A Volcano Story (Told Three Times)
Rokatenda eruptions August 10, 2013. Photo courtesy of NBCnews.
I. This story starts over the weekend:
On Saturday, August 10, a small Indonesian volcano, masquerading as an island, started erupting violently.
stratovolcano – a steep, conical volcano (the picture-ready one) built up by layers of volcanic material (ash, lava, etc.).
The island goes by many names: Palau, Belau, or Pelew, or, more formally, the Republic of Palau. Roughly the size of the Californian city of San Jose, the island is home to around 20,000 people and one stratovolcano called Mount Rokatenda, or Paluweh.
lava dome – a mound of dense, sticky lava that collects over a vent, or lava source; often found atop or on the side of stratovolcanoes.
Decorating the volcano’s top are many craters and volcanic features, including a lava dome. This weekend, the dome collapsed, meaning the pressure built up too high to support it’s own weight and BOOM.
And then two things happened. First, a hot billowing dark cloud of ash blasted up into the air, towering approximately 2,000 feet. Some of that ash and fine rock rained back down on the island, forming a ~4-8-inch scratchy blanket on the ground.
Below is a movie of part of the eruption and the associated ash cloud, which climbs into the sky like a slithering monster.
pyroclastic flow – a fast-moving cloud of hot ash; such flows can race up to 80 miles per hour and generally get up to between 300 and 700 degrees Fahrenheit (so more than twice as hot as most ovens go).
Second, and more dangerously, multiple pyroclastic flows surged down the side of the mountain, down to the water, devouring everything in their path like a ravenous fiery bullet train, engulfed in smoke, speeding downwards. If you are unfortunate enough to find yourself in the path of such a hellish animal, think you final thoughts. Surviving is not really an option.
Unfortunately, at least six people found themselves in the path of Saturday’s pyroclastic flows. They were on a beach that had been closed months prior due to volcano evacuation warnings. Still, they were there. And within minutes of the eruption, they weren’t. Four bodies are confirmed dead; two are still missing. A few of the victims were children.
Map of likely flow paths; courtesy of earthquakereport.com
Currently, thousands are in shelter on neighboring islands. It is unclear how many homes, farms, animals, roads, etc. were damaged in the event. The volcano is still smoking and belching out rocks.
II. This story starts in October 2012:
On October 8, 2012, Mount Rokatenda shifted from park to drive. In other words, after a decade of relative silence, with a few minor eruptions here or there, the volcano upped its activity. Scientists observed many small earthquakes around the island and the volcano was growing bigger.
Quick to respond, emergency managers and geologists pushed the volcano’s alert level from 1 to 2 (on a scale of 4). Five days later, on October 13, the alert level pushed up one more notch to 3. The area within about two miles of the active area were evacuated; the region classified as at risk and off limits.
In the beginning of November, the ash plumes started. From the island’s horizon, it was clear that smoke stacks extended out of the volcanic crater, up, up and away into the sky. By the end of November, geologists had observed the makings of a large lava dome, just shy of 500 feet in height (or around 197 raptors tall), making it the highest point on the island.
After more of the same of the volcano coughing up ash and flaunting a growing dome for months, like a pregnant mom wearing short shirts to reveal her burgeoning baby bump, the volcano’s eruption was finally born on February 2-3. There was an explosion that spurred a monstrous ash cloud, beastly pyroclastic flows, and rockslides. The islanders, from eight different villages, hit the boats. There do not appear to be any fatalities.
A Nasa satellite image shows rokatenda smoking casually in March 2013.
After that brief stunt of Hollywood action, the volcano simmered down slightly, smoking casually. Until this past weekend in August, that is. Then in a few minutes of spectacular fury, the lava dome collapsed, pyroclastic flows radiated out, and six unfortunate stragglers, who had not paid heed to the evacuations that had been in place since the previous fall, lost their lives.
The volcano is showing no signs of stopping.
III. This story starts eighty-five years ago, to the month:
It was August 4, 1928, and the small Indonesian island of Palau had only a small population. The details are a bit sketchy, but the general idea is clear: There was a huge eruption, which triggered a landslide, which triggered a tsunami (talk about a triple threat!). There was chaos, and death, and destruction. Some reports say 98 people died, others say well over a 100.
On the Volcanic Explosivity Index (VEI), a nifty scale for measuring the intensity of a volcanic eruption, where 1 is low and 8 is bat-shit-insane, this was a 3 or a “severe” eruption. To be clear, only supervolcanoes get up toVEI 7 or 8, and few volcanoes have ever even gotten up to 3 or 4. For reference, the infamous Krakatoa eruption that engulfed an island and killed approximately 36,000 people was a 6. The 1980 Mount St. Helens eruption was a 5, just barely.
The Indonesian volcano, like Thomas the Train, has since kept chugging with more eruptions in 1963, 1972, 1973, 1980, 1984, 1985, and now twice in 2013. (Of course, the volcano also had more historical eruptions well before the 1928 one, but records on those are skimpy.)
Most of the time, volcanoes do not just appear out of thin air and erupt wildly with no warning. Volcanoes have long lives, most of which are relatively calm and peaceful, bookended with periods of activity that can drag on for minutes, hours, days, weeks, months, or even years.
To learn more about the many volcanoes on high alert in Indonesia, visit here. Rokatenda is one of four in the region that scientists are keeping a mama bear-close eye on.
The Raptor Lab 
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