Images

May is Volcano Preparedness Month in Washington State.

Three images of crop damage, ash plume and cleanup for the homepage

Map showing global ash and aviation encounters

Bariloche sand filters

During the cleanup after the 18 August 1992 eruption of Mt Spurr volcano, Alaska. The population of Anchorage used mostly wet methods to clean up the ash, creating a peak water demand which resulted in water shortages and loss of pressure in some parts of the city due to bottlenecks in the distribution system.

Ashfall will cause accelerated wear and tear on sewage pump impellers (metal pitting and thinning).

Sampling gas and taking temperature measurements from a fumarole at the summit of Mount Rainier, Washington.

Streamflow measurement and water sampling at Paradise Creek are part of the regular measurements taken during hydrothermal monitoring campaigns at Mount Rainier, Washington.

The older or original suggested location of this rift is shown with a blue dashed line. Black arrows show one possibility for the westward migration of the Nīnole Hills rift to the location of Mauna Loa's current Southwest Rift Zone (yellow dashed line). The South Kona Slump and ‘Ālika-1 and ‘Ālika-2 landslides are shown off the west coast of the island.

CalVO scientist Tom Sisson studies a lava flow in the Harrat Rahat Volcanic Field in Saudi Arabia for an international collaboration with the Saudi Geological Survey to conduct a seismic and volcanic hazard assessment for the volcanic field.

Map of hazard zones for ground fractures and "small-scale" subsidence for the Island of Hawai‘i. Subsidence and fracturing events are frequent in zone 1, which covers the summit and rift zones of Kīlauea and Mauna Loa volcanoes, but are somewhat less frequent in zone 2, on the south flank of Kīlauea.

Simulated fractures and subsidence above a widening dike (dark area at bottom) were generated in a small-scale model using a box filled with flour, sugar, and corn meal. The simulated dike (tip is dark area bottom center of photograph) consisted of two linoleum sheets taped together.

This part of the south flank of Kīlauea Volcano moved seaward about 6 m (20 ft) and subsided about 3.5 m (11.5 ft) as a result of the magnitude-7.7 earthquake. A tsunami swept ashore at Halapē and reached 14.6 m (48 ft) above the post-earthquake shoreline.

Volume of products, eruption cloud height, and qualitative observations (using terms ranging from "gentle" to "mega-colossal") are used to determine the explosivity value. The scale is open-ended with the largest volcanic eruptions in history (supereruptions) given magnitude 8.

Mount Rainier 2018 Teacher Workshop

Graph shows thickness of ash (and larger-sized particles within 20-40 km) that fell to the ground downwind of Mount St. Helens during the eruption on May 18, 1980. The volcano ejected a minimum of 1.1 km3 of uncompacted tephra, which is equivalent to 0.20-0.25 km3 of magma or solid rock.

Sideromelane and tachylite shards collected 12 km from source at Mount Etna, 2002. The width of view is 1 mm

Table of ash fall severities based on accumulated thickness.

Heavy ashfall (20-30 mm) from Tungurahua, Ecuador, 2006.

Collapsed roofs after severe ashfall from Galunggung Volcano, West Java, Indonesia.

Minor ashfall on hay field, Augustine eruption, Homer area, Alaska, 1986.