ANNIVERSARY - Mtount St. Helens

"From Mt. St. Helens' volcanic ashes, Mother Nature rebuilds" PBS NewsHour 5/18/2016

Excerpt

SUMMARY:  Wednesday marks the 36th anniversary of the deadliest volcanic event in U.S. history: the eruption of Mount St. Helens, which killed every living thing in a 230 mile radius.  But the slopes around the volcano are now beginning to repopulate with plant and animal life, giving biologists a unique opportunity to watch an ecosystem develop in real time.  Science correspondent Miles O'Brien reports.

MILES O'BRIEN (NewsHour):  Thirty-six years after its spectacular, deadly eruption, Mount St. Helens still rumbles and bears scars from that earth-shattering day.

But hike down the slopes, away from that jagged crater just a little, and you will see Mother Nature hard at work.  And there's a good chance you will bump into a team of scientists led by John Bishop.  He is an evolutionary biologist at Washington State University-Vancouver.

JOHN BISHOP, Washington State University-Vancouver:  The goal of our research is to understand how plant and animal communities reform after a catastrophic disturbance.

MILES O'BRIEN:  Bishop is one of a select group of researchers studying this rebound from a volcanic eruption.  Back in 1980, Mount St. Helens had given scientists all kinds of clues that a big disturbance was brewing.

Two months before it blew, the volcano was venting huge amounts of steam and there was a series of earthquakes.  Even with all those ominous signs, the eruption was larger than anyone predicted.  It happened at 8:32 on the morning of May 18, 1980.  An earthquake caused the north face of the mountain to collapse.

JOHN BISHOP:  After that, it uncorked an explosion that was directed horizontally, and leveled the forest to 13 miles out from the volcano.

MILES O'BRIEN:  The eruption column of volcanic ash and gas rose 80,000 feet, while a tsunami of 1,800-degree gas and rock raced down the valley at 450 miles an hour, a so-called pyroclastic flow.

JOHN BISHOP:  Anything biological that was remaining after the landslide would've been completely vaporized.  It was just a barren landscape, gray and pumice-colored.

MILES O'BRIEN:  It killed every living thing in a 230-square-mile area.  What was left was akin to a moonscape; 57 people died.  Some remains were never recovered.

Bishop and his team have had a front-row seat as nature got busy bringing this place back to life.  They wanted to know where it begins and how it takes root.  Here, it started with these purple flowers.  Alpine lupine were the first plants to return.  For many years, they were pretty much the only game in town.  But as they went through their life cycles over several seasons, they created soil from the volcanic ash.

And that made it possible for woody plants, like the Sitka willow, to find a home.  They are how a forest gets started, but it hasn't been easy for them.

MEXICO - Volcano Rattles Nerves

"Volcano Puts Mexico on Alert" by JEAN GUERRERO, Wall Street Journal 4/20/2012

The towering Popocatépetl volcano outside Mexico City rumbled loudly and spewed plumes of ash, water vapor and hot rocks high into the sky on Friday, scaring nearby residents and putting Mexican officials on alert.

Mexican President Felipe Calderón visited nearby communities and flew close to the crater Friday morning, later calling on residents via his Twitter account to prepare in case of a needed evacuation by keeping at hand a battery-powered radio, flashlight, medicine and important documents.

"It is important to keep calm," Mr. Calderón wrote. "We are closely watching the activity of Popocatépetl."

Authorities mapped out evacuation routes, and prepared shelters in case the volcano's activity increases.

Experts say a massive eruption of the 17,886-foot (5,450-meter) volcano is unlikely, but a buildup of a magma chamber under its slopes may release clouds of thick ash that could blanket Mexico City and cause havoc at its international airport.

"Popo," as the volcano is affectionately known in Mexico, came back to life in 1994 after decades of relative quiet and regularly emits puffs of ash and vapor. In fact, the volcano's name in Mexico's indigenous Nahuatl language means "smoking mountain."

In the past week, the volcano's activity suddenly increased, forcing authorities to raise the alert level and place a seven-mile security radius around the mountain, which sits 35 miles outside of the capital.

Overnight on Friday, the volcano emitted a deep roar that could be heard for miles and spooked residents. Experts say the volcano's emissions have been particularly frightening to nearby residents at night because they give the false impression of being lava.

"The material has a certain temperature that makes it look incandescent at night, and that is why you see the red," said Juan Carlos Mora Chaparro, a volcanologist at the Geophysics Institute of the National Autonomous University of Mexico. However, he said that unlike lava, the materials being emitted are cool by the time they reach the ground.

Mr. Mora said it is impossible to know how far the effect of a potential volcanic eruption would reach at this point, but that it could destroy areas many kilometers away.