This date in science: Cataclysmic eruption at Mount St. Helens

On May 18, 1980 – 34 years ago today — a cataclysmic eruption occurred at Mount St. Helens. It was one of the most destructive volcanic events ever recorded in the history of the United States.

Mount St. Helens is a 2549-meter (8363-feet) high stratovolcano that is located in Skamania County, Washington. It is the most active volcano in the Cascade Range, which runs along the northwestern coast of North America. The Cascade Range is part of the Pacific Ring of Fire.

The eruption at Mount St. Helens on May 18, 1980 was preceded by several geological events earlier in the year. Starting on March 16, 1980, a series of small earthquakes struck the region, and on March 27, 1980, a large amount of steam was vented from the volcano. By mid-May, thousands of earthquakes had been recorded and a large bulge had formed along the northern flank. The bulge extended outward to approximately 140 meters (450 feet). All of this geological activity indicated that magma was rising up into the volcano.

On the morning (8:32 a.m. PDT) of May 18, 1980, a 5.1 magnitude earthquake struck and the bulging northern flank of the volcano collapsed along with the summit. The collapse allowed hot pressurized magma in the volcano to erupt and large amounts of material were ejected over the course of the next nine hours. The ash plume from the eruption reached a towering height of 24 kilometers (80,000 feet), and thick ash blanketed the surrounding region.

Photograph of Mount St. Helens taken during the May 18, 1980 eruption. Image Credit: Oman/Combs, National Park Service.

The dense forest that covered the slopes of the volcano was reduced to ash inside an area known as the inner blast zone, which extended about 10 kilometers (6.2 miles) from the summit. Trees farther away from the inner blast zone were also damaged by the searing heat.

Lahars, which are a type of volcanic landslide, formed rapidly from the melting ice, snow and muddy debris released during the collapse of the volcano’s flank and summit. The lahars caused extensive damage to homes, roads and bridges in nearby communities outside of the inner blast zone.

Fifty seven people including volcanologist David A. Johnston and photojournalist Reid Blackburn lost their lives during the May 18, 1980 eruption at Mount St. Helens.

 Mount St. Helens photographed seven years before the 1980 eruption. Image Credit: U.S. Forest Service.

Mount St. Helens photographed two years after the 1980 eruption. Image Credit: Lyn Topinka, U.S. Geological Survey.

Since 1980, Mount St. Helens has continued to experience periodic earthquakes and volcanic eruptions, but not to the same extent of that seen in 1980. The Cascades Volcano Observatory continues to monitor activity at Mount St. Helens, and while it is still active, there are no current signs of a large impending eruption.

Bottom line: On May 18, 1980—34 years ago today—a cataclysmic eruption occurred at Mount St. Helens. It was one of the most destructive volcanic events ever recorded in the history of the United States.

- EarthSky

Indonesia’s Mount Kelud Erupts

A major eruption occurred at Indonesia’s Kelud volcano on February 13, 2014. The eruption sent a large plume of ash drifting west across Java and over the Indian Ocean. According to an advisory issued by the Australian Bureau of Meteorology, ash had reached 13 kilometers (45,000 feet) in altitude, prompting the closure of several airports. Three people were killed, and Indonesian authorities have evacuated more than 75,000 people from their homes.

• References

• European Space Agency (2014, February 14) Kelut Volcano Grounds Air Travel. Accessed February 14, 2014.
• Klemetti, E., via Wired (2014, February 14) Significant Eruption Started at Indonesia’s Kelut. Accessed February 14, 2014.
• Jakarta Globe (2014, February 14) Death Toll Rises as Tens of Thousands Flee Mount Kelud Eruption. Accessed February 14, 2014.
• NPR (2014, February 14) Massive Volcanic Eruption In Indonesia Blankets Region In Ash. Accessed February 14, 2014.
• Smithsonian Global Volcanism Program (2014, February 14) Kelut. Accessed February 14, 2014.

NASA Earth Observatory image by Jesse Allen, using data from the Land Atmosphere Near real-time Capability for EOS (LANCE). Caption by Adam Voiland.

Instrument: 

Aqua - MODIS - NASA

Ongoing Eruption of Sinabung Volcano, Indonesia

Until 2010, Indonesia’s Sinabung volcano was dormant, with no confirmed eruptions in the historical record. A brief burst of activity in August and September 2010 caused the temporary evacuation of about 30,000 nearby residents, but most people quickly returned as the eruption waned.

Three years later, fresh gas and ash plumes marked the arrival of a new series of eruptions. The Advanced Land Imager (ALI) on the Earth Observing-1 (EO-1) satellite collected this natural-color image of an ash plume from Sinabung on February 6, 2014. Frequent collapses from the unstable lava dome near Sinabung’s summit create pyroclastic flows that have swept at least 4.5 kilometers (2.8 miles) down the volcano’s slopes. The flow deposits are visible southeast of Sinabung’s summit and appear light gray.

The eruption has coated much of the surrounding landscape with ash, causing green dark green forests to appear tan. Turn the image comparison tool on to see how much the landscape has changed compared to 2013. The ash has coated nearby villages, as well as the coffee, chili pepper, and other plantations clustered at the foot of the volcano. (The light-colored villages and fields near Sinabung, as well as the dark green forests of Gunung Leuser National Park, are visible in a 2003 Landsat 7 image.)

On February 1, 2014, the volcano killed 15 people when hot debris engulfed the village of Sukameriah.

1. References

2. Bad Astronmy, via Slate. (2014, February 7) Like Volcanoes Aren’t Scary Enough, Now They’re Spawning Twisters. Accessed February 7, 2014.
3. CNN (2014, February 5) Searches halted in Indonesia after Mount Sinabung eruptions kill 15. Accessed February 7, 2014.
4. Eruptions Blog, via Wired (2014, February 1) 14 People Killed in Pyroclastic Flow at Sinabung. Accessed February 7, 2014.
5. Global Volcanism Program (2010) First Holocene eruption; ash explosions during August-September 2010. Accessed February 7, 2014.
6. Roscoe, R. (2014) Sinabung Volcano (Gunung Sinabung). Accessed February 7, 2014.

NASA Earth Observatory images by Jesse Allen, using EO-1 ALI data provided courtesy of the NASA EO-1 team and Landsat data from the U.S. Geological Survey. Caption by Robert Simmon and Adam Voiland.

Instrument: 

EO-1 - ALI - NASA

Death toll climbs to 16 since Mount Sinabung eruption

Mount Sinabung in Indonesia photographed on January 29, 2014. Image Credit: Rendy Cipta Muliawan.

Thousands displaced from their homes. Disaster agencies still mobilizing medical and social services. A thin layer of ash expected to arrive in Malay Peninsula on Wednesday.

As of today (February 5, 2014), the death toll from a February 1 eruption at Mount Sinabung in Indonesia has risen to 16. Authorities recovered another body from the disaster scene, and a person with life-threatening injuries died in a hospital. The large eruption occurred following four months of heightened activity at the 2,460-meter-high (8,069-feet-high) stratovolcano.

A thin layer of ash was expected to arrive in the southwestern portion of the Malay Peninsula this morning. Areas where ash may have fallen today include coastal regions of Negri Sembilan, Malacca as well as Muar, Batu Pahat, Pontian and Kulaijaya in Johor, according to Muhammad Helmi Abdullah, director of region’s National Weather Forecast Center. The ash has the potential to reduce visibility in the region, and, while air travel in Malaysia is not currently being disrupted, the situation is being monitored closely.

The Indonesian National Disaster Mitigation Agency (Badan Nasional Penanggulangan Bencana) is in the process of mobilizing medical and social services to help refugees affected by the eruption. More than 30,000 people have been displaced since the eruptions at Mount Sinabung started in September 2013.
Concern is now growing over the loss of income from crop failures. Many of the refugees are subsistence farmers who make their living growing coffee, cocoa and fruit, according to a report posted on ReliefWeb.
The volcano is located on the island of Sumatra along the tectonically active Pacific Ring of Fire.

 Several volcanoes dot the western coastline of Sumatra in Indonesia. Image Credit: Wikimedia Commons.

Sadly, the February 1 eruption happened just as many villagers were returning home following an evacuation order that was partially lifted, following a decrease in activity from Mount Sinabung.
During the eruption, the volcano spewed hot rocks and ash that reached an estimated height of 2,000 meters (16,000 feet). Nearby areas were covered with a thick blanket of ash, which subsequently made rescue efforts difficult.

Bottom line: As of February 5, 2014, 16 people have died from the large eruption on February 1 at Mount Sinabung in Indonesia. Thousands have been displaced from their homes, and disaster agencies are in the process of mobilizing medical and social services to help refugees affected by the volcanic eruption. A thin layer of ash was expected to arrive in the southwestern portion of the Malay Peninsula this morning (February 5), and, while air travel in Malaysia is not currently being disrupted, the situation is being monitored closely.

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- EarthSky

New Lava Dome Grows on Shiveluch

The summit of an erupting volcano is one of the most dynamic places on Earth. These natural-color Landsat 8 images of Shiveluch were collected one week apart, on January 24 (top) and January 31, 2014 (lower). The two images show ash and pyroclastic flow deposits accumulating on the Russian volcano’s slopes. The pyroclastic flows are generated by collapses on a new lava dome, that is growing on the northwest face of a dome that had recently been the site of most activity. Turn on the image comparison tool to spot the differences.

Lava domes form when thick lava piles up around the erupting vent, cooling into a mound. Such domes expand from the inside as an eruption continues; eventually the outer crust crumbles, spilling debris down the volcano’s slopes.

A tall ridge—created by a massive, Mount St. Helens-like eruption in 1964—prevents debris from the new dome from flowing northward, instead redirecting it to the southwest. In contrast, many earlier flows traveled to the south-southeast.

Stratovolcanoes like Shiveluch and Mount Saint Helens are constructed by the buildup of different types of lava, debris, and ash. The process takes thousands to hundreds of thousands of years. Analysis of the resulting layers allows geologists to decipher a volcano’s history.

The Kamchatka Peninsula contains 43 stratovolcanoes, including Shiveluch. Of these, Shiveluch is one of the largest and most active. It has an elevation of 3,283 meters (10,768 feet).

1. Related Reading

2. Global Volcanism Program (2014, January 28) Shiveluch. Accessed February 4, 2014.
3. Global Volcanism Program The Kamchatka and mainland Asia region. Accessed February 4, 2014.
4. NASA Earth Observatory Natural Hazards: Activity at Shiveluch Volcano.
5. NASA Earth Observatory World of Change: Devastation and Recovery at Mt. St. Helens.
6. NASA Earth Observatory (2007, October 6) Observing Volcanos, Satellite Thinks for Itself.
7. U.S. Geological Survey (2011, January 3) Principal types of volcanoes. Accessed February 4, 2014.

NASA Earth Observatory images by Jesse Allen and Robert Simmon, using Landsat data from the USGS Earth Explorer. Caption by Robert Simmon and Holli Riebeek.

Instrument: 

Landsat 8 - OLI - NASA

Nyamuragira and Nyiragongo Venting Gas above the Congolese rainforest

The sibling African volcanoes, Nyamuragira and Nyiragongo, vented steam and other volcanic gases above the Congolese rainforest on January 29, 2014.

In this false-color image, recent lava flows are black or brown, the volcanic plumes are white or light blue, clouds are white, and vegetation is bright red. The image was collected on January 29, 2014 by the Advanced Spaceborne Thermal Emission and Reflection Radiometer aboard NASA’s Terra satellite.

NASA Earth Observatory image by Jesse Allen and Robert Simmon, using data from the NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team.

Instrument: 

Terra - ASTER - NASA

Evidence of an Underwater Eruption at Kavachi

Kavachi is an undersea volcano on the southern edge of the Solomon Islands in the western Pacific Ocean. It erupted dozens of times in the 20th century, often breaking the water surface, only to be eroded back below the water line within a few months.

On January 29, 2014, the Advanced Land Imager (ALI) on the Earth Observing-1 (EO-1) satellite captured what could be the start of a new cycle of island life and death. Aquamarine water extends eastward from the submerged volcano; the color is likely from dissolved volcanic gases and lava fragments suspended in the water. Directly above the undersea peak, a bright patch is suggestive of vigorously churning water—but there is no sign that the eruption has broken the surface.

NASA Earth Observatory image by Jesse Allen and Robert Simmon, using EO-1 ALI data from the NASA EO-1 team. Caption by Robert Simmon.

Instrument: 

EO-1 - ALI - NASA

Volcano eruption kills at least 16 people in Indonesia as ash is sent spewing several miles into the air

At least 16 people have been killed by a violent volcanic eruption on the island of Sumatra, Indonesia, which sent ash spewing several miles into the air. The dead include a TV journalist, four high school students and their teacher who went to see Mount Sinabung up close after being told it was becoming safer. Only yesterday thousands of villagers were allowed to return to their homes on the slopes of the volcano despite the fact it has been erupting sporadically for four months.


More images and info HERE (WARNING: GRAPHIC CONTENT!)

- Mail Online