When Nevado del Ruiz volcano in Colombia began showing signs of restless activity in December 1984 after more than a century of quiet, a formal volcano-monitoring and risk-reduction program did not exist in the country.
On November 13, 1985 — after seismic monitoring was installed in July and a volcano hazard map was completed in October with international assistance — the volcano erupted. The eruption was hidden in clouds and later in darkness, and fast-moving lahars, volcanic debris flows, raced down rivers draining the volcano.
Tragically, the eruption warnings were not disseminated widely and acted upon swiftly enough and, within hours, the lahars killed at least 25,000 people and injured nearly 5,000.
In the months following this tragedy, the U.S. Agency for International Development’s Office of Foreign Disaster Assistance enlisted the U.S. Geological Survey to help create a program to reduce fatalities and economic losses in countries experiencing a volcanic crisis. The two agencies founded a partnership known as the Volcano Disaster Assistance Program in 1986, headquartered at the USGS Cascades Volcano Observatory in Vancouver, Wash.
Now in its 26th year of operation, VDAP’s strategy of risk reduction includes providing technical expertise during volcanic emergencies, developing and deploying volcano monitoring networks on active or restless volcanoes and providing training and workshops to host-country scientists and emergency management officials. It has proven extremely effective in saving lives, reducing economic costs from eruptions and building strong in-country risk-reduction capability.
Responding to official requests from other countries through the U.S. State Department, VDAP has participated in 25 major volcanic crises, helped install volcano-monitoring systems in more than a dozen countries and trained hundreds of scientists and technicians. VDAP’s work directly saved tens of thousands of lives, notably during eruptions of Mount Pinatubo, Philippines, in 1991; Nevado del Huila, Colombia, in 2007 and 2008; and Merapi Volcano, Indonesia, in 2010.
Following the 1985 tragedy, VDAP has worked with Colombia’s scientists on several volcanic crisis responses and capacity-building projects, including direct involvement in establishing three observatories. One at Manizales is responsible for monitoring and issuing warnings of activity at Ruiz. The observatories are part of the Colombian Geological Service.
Two months ago in early March, Colombian scientists detected a significant increase in earthquake activity at shallow levels beneath Nevado del Ruiz and sulfur dioxide gas emissions. The seismic activity increased in early April, and the volcano’s alert level was raised to the second highest status, signaling that an eruption was likely in days or weeks.
Local and national relief agencies activated contingency plans developed after the 1985 disaster, and people living in river valleys below the volcano were alerted to the potential threat of lahars.
Colombia formally requested additional VDAP assistance through the U.S. State Department. For the past three weeks, a three-person VDAP team has worked with Colombia’s scientists to consult in the interpretation of the earthquake activity and upgrade components of the monitoring network, including a lahar-warning system developed at the Cascades Volcano Observatory.
Scientists interpret the recent activity at Ruiz to be caused by magma rising to a shallow level beneath the volcano. The magma, however, appears to have stalled, thereby preventing an eruption thus far, but allowing for the release of large amounts of sulfur dioxide gas into the atmosphere. Time and continued vigilance by Colombia’s scientists will tell whether the intrusion will start anew, possibly leading to an eruption from the summit crater and lahars, or return to a period of quiet.
The Ruiz tragedy serves as a strong reminder that scientists and emergency management officials must focus on the effective dissemination of warnings and participate in the development of emergency response plans so people know what to do when a volcano erupts. VDAP’s monitoring and training strategy and its focus on communication between everyone involved in a volcanic emergency in the past 25 years has proven itself over and over again.
Kilauea activity update
A lava lake present within the Halemaumau Overlook vent during the past week resulted in nighttime glow visible from the Jaggar Museum overlook. The lake, which is normally about 260 to 380 feet below the floor of Halemaumau Crater and visible by HVO’s webcam, rose and fell slightly during the week in response to a series of deflation-inflation cycles.
On Kilauea’s east rift zone, surface lava flows were active on the pali and coastal plain over the past week. The flow front that was advancing toward the ocean last week stalled early this week, shortly after a new breakout near the base of the pali began May 6. This new breakout has advanced toward the ocean and, as of Thursday, was still more than 0.6 miles from the water.
One earthquake was reported felt beneath Hawaii Island this past week. A magnitude 3.0 earthquake occurred May 6 at 4:40 p.m. and was located four miles southwest of Kilauea summit at a depth of 18 miles.
Visit hvo.wr.usgs.gov for detailed Kilauea and Mauna Loa activity updates, recent volcano photos, recent earthquakes, and more; call 967-8862 for a Kilauea summary; email questions to askHVO@usgs.gov.
Volcano Watch is a weekly article and activity update written by scientists at the U.S. Geological Survey’s Hawaiian Volcano Observatory.
