volcano

In November 2000, rangers at Hawaii Volcanoes National Park made a gruesome discovery. The bodies of a man and a woman, in an advanced state of decomposition, were found near the site where lava from the Kilauea eruption flows into the sea, sending up plumes of scalding white steam. The area, aptly named the Eruption Site, is littered with chunks of tephra, a glassy volcanic rock, which are formed and ejected violently into the air when the 2,000-degree-Celsius lava is quenched by seawater.

El Salvador’s Lake Ilopango, near the capital city of San Salvador, is known for boating, diving and the rugged, scenic beauty of its 100 meter-tall cliffs --- the lip of the caldera that holds the lake. However, 1,500 years ago, it may have been the site of one of the most horrific natural disasters in the world. It may also be the long-sought cause of the extreme climate cooling and crop failures of A.D. 535-536, reported Robert A.

It may seem that there has been an unusual amount of volcanic activity lately, with major eruptions occurring in Iceland, Guatemala and Ecuador. But is it really unusual, and are the eruptions connected?

The short answer to both questions is no.

As we neared the top of the West Face of Mount Shasta, my calf muscles felt like they were pulling apart, stretching to the breaking point. My crampons merely dinted the shimmering snow, leaving dainty bird-like tracks. Roped behind our guides, our group of three climbers switchbacked slowly up the 35-degree-angle slopes. Approaching nearly 4,000 meters in elevation, my lungs grasped for air.

For breathtaking volcanic scenery, few places have the variety found in Lassen Volcanic National Park in the Cascade Range of Northern California. The park boasts five varieties of volcanoes: plug domes, cinder cones, lava cones, shield volcanoes and a stratovolcano called Brokeoff volcano (or Tehama volcano). Bubbling hot springs, boiling mud pots and fumaroles in six geothermal fields in the southern part of the park complete the picture.

Thirty years ago today, sometime not long after 8:30 a.m. Pacific time, Mount St. Helens explosively erupted. The shock wave from the eruption washed over Oregon and Washington, shaking the ground up to 400 kilometers away. Two earthquakes followed, at 8:32 and 8:34 a.m. Shortly thereafter, with a tremendous burst, the upper north flank gave way as gas, steam and ash vented outward and sent out an immense landslide of hot rock, mud, water, ash and debris.

When an Icelandic volcano with a nearly unpronounceable name erupted after 200 years of quiet in March, it was little more than a curiosity. But when it erupted again in April — this time spewing huge clouds of ash as high as 11 kilometers into the stratosphere, quickly choking airways across Europe and costing airlines billions of dollars — it captured the world’s attention. As the ashfall decreased and airlines resumed normal routes this week, the headlines began to fade.

EARTH’s Carolyn Gramling is in Vienna, Austria, at the European Geophysical Union meeting this week. Here are a few more sessions that she has found interesting (for more from the meeting, see her first “Dispatches”).