Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock () or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Volcano Hazard Program images.
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.
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.
Map of Mount St. Helens Crater Glacier created from LiDAR data acquired September 2009.
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.
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.
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: 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.
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.
Julia Griswold is a geologist with the USGS-USAID Volcano Disaster Assistance Program.
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.
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.
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.
Resistivity values for wet (average 7.8 Wt.% moisture content) compacted (lighter shades) and uncompacted (darker shades) fresh ash samples.
Resistivity values for wet (average 7.8 Wt.% moisture content) compacted (lighter shades) and uncompacted (darker shades) fresh ash samples.
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.
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.
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.
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.
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.
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 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.
This fissure eruption on Kīlauea's East Rift Zone in March 2011 reminds us of how exciting it can be to live on or near active volcanoes, but also why we need to be aware of the hazards they pose.
This fissure eruption on Kīlauea's East Rift Zone in March 2011 reminds us of how exciting it can be to live on or near active volcanoes, but also why we need to be aware of the hazards they pose.
This image was captured on Tuesday, December 10 by Landsat 8, a new NASA Earth-observing satellite that was launched in February of this year and entered service in May. The image shows the Pu‘u ‘Ō‘ō lava flow field on Kīlauea's east rift zone. Although this is a false-color image, the color map has been chosen to mimic what the human eye would expect to see.
This image was captured on Tuesday, December 10 by Landsat 8, a new NASA Earth-observing satellite that was launched in February of this year and entered service in May. The image shows the Pu‘u ‘Ō‘ō lava flow field on Kīlauea's east rift zone. Although this is a false-color image, the color map has been chosen to mimic what the human eye would expect to see.
Mount St. Helens and North Fork Toutle River Channel.
Mount St. Helens and North Fork Toutle River Channel.
Pele's hair (thin strands of volcanic glass drawn out from molten lava) is abundant around Halema`uma`u Crater (Kīlauea, Hawaii). It originates from the active, spattering lava lake and in some areas, makes a nearly continuous carpet, highlighted here in the afternoon sun.
Pele's hair (thin strands of volcanic glass drawn out from molten lava) is abundant around Halema`uma`u Crater (Kīlauea, Hawaii). It originates from the active, spattering lava lake and in some areas, makes a nearly continuous carpet, highlighted here in the afternoon sun.
A close-up of Pele's hair at Halema‘uma‘u.