colombia

Nevado del Ruiz

Nevado del Huila

Galeras

Colombia - Ecuador

Chiles-Cerro Negro

Nicaragua

Telica

Cerro Negro

Momotombo

Concepción

Costa Rica

Poás

Turrialba

Guatemala

Santiaguito

Fuego

Pacaya

El Salvador

Santa Ana

San Miguel

Papua New Guinea

Manam

Garbuna

Pago

Rabaul Indonesia

Sinabung

Tangkubanperahu

Slamet

Dieng

Merapi

Raung

Tambora

Egon

Colo

Awu

Karangetang

Soputan

Lokon

Gamkonora

Gamalama

Philippines

Pinatubo

Taal

Mayon

Bulusan

Montserrat

Soufrière Hills

Cape Verde

Fogo

Saudi Arabia

Harrat Lunayyir

Tanzania

Ol Doinyo Lengai

Democratic Republic of the Congo

Nyirogongo

Mexico - Guatemala

Tacaná

Dominica

Morne Plat Pays

Sulu Range

San Cristóbal

Casita

Agung

Panama

Barú

World map with locations of volcanoes (red triangles) at which the Volcano Disaster Assistance Program (VDAP) has responded during the more than 

30 years since the program’s inception. 
Merapi volcano towers above this densely populated part of central 

Java (approximately 4 million people live nearby). In 2010, the decision 

to extend the evacuation zone from 10 kilometers (red dashed line) to 20 

kilometers (yellow dashed line) likely saved more than 10,000 lives when 

pyroclastic flows and floods (arrows) raced down the mountain. Base 

map data from Google, DigitalGlobe, 2017.

Workshops allow VDAP partners and collaborators to discuss best 

practices for a wide variety of situations. Here, VDAP staff and their 

Indonesian colleagues review seismic data to uncover earthquake 

characteristics that may be useful as eruption precursors. Photo by 

Jeffrey Marso, USGS.

VDAP Training Courses Offer 

Advanced Education Opportunities

Many countries simply lack the 

resources to educate and train scientists 

in the highly specialized tasks related 

to volcano monitoring and interpretation. VDAP champions a multi-pronged 

approach to bridge this knowledge gap. 

Travel grants bring scientists from around 

the world to the annual seven-week training course at the University of Hawaiʻi’s 

Center for the Study of Active Volcanoes 

on Hawaiʻi Island and in Vancouver, 

Washington. USGS staff and university 

partners serve as instructors and mentors for this unique training program. 

VDAP also sponsors focused workshops 

at home and abroad on topics including 

seismology, volcanic gas emissions, lahar 

(mudflow) modeling, hazards mapping, 

volcano deformation, remote sensing, and 

monitoring of crater lakes. USGS mentors 

also assist partners in writing and publishing their research so that they become 

the acknowledged experts for their local 

volcanoes.

traveling as far as 15 kilometers (9 miles) 

from the summit. The timely warnings 

and evacuations during the 2010 eruptions saved between 10,000 and 20,000 

lives.

Designing Equipment That Makes 

a Difference

To support worldwide volcano monitoring efforts, VDAP engineers assemble 

robust instruments that are simple to 

install, easy to maintain, and last for 

many years. Seismic and Global Positioning System (GPS) stations are positioned 

to detect and locate subtle earthquakes 

and ground movements that may signal 

an awakening volcano; they are designed 

to run on solar energy and relay their data 

in real time through low-power radios. 

Field engineers from partner agencies 

improve their skills in installing and 

maintaining the systems, either at home 

on their volcanoes, or during a visit to 

the Cascades Volcano Observatory. With 

experience, they can assist neighboring 

countries, enhancing VDAP’s secondary

goal of science diplomacy (see sidebar 

“Science as a Path to Diplomacy”).

VDAP also develops new systems 

to better and more frequently quantify 

the amounts and types of gas emitted 

from volcanoes, which are key indicators used to forecast volcano behavior. 

In the past, volcano scientists have had 

to make measurements in unsafe locations or fly through the volcanic plume 

in expensive helicopters or small aircraft. 

Today, VDAP scientists and engineers 

deploy scanning ultraviolet spectrometers 

to measure the volcanic output of sulfur 

dioxide—a key indicator of shallow 

magma—from afar. They also designed 

robust gas “sniffers” (called MultiGAS) 

to determine the ratio of sulfur dioxide to other key gases such as carbon 

dioxide, which reveals magma depth 

and the pathways by which gas reaches 

the surface. Both technologies can send 

data directly to the volcano observatory, 

without the need for frequent servicing of 

the instruments.
Installation of a telemetered, solar-powered scanning spectrometer in 2016 at Sinabung volcano in 

Sumatra, Indonesia, which has been continuously erupting since 2013. The instrument measures 

the amount of sulfur dioxide gas emitted from the volcano, which helps forecast volcanic activity. 

Photograph from Christoph Kern, USGS.

Exchanges Bring Emergency Responders Together

Without clear communication of hazards and risks, even the 

best science is insufficient to mitigate the threats from volcanic 

eruptions. Communications protocols are developed and refined 

in response to lessons learned at volcano crises around the world 

to ensure that emergency responders have the information they 

need to make wise decisions in time to make a difference. VDAP 

sponsors international exchanges where emergency managers, first responders, and land managers from the United States 

visit the sites of foreign volcano disasters and learn directly 

from their counterparts. Foreign counterparts, in turn, visit the 

United States and learn about the Incident Command System, 

multi-agency response plans, and how new monitoring tools are 

implemented into U.S. volcano observatory operations. Participants gain insights into the potential hazards and societal effects 

of volcanic events, and learn how to prepare for and respond to 

volcanic activity.

“When we went to Armero, something I’d seen and talked 

about, it really drove home the point of how similar the volcano 

of Mount Rainier is to the Nevado del Ruiz volcano and the 

hazards that both volcanoes share. And it really opened my eyes 

to the things the Colombians had done that worked really well 

and continue to this day to work really well, and the ways that 

we can improve our emergency systems to make sure that the 

tragedies that happened in Armero in 1985 are not replicated 

here at Mount Rainier.” 

—U.S. participant in the U.S.-Colombia binational exchange

Working Towards Better Eruption 

Forecasts

Having tools to monitor and evaluate the signals that volcanoes produce is 

necessary to make successful eruption 

and hazard forecasts. Besides its role in 

equipment development, VDAP creates 

and distributes software that is used 

globally, to assist volcano observatories 

with data assessment and interpretation. 

Yet, forecasts also depend upon understanding the outcomes of past activity at 

volcanoes around the world. Statistical 

models and supporting data serve as the 

tools required to make reliable forecasts. VDAP staff work with academic 

researchers, volcano observatories, 

and the body of scientific publications 

to create new tools to predict volcano 

behavior. In 2015, VDAP staff worked 

with Indonesian partners to estimate the 

likely duration of ongoing lava emissions at Sinabung volcano in northern 

Sumatra. Looking at global statistics 

and using a statistical model developed 

by university colleagues for similar 

eruptions, it was determined that activity 

at Sinabung would likely continue at 

least another three years. This forecast 

was instrumental in helping Indonesian 

authorities decide to permanently evacuate villages that were certain to remain 

in harm’s way in the future. 

 Another important VDAP role is 

to develop methods to interpret volcanic 

signals such as earthquakes. Through 

years of monitoring, VDAP seismologists have observed and documented 

patterns of earthquakes that occur prior 

to different kinds of volcanic activity. Their pioneering research is now 

incorporated into eruption forecasts, and 

helps seismologists around the world 

understand the causes and implications of commonly observed seismic 

phenomena. 

Fostering Best Practices

Each year, new lessons are learned 

during volcano crises around the world. 

VDAP works with volcano observatories 

to develop best practices for responses, 

communications, and alerts. Representatives meet periodically to discuss new 

insights, challenges, and developments. 

The USGS and the Istituto Nazionale di 

Geofisica e Vulcanologia in Italy work 

with VDAP and others to sponsor 

representatives from many countries that 

would otherwise lack funding to attend. 

VDAP also contributes to best-practices 

workshops at international volcano 

conferences, which bring together civil 

authorities, emergency responders, and 

volcanologists who specialize in dangerous volcanoes around the world.
Science as a Path to Diplomacy

By providing critical monitoring 

infrastructure, training, and ongoing 

consultation, VDAP aims to mitigate 

the risks posed by dangerous volcanoes. 

Close collaboration with international 

partners and their stakeholders inevitably 

results in secondary benefits: friendship, 

mutual trust, and goodwill. For example, 

after an unexpected eruption in 2008 at 

Chaitén volcano (Chile), VDAP assisted 

with the creation of a seismic network 

at this previously unmonitored volcano. 

This led to collaborative research on 

the volcano’s history and hazards, and 

a shared assessment project to prioritize 

needs for a national Chilean volcano 

monitoring system. VDAP scientists 

were called on to advise the government 

of Chile at the highest levels regarding 

volcano hazards monitoring and mitigation. The emergence of Chile’s volcano 

expertise and development of a robust 

volcano monitoring infrastructure followed, and has also fostered engagement 

with Argentinean geologists to understand risks from some of the dangerous 

volcanoes that straddle the Chile-Argentina border. By pursuing a program of 

science and public safety, VDAP fosters 

an environment that engenders international cooperation and diplomacy.

In May 2008, heavy rains remobilized ash laid down by the recent eruption of Chaitén volcano, in southern Chile. Though the town of Chaitén (visible 

in photo) had been evacuated, the floods rendered much of the town uninhabitable. All streets and the nearby airport were buried in 3–6 feet of mud, 

and the city harbor was destroyed. During the eruption aftermath, VDAP assisted Chile with equipment installation and later co-funded an international 

research effort to understand the history of the volcano and the effects of the eruption on the nearby environment. In addition, VDAP advised the 

government of Chile on a new national strategy to reduce risk from volcanic eruptions. Satellite photograph from NASA earth observatory through the 

FORMOSAT-2 satellite, May 26, 2008.

International Responses 

Contribute to Readiness at Home

VDAP strengthens the USGS Volcano Hazards Program and the Nation’s 

volcano disaster risk reduction capabilities in numerous ways. By participating 

in foreign volcano responses, USGS 

experts continually hone their skills, 

gaining the experience required to react 

to domestic eruptions. Equipment is 

continuously modified and improved 

to address new challenges encountered 

around the globe. Close collaboration 

with the suite of global volcano observatories results in the development of 

best practices that serve as templates for 

observatory protocols at home. Observations at erupting volcanoes provide 

insights that inform conceptual models of 

how volcanoes work, spark new research 

efforts, and spur improvements of equipment and forecasting methods that can 

then be applied in the United States. 

Through VDAP, the USGS earns credibility, worldwide recognition, and otherwise 

unobtainable experience. Yet VDAP 

would be an impossible dream without 

the infrastructure, personnel, and financial support provided by USAID/OFDA 

and USGS. More than 30 years after its 

inception, this unique program continues 

to be a critical element of global volcano 

disaster risk reduction.
ISSN 2327-6916 (print)

ISSN 2327-6932 (online)

https://doi.org/10.3133/fs20173071

For more information, contact the

Volcano Disaster Assistance Program 

U.S. Geological Survey 

David A. Johnston Cascades Volcano 

Observatory

1300 SE Cardinal Court, Bldg 10, Suite 100

Vancouver, Washington, 98683-9589

Phone: (360) 993-8900

By Jacob B. Lowenstern and David W. Ramsey

Edited by Katherine Jacques and

Claire Landowski

Design by Katherine Jacques and 

Vivian Nguyen

The city of Arequipa, Peru, is situated 

on the flanks of Misti volcano. VDAP 

works with the Instituto Geofísica 

del Perú and the Instituto Geológico, 

Minero y Metalúrgico to mitigate 

volcanic hazards in the volcanodense south of Peru. U.S. 

Geological Survey 

photograph by 

John Pallister.