Images

Julia Griswold is a geologist with the USGS-USAID Volcano Disaster Assistance Program.

Seismogram signal examples from volcanic earthquakes: volcano tectonic (VT) Low Frequency (LF)/Deep Long-Period (DLP), hybrid (mix of VT and LF), very low frequency (VLF), and Tremor.

Trout Lake lowland view from the south, downslope from Mount Adams, Washington. The lowland area along the White Salmon River (trees) is underlain by lahar deposits 300 and 6000 years old.

In left foreground, ice-ravaged mafic edifice Little Brother is separated from North Sister by Little Ice Age trough of Collier Glacier. Both North Sister and Little Brother expose numerous oxidized scoria falls, whereas smooth black Middle Sister cone is cloaked by mafic lava flows.

Photo of Crater Lake with oblique bathymetric image of the caldera floor beneath the lake's surface. Oregon

Time history of Yellowstone Caldera uplift (black line) and subsidence patterns along with quarterly catalog earthquake counts (blue bars). Note that large swarms in 1985 and 2010 accompany uplift to subsidence of caldera. The vertical deformation on the right axis was measured at the Sour Creek (SC) dome in the eastern part of the Yellowstone Caldera.

This shaded relief image was produced from LIDAR data. LIDAR is an acronym for Light Detection and Ranging, a modern remote sensing technique used to map topography very accurately—more so than is possible with older techniques. The crater is 1.2 miles (1.9 km) wide east-west. Elsewhere the scale varies owing to the oblique viewing angle.

Wes Hildreth is an expert when it comes to studying the Long Valley Caldera. Here, he is standing on Tertiary basalt lava flows on the north rim of the caldera, view to the southeast with Lake Crowley visible in the center of the caldera, and McGee Mountain above the lake on the skyline.

Top: Map of repeating earthquake areas corresponding to the deformation episodes, below. Bottom: Left 1996-1998 Yellowstone caldera uplift episode. Middle: 1998-2004 subsidence episode. Right: 2004-2010 uplift episode. Bottom: vertical ground deformation from GPS observations at station, WLWY, on the Sour Creek resurgent dome.

Top: Examples of some of the photos taken from helicopter over Mammoth Hot Springs in September 2013. Photos taken by Hank Heasler. Bottom: Hill-shade image calculated from the 2013 DEM over Mammoth Hot Springs and that was derived from a series of overlapping photos using Structure-from-Motion photogrammetry.

The seismic records or waveforms are from two seismic stations, and show the highly repetitive and similar nature of the seismic events.

Map showing one-year probability of accumulation of 1 centimeter (0.4 inch) or more of tephra from eruptions of volcanoes in the Cascade Range.

Tabernacle Hill tuff cone, part of the Black Rock Desert Volcanic Field in Utah, used to house a lava lake in the center of the crater.

CalVO geologist Mae Marcaida examines thin layers of volcanic ash sandwiched between thick beds of sediment deposited by ancestral Mono Lake in eastern California. Each ash layer is evidence of a past explosive eruption of the Mono Craters, which began erupting about 65,000 years ago just south of present-day Mono Lake.

Map of Mount St. Helens Crater Glacier created from LiDAR data acquired September 2009.

Resistivity values for wet (average 7.8 Wt.% moisture content) compacted (lighter shades) and uncompacted (darker shades) fresh ash samples.

The summit lava lake is contained within the Overlook crater, which is about 160 m (520 ft) by 210 m (690 ft) in size, and set within the larger Halema‘uma‘u Crater. The lava lake this week has been about 50 m (160 ft) below the rim of the Overlook crater.

A closer view of the active flows at the forest boundary, and the numerous plumes of smoke resulting from active lava igniting ‘oKAHAKOhi‘a trees and other vegetation.

A closer look at the summit lava lake.

A closer look at the summit lava lake.

The Kahauale‘a 2 flow continues to slowly move through the forest northeast of Pu‘u ‘Ō‘ō. Today, the active flow front was 6.3 km (3.9 miles) northeast of the vent on Pu‘u ‘Ō‘ō. Pu‘u ‘Ō‘ō is just left of the center of the photograph in the distance, partially obscured by the smoke.