Volcano SWAT Team
VDAP personnel unload
volcano monitoring equipment at Mt. Pinatubo, Philippines, June 1991.
After the eruption of Nevado del Ruiz killed more than 23,000 people in
Colombia in 1985, the U.S. Office of Foreign Disaster Assistance asked the U.S.
Geological Survey to design a program to help foreign governments cope with
volcano crises. The result was the Volcano Disaster Assistance Program, or
VDAP. Based at the Cascades Volcano Observatory in Vancouver, Washington, this
crack unit is standing by at all times, ready to lend a hand at the next
volcano showing signs of blowing up. NOVA asked VDAP's chief, volcanologist Dan
Miller, what it's like to be on the team.
NOVA: What do you consider VDAP's greatest success?
Miller: Without a doubt the 1991 eruption of Mt. Pinatubo in the Philippines,
which was the third-largest eruption of this century. When unrest began, VDAP's
little team of eight people, augmented by other scientists from the U.S.
Geological Survey and using funding and support from the U.S. Office of Foreign
Disaster Assistance, were invited to join scientists from the Philippine
Institute of Volcanology and Seismology. We worked together to install VDAP
monitoring equipment to build a volcano observatory on very short notice. Data
from the instruments were telemetered back to a location on Clark Air Base,
which is very close to Pinatubo.
The scientific team did an incredible job of interpreting the data coming in
and of understanding what was about to happen. They completed a preliminary but
extremely accurate volcanic hazards assessment and a hazards zonation map,
which indicated that Clark Air Base and many tens of thousands of people living
around Mt. Pinatubo were directly at risk from an eruption, which looked like
it was about to begin. They communicated that information to U.S. military
officials, the Philippine government, and Philippine mayors of nearby towns.
Damage from lahars,
or volcanic mudflows, at Pinatubo.
In the end, Philippine officials evacuated about a million people from around
the volcano. About 70,000 of those people lived in villages that were totally
destroyed a few days after they left. So literally tens of thousands of lives
were saved, not to mention hundreds of millions of dollars worth of military
equipment, which was moved out of harm's way.
NOVA: When an eruption occurs, do you custom design a team and the equipment
Miller: Absolutely. When unrest begins at a volcano, we always wait for an
official invitation, which usually comes through the State Department or the
U.S. Agency for International Development. We think about the volcano and what
kind of eruptions have occurred there in the past. Then we select a team of
scientists with the kind of expertise that is requested and required, and we
take the kinds of equipment with us that will help out.
Usually we train local scientists to operate and maintain the equipment, which
we invariably give to the host country. It's a nice feeling to help out another
country with something that has the chance of saving lives, and then to offer
them the equipment, no strings attached. We'll say, "We're going to head home
in a couple of weeks, and we're going to leave this stuff here. We'll help you
with spare parts and come down when you need help." They'll often look at us as
if to say, "Well, what do you want from us?" And we can honestly reply,
"Nothing. This is your equipment now, and we hope that it serves you
Installing volcano monitoring equipment at Mt.
NOVA: You just returned from a crisis in Ecuador. What was that like?
Miller: There's an explosive volcano by the name of Guagua Pichincha that lies
about six miles west of Quito, the Ecuadoran capital. Now, Quito has a
population of 1.8 million, and this 15,800-foot volcano has had several periods
of restlessness involving steam explosions and earthquakes. The most recent one
began with a series of steam explosions on August 7th. More than 50 explosions
have occurred since, and there has also been seismicity.
The local scientific team, which has been monitoring volcanos in Ecuador for
about two decades, requested assistance from VDAP. About a month ago we sent a
team of four scientists to Ecuador to provide assistance. Our purpose is to
maintain a low profile, to provide assistance to the local scientific team, and
to help them to understand what's happening so that they can communicate that
information to public officials and civil defense organizations. After we
arrived, we spent time in the field with our colleagues, installing new
equipment and getting the data telemetered back to their observatory.
The restlessness is continuing as we speak. There are daily explosions at the
summit and various types of seismic activity. It's too early to tell whether or
not it will erupt.
NOVA: Would you go back down if they called you back?
Miller: Yes, absolutely. We have a volcanic seismologist from the Alaskan
Volcano Observatory in Anchorage down there now, and he'll be there for the
next several weeks. And we have five additional USGS scientists who are ready
to go at a moment's notice if things escalate. I'm not part of this third wave,
because I'm still recovering from my last trip down there. But I'll be prepared
to go at any time, if something looks like it's about to happen.
VDAP team member Andy Lockhart in action at Mt. Pinatubo, June 1991.
NOVA: What equipment do you bring along?
Miller: We have three complete volcano observatories sitting on the shelf ready
to go right now—two for international use and one for domestic use. They
include three primary tools with which to forecast volcanic eruptions. First, a
telemetered volcanic seismic monitoring network to detect the earthquakes that
often precede eruptions. Second, tiltmeters and electronic distance measuring
networks to monitor bulging or deformation that results from magma pushing up
against the solid rock of the volcano. Finally, devices to measure sulfur
dioxide and carbon dioxide. These two diagnostic gases associated with magma
are fairly easy to detect. When the flux of these gases at the surface
increases with time, we become concerned about magma rising close to the
surface and about the increased likelihood of an eruption. (For more details on
techniques and equipment, see Can We Predict Eruptions?)
NOVA: How much equipment do you bring?
Miller: Lots. In September 1994, for example, we received an urgent request
from the Rabaul Volcano Observatory in Papua New Guinea (see Planning for
Disaster). An eruption was underway, and it had already destroyed most of
their monitoring network, including their tiltmeters and seismometers. Within a
week, we had sent a three-person team with 38 trunks of equipment.
Loading VDAP equipment onto a C-130 in Port Moresby, Papua New Guinea,
The equipment is modular, and so each of these trunks weighed less than 70
pounds, which is the maximum amount that you can ship as excess baggage. But
each had a solar panel, batteries, and either a tiltmeter or a seismometer as
well as all of the cabling and radios. All 38 trunks were flown on commercial
airliners to Port Moresby, Papua New Guinea, where they were put on a military
C-130 and flown into a little airstrip near Rabaul. From there they were
carried by truck to the Rabaul Volcano Observatory, then flown out by
helicopter in modules to the field sites and installed.
NOVA: The VDAP team was right on the volcano during the eruption?
Miller: Yes. We use great caution once an eruption appears to be imminent or,
worse yet, has begun. But you need to get the seismic instruments within a few
miles of the volcano, and tiltmeters need to be installed on the volcano's
flanks. Sometimes that's closer than you want to be. At Pinatubo, when it
became clear that a large eruption was imminent, the team finally decided not
to go back to the mountain to fix or replace damaged equipment. It was simply
too dangerous to go close, even with a helicopter.
Phreatic or explosive steam venting high on Mt. Pinatubo after the June 1991 eruption.
NOVA: How soon after the team left did it erupt?
Miller: Four days. Actually, the big eruption occurred then. There were
dangerous eruptions occurring everyday, even when that decision was made. So we
try to do things in as safe a way as possible. But it's always difficult to
anticipate what a volcano will do. Each is different, each has a unique
NOVA: Eruption prediction is an inexact science. How soon might it approach an
Miller: It's very frustrating that, even with equipment installed and the most
experienced team members that we can assemble, it's extremely difficult to
accurately forecast exactly what the volcano is going to do, when it's going to
do it, and how big an eruption there will be. Part of the frustration is that
scientists don't make decisions about land use, or how to respond to the
unrest, or whether or not to evacuate. That's the reponsibility of civil
defense and elected officials. But these are life-and-death decisions, and they
have huge political and economic consequences.
If there's a failed eruption, or a so-called "false alarm," everybody's angry,
money is lost, and both scientists and public officials lose credibility. By
the same token, if scientists don't understand what's about to happen, or
public officials don't believe what the scientists think is about to happen,
and people are not evacuated, and an eruption occurs and people are killed,
then everyone is even angrier. We do the very best we can to provide good,
accurate information to public officials. But we're never in a position where
we can say we're confident that an eruption will occur within "x" number of
days and be of a certain size and destroy a certain area.
VDAP and local
scientists install a tiltmeter at Soufriere Hills volcano, Montserrat, August
When will forecasting get better? It's improving year by year. Every time we
work on a volcano crisis, we learn more about how to interpret the subtle and
sometimes very sophisticated signals that volcanoes give as magma moves around.
There are a whole suite of different kinds of earthquakes, for instance:
volcano tectonic earthquakes, long-period earthquakes, volcanic tremor. It's a
very, very complicated business. However, compared to earthquake predictions,
we're extremely lucky; no one has any ability to forecast earthquakes.
NOVA: I've read that you don't think of yourselves as "cowboys," despite the risks
Miller: We don't consider it to be very dangerous. We try to be sensible; we
have families, and we want to do this over the long term. Since we work for the
U.S. government, our policy has always been that we will never ask any of our
scientists to do anything that they're uncomfortable with. We discuss as a team
what our objectives are, what kind of equipment we'd like to get installed, and
what kind of observations we'd like to make, and then scientists decide whether
they're willing to do it or not and on what terms.
VDAP staffer Andy Lockhart
sets up a seismometer within sight of Mt. St. Helens, September 1992.
NOVA: Ever had any close calls yourself?
Miller: I'm a pretty cautious person. I worked at Mt. St. Helens for years
before the 1980 eruption, for seven or eight months during that year, and off
and on ever since. But when the volcano was erupting, and when it was restless
between eruptions, I was pretty darn careful. I spent very, very little time up
in the crater, because it was quite a dangerous place because of rock falls off
the crater rim and explosions on the dome. When I worked all over the blast
zone in the summer of 1980, I and my colleagues were always pretty close to the
helicopter, ready to start it up and leave at a moment's notice.
Photos: (1-4, 6) USGS; (5) Andy Lockhart; (7) C. Dan Miller; (8) Steve
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