Ring of Fire: Ancient Circle of Volcanoes Comes Calling Again

Disaster strikes, with or without warning. Our understanding of the warning signs of impending crises increase as technology and the study of natural disasters grow more sophisticated.

North Sumatra, Indonesia, August 2010

Signs of a possible volcanic eruption motivated more than 10,000 people to evacuate the area of Indonesia's Mount Sinabung last Friday. On Sunday, Aug. 29, the dormant volcano awoke and stretched, sending a cloud of lava and sand nearly one mile into the air. The government recommended any other residents within 6 kilometers of Mount Sinabung evacuate. Masks have been distributed to 7,000 people. Refugees are staying in government buildings, houses of worship, and emergency shelters in nearby towns. Public kitchens have been set up so people can prepare their meals. One volcano-related death has been reported.

Mount Lassen, California, May 1915

Signs of possible significant volcanic activity from dormant Mount Lassen were reported by several residents in the rural community of Manton, and ranchers around the area. Some shaking had been noted for nearly a year, giving reason for keeping watch on the mountain. However, the possibility of an actual live volcano in the continental United States was regarded as almost preposterous.

On May 14, 1915, Lassen, which began as a vent on a large extinct volcano known as Tehama, began to shake in earnest. A large eruption created a new crater. Eight people near Manton reported seeing fire from the volcano, among them the postmistress. She made a written note of it, and called as many people as possible about the activity. Over 100 residents saw the later eruption, and made records, sketches, and some photographs of the activity.

Between May 17-19, reports were made from residents surrounding Mount Lassen that there was a glow being cast on the clouds of the summit crater. Further reports listed it as a steady glow of light, with fire lava on top of the crater. Personnel at the power station in Manton reported seeing incandescent boulders rolling down the west slope.

On May 20, ranchers in Hat Creek Valley were forced to move to higher ground because the streams were flooding from the volcanic flow. The steam blast and lava flow had melted the snow pack, causing additional water in the streams, while their paths were blocked by lava and mud.

On May 22, at 4:45 p.m., there was a huge eruption, with a column of steam, ash, and gas rising over 30,000 feet in the air. It caused the most damage of any previous eruption in the series. It blasted rock and pumice high into the air. Collapse of the column onto Lassen's slopes caused a high-speed avalanche of hot ash, rock fragments, pumice and gas that devastated an area of 3 square miles. Another mudflow followed, rushing down the slopes for 12 miles. Pumice and volcanic ash were deposited more than 25 miles away, and fine ash rained up to 200 miles away from Lassen's northeast peak. The combined mud flow and gas-blast destruction is typical of much of the volcanic activity in the Cascades.

Comparison of Mount Sinabung and Mount Lassen

The events surrounding the eruptions of Sinabung and Lassen are common in many ways. They were noted by increasing seismological activity from volcanoes dormant for centuries. The areas affected were in remote parts of the country, and residents were encouraged to think for themselves about the best course of action. Shelter was provided, but self-care was left to individuals.

Both volcanoes are part of the Ring of Fire, an arc of volcanoes and fault lines encircling the Pacific basin. The hot ash, pumice, and rock fragments sent into the air change the landscape dramatically when they drop back down and harden. Vegetation around both volcanoes was burned and destroyed. Toxins from the lava contaminated the waters and soil of both areas.

I believe the worst part is the uncertainty of when another eruption might occur. It is hard to return and attempt to start life again not knowing how long the volcano might remain stable. The good part is that both the United States and Indonesia are observing the activity, noting similarities, and better preparing for any other dormant volcanoes along the Ring of Fire that might awaken again. International training exercises to rescue those stranded by volcanic activity, and get needed supplies and medical assistance to them as quickly as possible, are an example of better preparation.

Sources:
Forbes.com, Volcano quiet for 400 years erupts in Indonesia
Bloomberg Businessweek, Indonesia Volcano on Sumatra erupts for first time in 400 years
Lassen Volcanic National Park Information
Hotspot: California on the Edge
Eruption of Mount Lassen, California 1915, Dean B. Eppler, Geology Group, Los Alamos National Laboratory, Los Alamos NM & Michael C. Malin, Dpt of Geology, ASU, Tempe AZ