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Images related to natural hazards.
Lava entering the sea on the western side of flow "61g" is building a platform of new land known as a lava delta, which appears deceptively stable. However, the veneer of lava on the delta surface hides a foundation of loose rubble. As a result, lava deltas are extremely unstable, and they can—and do—collapse without warning.
Lava entering the sea on the western side of flow "61g" is building a platform of new land known as a lava delta, which appears deceptively stable. However, the veneer of lava on the delta surface hides a foundation of loose rubble. As a result, lava deltas are extremely unstable, and they can—and do—collapse without warning.
Backwater flooding across Florida Blvd near the Amite River Bridge in Denham Springs, LA.
Backwater flooding across Florida Blvd near the Amite River Bridge in Denham Springs, LA.
A flooded house near the confluence of the Comite and Amite Rivers near Denham Springs, LA.
A flooded house near the confluence of the Comite and Amite Rivers near Denham Springs, LA.
A flooded neighborhood near the confluence of the Comite and Amite Rivers near Denham Springs, LA.
A flooded neighborhood near the confluence of the Comite and Amite Rivers near Denham Springs, LA.
This map shows recent changes to Kīlauea's East Rift Zone lava flow field at the coast. The area of the active flow field as of August 2 is shown in pink, while widening and advancement of the active flow as mapped on August 12 is shown in red. The base is a Digital Globe image from January 2016.
This map shows recent changes to Kīlauea's East Rift Zone lava flow field at the coast. The area of the active flow field as of August 2 is shown in pink, while widening and advancement of the active flow as mapped on August 12 is shown in red. The base is a Digital Globe image from January 2016.
Main hydrothermal features of the new (2016) 3-D model of the subsurface at Long Valley Caldera. This schematic is based on a survey of the electrical properties of the earth (magnetotellurics) below. Arrows show subsurface water flow, with colors keyed to changing water temperature, from blue (cold) to red (hot). Purple arrows show an extinct hot water pathway.
Main hydrothermal features of the new (2016) 3-D model of the subsurface at Long Valley Caldera. This schematic is based on a survey of the electrical properties of the earth (magnetotellurics) below. Arrows show subsurface water flow, with colors keyed to changing water temperature, from blue (cold) to red (hot). Purple arrows show an extinct hot water pathway.
The explosive event blanketed the rim of Halema‘uma‘u Crater with a layer of tephra (volcanic rock fragments) up to about 20 cm (8 in) thick. The tephra deposit was thickest to the east of the former visitor overlook on the crater rim (shown here), where it formed a continuous layer.
The explosive event blanketed the rim of Halema‘uma‘u Crater with a layer of tephra (volcanic rock fragments) up to about 20 cm (8 in) thick. The tephra deposit was thickest to the east of the former visitor overlook on the crater rim (shown here), where it formed a continuous layer.
In areas not completely blanketed by tephra from the explosive event, impact marks were obvious where large fragments of molten lava (spatter) had landed on the rim of Halema‘uma‘u Crater, then bounced or slid to their current positions.
In areas not completely blanketed by tephra from the explosive event, impact marks were obvious where large fragments of molten lava (spatter) had landed on the rim of Halema‘uma‘u Crater, then bounced or slid to their current positions.
Small plume of ash, steam, and gas rises from the summit crater of Redoubt volcano, Alaska, on March 15, 2009. The plume was observed during an observation and gas-measurement flight by scientists of the Alaska Volcano Observatory, probably the result of a steam explosion in the volcano's active shallow hydrothermal system.
Small plume of ash, steam, and gas rises from the summit crater of Redoubt volcano, Alaska, on March 15, 2009. The plume was observed during an observation and gas-measurement flight by scientists of the Alaska Volcano Observatory, probably the result of a steam explosion in the volcano's active shallow hydrothermal system.
A plume of volcanic gas and ash rises from a vent on the east side of Halema`uma`u Crater, at the summit of Kīlauea caldera. The Hawaiian Volcano Observatory and Jaggar Museum of Volcanology are in the foreground.
A plume of volcanic gas and ash rises from a vent on the east side of Halema`uma`u Crater, at the summit of Kīlauea caldera. The Hawaiian Volcano Observatory and Jaggar Museum of Volcanology are in the foreground.
Plume from the Waikupanaha entry casts a shadow on the sea in the early morning sun.
Plume from the Waikupanaha entry casts a shadow on the sea in the early morning sun.
Mauna Loa March 25, 1984 eruption.
Rocks from the east rim of Kīlauea Volcano's summit vent fell into the lava lake at 10:02 p.m., HST, on Saturday, August 6, triggering an explosive event that hurled fragments of molten and solid rock onto the rim of Halema‘uma‘u Crater.
Rocks from the east rim of Kīlauea Volcano's summit vent fell into the lava lake at 10:02 p.m., HST, on Saturday, August 6, triggering an explosive event that hurled fragments of molten and solid rock onto the rim of Halema‘uma‘u Crater.
Tephra blasted from the summit vent on Saturday night included lithic (solid rock) fragments from the vent wall as well as spatter (molten lava fragments) ejected from the lava lake. The light-colored lithic in the center of this photo is about 20 cm (8 in) long—the GPS unit is shown for scale.
Tephra blasted from the summit vent on Saturday night included lithic (solid rock) fragments from the vent wall as well as spatter (molten lava fragments) ejected from the lava lake. The light-colored lithic in the center of this photo is about 20 cm (8 in) long—the GPS unit is shown for scale.
Volcano monitoring equipment installed on the rim of Halema‘uma‘u Crater was a casualty of Saturday night's explosive event. This pile of charred wires and metal components, surrounded by melted plastic, is all that remains of the power supply for one of HVO's gravity instruments located about 24 m (80 ft) from the crater rim.
Volcano monitoring equipment installed on the rim of Halema‘uma‘u Crater was a casualty of Saturday night's explosive event. This pile of charred wires and metal components, surrounded by melted plastic, is all that remains of the power supply for one of HVO's gravity instruments located about 24 m (80 ft) from the crater rim.
Photos, taken by HVO's webcam on November 17th illustrate the new behavior of the summit eruption plume, which this week began oscillating between strong and robust (left), and weak and wispy (right).
Photos, taken by HVO's webcam on November 17th illustrate the new behavior of the summit eruption plume, which this week began oscillating between strong and robust (left), and weak and wispy (right).
Photo comparison of the emergency access road from July 25, the day the lava first crossed (left), and today August 5 (right). The flow is now approximately 200 m (650 ft) wide on the road and has inflated to a few meters tall (HVO geologist for scale).
Photo comparison of the emergency access road from July 25, the day the lava first crossed (left), and today August 5 (right). The flow is now approximately 200 m (650 ft) wide on the road and has inflated to a few meters tall (HVO geologist for scale).
The Kamokuna ocean lava flow entry continues, and is approximately 250 m (820 ft) wide at the point of entry. The 61g flow pāhoehoe activity on the distal half of the coastal plain continues to widen the flow field.
The Kamokuna ocean lava flow entry continues, and is approximately 250 m (820 ft) wide at the point of entry. The 61g flow pāhoehoe activity on the distal half of the coastal plain continues to widen the flow field.
During the 2016 International Training Program on the Island of Hawai‘i, a USGS Hawaiian Volcano Observatory scientist (center, white shirt) demonstrated how to use Global Positioning System (GPS) equipment to measure precise locations of points on Earth's surface.
During the 2016 International Training Program on the Island of Hawai‘i, a USGS Hawaiian Volcano Observatory scientist (center, white shirt) demonstrated how to use Global Positioning System (GPS) equipment to measure precise locations of points on Earth's surface.
USGS and collaborators from Marine Biological Laboratory and Waquoit Bay National Estuarine Research Reserve building research infrastructure at a salt marsh field site (Cape Cod, MA).
USGS and collaborators from Marine Biological Laboratory and Waquoit Bay National Estuarine Research Reserve building research infrastructure at a salt marsh field site (Cape Cod, MA).
This map shows recent changes to Kīlauea's East Rift Zone lava flow field. The area of the active flow field as of July 26 is shown in pink, while widening and advancement of the active flow as mapped on August 2 is shown in red. Lava reached the ocean on the morning of July 26. Older Pu‘u ‘Ō‘ō lava flows (1983-2016) are shown in gray.
This map shows recent changes to Kīlauea's East Rift Zone lava flow field. The area of the active flow field as of July 26 is shown in pink, while widening and advancement of the active flow as mapped on August 2 is shown in red. Lava reached the ocean on the morning of July 26. Older Pu‘u ‘Ō‘ō lava flows (1983-2016) are shown in gray.