A tumulus in the Coso Volcanic Field, California. This lava was probably more viscous than the lava found in the Hawaii tumuli.
Laszlo Kestay, Ph.D.
Laszlo Kestay is a planetary volcanologist at the US Geological Survey's Astrogeology Science Center.
Laszlo Kestay is a planetary volcanologist working for the US Geological Survey's Astrogeology Science Center. His last name was formerly Keszthelyi and this spelling is still used for his publications. He has worked for the USGS since 1991 but was only hired in 2003. He is member of the NASA MRO HiRISE and ESA ExoMars CaSSIS science teams.
Science and Products
Planetary Volcanology
The USGS Astrogeology Science Center conducts research on planetary volcanology. Volcanism is a key part of the chemical and thermal evolution of planetary bodies, and volcanic eruptions are one of the fundamental processes that create and alter the surface of planetary bodies. We often study volcanoes on Earth in order to better understand eruptions across the Solar System, but we also bring...
Terrestrial Analogs for Research and Geologic Exploration Training (TARGET)
The U. S. Geological Survey (USGS) Astrogeology Science Center (ASC) recently established the Terrestrial Analogs for Research and Geologic Exploration Training (TARGET) program. This service-oriented program is built around the recognition that the Earth is a fundamental training ground for human and robotic planetary exploration, and that ASC is in a unique position in northern Arizona with...
Filter Total Items: 22
Coso Volcanic Field Tumulus
A tumulus in the Coso Volcanic Field, California. This lava was probably more viscous than the lava found in the Hawaii tumuli.
A'a' Channel
Detail of levee on an active channelized aa flow. Note the pahoehoe overflows in the levees and the level of the active flow below the tops of the levees. This lower flow level is not allowed in the commonly used "Bingham" model of lava flows.
Detail of levee on an active channelized aa flow. Note the pahoehoe overflows in the levees and the level of the active flow below the tops of the levees. This lower flow level is not allowed in the commonly used "Bingham" model of lava flows.
A'a' Channel
Detail of levee on an active channelized aa flow. Note the pahoehoe overflows in the levees and the level of the active flow below the tops of the levees. This lower flow level is not allowed in the commonly used "Bingham" model of lava flows.
Detail of levee on an active channelized aa flow. Note the pahoehoe overflows in the levees and the level of the active flow below the tops of the levees. This lower flow level is not allowed in the commonly used "Bingham" model of lava flows.
A'a' Channel
An a'a' channel near the Royal Gardens subdivision on Kilauea Volcano, Hawaii. The flows in the background are from the 1980s. Note that the flow level is below the levees and the pahoehoe overflows emplaced on top of the a'a'.
An a'a' channel near the Royal Gardens subdivision on Kilauea Volcano, Hawaii. The flows in the background are from the 1980s. Note that the flow level is below the levees and the pahoehoe overflows emplaced on top of the a'a'.
Section of Burst Tumulus
A section of burst tumulus that has fallen away from the larger structure. Tumuli can burst when the influx of lava is rapid compared to the rate at which the crust is thickening by cooling. In these cases the pressure driving the lava is significantly greater than the weight of the overlying crust.
A section of burst tumulus that has fallen away from the larger structure. Tumuli can burst when the influx of lava is rapid compared to the rate at which the crust is thickening by cooling. In these cases the pressure driving the lava is significantly greater than the weight of the overlying crust.
Pu’u ‘Ō’ō
Pu’u ‘Ō’ō is a cinder and spatter cone in Kilauea’s east rift zone. It began erupting on January 3, 1983; a summary of its eruption can be found here. This image shows the result of the largest of the collapse pits that began to appear around 1993.
Pu’u ‘Ō’ō is a cinder and spatter cone in Kilauea’s east rift zone. It began erupting on January 3, 1983; a summary of its eruption can be found here. This image shows the result of the largest of the collapse pits that began to appear around 1993.
Channelized Dacite Flow
A crystallized dacite flow in northern Chile. Dacite is extrusive and the volcanic equivalent of granodiorite.
A crystallized dacite flow in northern Chile. Dacite is extrusive and the volcanic equivalent of granodiorite.
Channelized Flow on Socompa
Channelized flows on Socompa. Socompa is a large stratovolcano on the border between Chile and Argentina, the youngest of a chain of volcanoes that runs northeast to southwest.
Channelized flows on Socompa. Socompa is a large stratovolcano on the border between Chile and Argentina, the youngest of a chain of volcanoes that runs northeast to southwest.
Burst tumulus
A burst tumulus near Kamokuna, which is a lava delta where Puʻu ʻŌʻō flows enter the Pacific Ocean. Tumuli can burst when the influx of lava is rapid compared to the rate at which the crust is thickening by cooling. In these cases the pressure driving the lava is significantly greater than the weight of the overlying crust.
A burst tumulus near Kamokuna, which is a lava delta where Puʻu ʻŌʻō flows enter the Pacific Ocean. Tumuli can burst when the influx of lava is rapid compared to the rate at which the crust is thickening by cooling. In these cases the pressure driving the lava is significantly greater than the weight of the overlying crust.
West Kamokuna Skylight
Subsequent flows have fed lava into the skylight. A stationary crust is formed on margins of the flowing lava within the tube at this location, probably due to the loss of heat through the skylight.
Subsequent flows have fed lava into the skylight. A stationary crust is formed on margins of the flowing lava within the tube at this location, probably due to the loss of heat through the skylight.
Drippy tumulus
A “drippy” tumulus near Kamokuna, which is a lava delta where Puʻu ʻŌʻō flows enter the Pacific Ocean. These tumuli form when the upwelling lava has a steady pressure and rate of movement, so the upper crust does not break apart. Instead, the lava slowly squeezes out.
A “drippy” tumulus near Kamokuna, which is a lava delta where Puʻu ʻŌʻō flows enter the Pacific Ocean. These tumuli form when the upwelling lava has a steady pressure and rate of movement, so the upper crust does not break apart. Instead, the lava slowly squeezes out.
Cinder Cone in Mount Aso
A cinder cone within the Mount Aso caldera, located on Kyushu Island, Japan. The caldera contains several cinder cones and stratovolcanoes.
A cinder cone within the Mount Aso caldera, located on Kyushu Island, Japan. The caldera contains several cinder cones and stratovolcanoes.
Flat tumulus
Flat-topped tumulus on Mauna Ulu lavas along Chain of Craters Road, Hawaii. Tumuli are just one end-member of a wide range of features formed by inflation of lava flows. A flat-topped tumulus is a half-way between a classic tumulus and a "lava-rise" or inflation plateau.
Flat-topped tumulus on Mauna Ulu lavas along Chain of Craters Road, Hawaii. Tumuli are just one end-member of a wide range of features formed by inflation of lava flows. A flat-topped tumulus is a half-way between a classic tumulus and a "lava-rise" or inflation plateau.
Flat Tumuli
Flat-topped tumulus on Mauna Ulu lavas along Chain of Craters Road, Hawaii. Tumuli are just one end-member of a wide range of features formed by inflation of lava flows. A flat-topped tumulus is a half-way between a classic tumulus and a "lava-rise" or inflation plateau.
Flat-topped tumulus on Mauna Ulu lavas along Chain of Craters Road, Hawaii. Tumuli are just one end-member of a wide range of features formed by inflation of lava flows. A flat-topped tumulus is a half-way between a classic tumulus and a "lava-rise" or inflation plateau.
Detail of pahoehoe lobe
A detail of a pahoehoe lobe at the top of a tumulus. The upper crust that is lifted up during the formation of a tumulus is typically quite vesicular (has lots of bubbled trapped in it). Roza Formation, Columbia River Basalt Group. Southwest of Quincy, WA.
A detail of a pahoehoe lobe at the top of a tumulus. The upper crust that is lifted up during the formation of a tumulus is typically quite vesicular (has lots of bubbled trapped in it). Roza Formation, Columbia River Basalt Group. Southwest of Quincy, WA.
Welded Scoria
Samples of welded scoria. Scoria is another word for the ‘cinders’ that make up volcanic cinder cones. Roza Member, Columbia River Basalt Group. Southeast of Winona, WA.
Samples of welded scoria. Scoria is another word for the ‘cinders’ that make up volcanic cinder cones. Roza Member, Columbia River Basalt Group. Southeast of Winona, WA.
Draped Scoria Cone
Draped scoria cone; partially collapsed. Roza Member, Columbia River Basalt Group. East of Winona, WA.
Draped scoria cone; partially collapsed. Roza Member, Columbia River Basalt Group. East of Winona, WA.
Bifurcating Skylight
A skylight near Pulama Pali, which is the slope where flows from Pu’u O’o make their way toward the sea. Here, the skylight allows one to see where the lava tube is splitting into two branches.
A skylight near Pulama Pali, which is the slope where flows from Pu’u O’o make their way toward the sea. Here, the skylight allows one to see where the lava tube is splitting into two branches.
Pu’u ‘Ō’ō
Pu’u ‘Ō’ō is a cinder and spatter cone in Kilauea’s east rift zone. It began erupting on January 3, 1983; a summary of its eruption can be found here. This image shows the cone just starting to form a collapse pit on its flank.
Pu’u ‘Ō’ō is a cinder and spatter cone in Kilauea’s east rift zone. It began erupting on January 3, 1983; a summary of its eruption can be found here. This image shows the cone just starting to form a collapse pit on its flank.
Pu’u ‘Ō’ō Lava Lake
View of the lava lake found inside the crater in Pu’u ‘Ō’ō cinder cone.
View of the lava lake found inside the crater in Pu’u ‘Ō’ō cinder cone.
Cinder Cones on Mauna Kea
Cinder cones at the summit of Mauna Kea. Mauna Kea is a dormant shield volcano on the north end of Hawaii Island. Astronomical observatories in the foreground.
Cinder cones at the summit of Mauna Kea. Mauna Kea is a dormant shield volcano on the north end of Hawaii Island. Astronomical observatories in the foreground.
Science and Products
Planetary Volcanology
The USGS Astrogeology Science Center conducts research on planetary volcanology. Volcanism is a key part of the chemical and thermal evolution of planetary bodies, and volcanic eruptions are one of the fundamental processes that create and alter the surface of planetary bodies. We often study volcanoes on Earth in order to better understand eruptions across the Solar System, but we also bring...
Terrestrial Analogs for Research and Geologic Exploration Training (TARGET)
The U. S. Geological Survey (USGS) Astrogeology Science Center (ASC) recently established the Terrestrial Analogs for Research and Geologic Exploration Training (TARGET) program. This service-oriented program is built around the recognition that the Earth is a fundamental training ground for human and robotic planetary exploration, and that ASC is in a unique position in northern Arizona with...
Filter Total Items: 22
Coso Volcanic Field Tumulus
A tumulus in the Coso Volcanic Field, California. This lava was probably more viscous than the lava found in the Hawaii tumuli.
A tumulus in the Coso Volcanic Field, California. This lava was probably more viscous than the lava found in the Hawaii tumuli.
A'a' Channel
Detail of levee on an active channelized aa flow. Note the pahoehoe overflows in the levees and the level of the active flow below the tops of the levees. This lower flow level is not allowed in the commonly used "Bingham" model of lava flows.
Detail of levee on an active channelized aa flow. Note the pahoehoe overflows in the levees and the level of the active flow below the tops of the levees. This lower flow level is not allowed in the commonly used "Bingham" model of lava flows.
A'a' Channel
Detail of levee on an active channelized aa flow. Note the pahoehoe overflows in the levees and the level of the active flow below the tops of the levees. This lower flow level is not allowed in the commonly used "Bingham" model of lava flows.
Detail of levee on an active channelized aa flow. Note the pahoehoe overflows in the levees and the level of the active flow below the tops of the levees. This lower flow level is not allowed in the commonly used "Bingham" model of lava flows.
A'a' Channel
An a'a' channel near the Royal Gardens subdivision on Kilauea Volcano, Hawaii. The flows in the background are from the 1980s. Note that the flow level is below the levees and the pahoehoe overflows emplaced on top of the a'a'.
An a'a' channel near the Royal Gardens subdivision on Kilauea Volcano, Hawaii. The flows in the background are from the 1980s. Note that the flow level is below the levees and the pahoehoe overflows emplaced on top of the a'a'.
Section of Burst Tumulus
A section of burst tumulus that has fallen away from the larger structure. Tumuli can burst when the influx of lava is rapid compared to the rate at which the crust is thickening by cooling. In these cases the pressure driving the lava is significantly greater than the weight of the overlying crust.
A section of burst tumulus that has fallen away from the larger structure. Tumuli can burst when the influx of lava is rapid compared to the rate at which the crust is thickening by cooling. In these cases the pressure driving the lava is significantly greater than the weight of the overlying crust.
Pu’u ‘Ō’ō
Pu’u ‘Ō’ō is a cinder and spatter cone in Kilauea’s east rift zone. It began erupting on January 3, 1983; a summary of its eruption can be found here. This image shows the result of the largest of the collapse pits that began to appear around 1993.
Pu’u ‘Ō’ō is a cinder and spatter cone in Kilauea’s east rift zone. It began erupting on January 3, 1983; a summary of its eruption can be found here. This image shows the result of the largest of the collapse pits that began to appear around 1993.
Channelized Dacite Flow
A crystallized dacite flow in northern Chile. Dacite is extrusive and the volcanic equivalent of granodiorite.
A crystallized dacite flow in northern Chile. Dacite is extrusive and the volcanic equivalent of granodiorite.
Channelized Flow on Socompa
Channelized flows on Socompa. Socompa is a large stratovolcano on the border between Chile and Argentina, the youngest of a chain of volcanoes that runs northeast to southwest.
Channelized flows on Socompa. Socompa is a large stratovolcano on the border between Chile and Argentina, the youngest of a chain of volcanoes that runs northeast to southwest.
Burst tumulus
A burst tumulus near Kamokuna, which is a lava delta where Puʻu ʻŌʻō flows enter the Pacific Ocean. Tumuli can burst when the influx of lava is rapid compared to the rate at which the crust is thickening by cooling. In these cases the pressure driving the lava is significantly greater than the weight of the overlying crust.
A burst tumulus near Kamokuna, which is a lava delta where Puʻu ʻŌʻō flows enter the Pacific Ocean. Tumuli can burst when the influx of lava is rapid compared to the rate at which the crust is thickening by cooling. In these cases the pressure driving the lava is significantly greater than the weight of the overlying crust.
West Kamokuna Skylight
Subsequent flows have fed lava into the skylight. A stationary crust is formed on margins of the flowing lava within the tube at this location, probably due to the loss of heat through the skylight.
Subsequent flows have fed lava into the skylight. A stationary crust is formed on margins of the flowing lava within the tube at this location, probably due to the loss of heat through the skylight.
Drippy tumulus
A “drippy” tumulus near Kamokuna, which is a lava delta where Puʻu ʻŌʻō flows enter the Pacific Ocean. These tumuli form when the upwelling lava has a steady pressure and rate of movement, so the upper crust does not break apart. Instead, the lava slowly squeezes out.
A “drippy” tumulus near Kamokuna, which is a lava delta where Puʻu ʻŌʻō flows enter the Pacific Ocean. These tumuli form when the upwelling lava has a steady pressure and rate of movement, so the upper crust does not break apart. Instead, the lava slowly squeezes out.
Cinder Cone in Mount Aso
A cinder cone within the Mount Aso caldera, located on Kyushu Island, Japan. The caldera contains several cinder cones and stratovolcanoes.
A cinder cone within the Mount Aso caldera, located on Kyushu Island, Japan. The caldera contains several cinder cones and stratovolcanoes.
Flat tumulus
Flat-topped tumulus on Mauna Ulu lavas along Chain of Craters Road, Hawaii. Tumuli are just one end-member of a wide range of features formed by inflation of lava flows. A flat-topped tumulus is a half-way between a classic tumulus and a "lava-rise" or inflation plateau.
Flat-topped tumulus on Mauna Ulu lavas along Chain of Craters Road, Hawaii. Tumuli are just one end-member of a wide range of features formed by inflation of lava flows. A flat-topped tumulus is a half-way between a classic tumulus and a "lava-rise" or inflation plateau.
Flat Tumuli
Flat-topped tumulus on Mauna Ulu lavas along Chain of Craters Road, Hawaii. Tumuli are just one end-member of a wide range of features formed by inflation of lava flows. A flat-topped tumulus is a half-way between a classic tumulus and a "lava-rise" or inflation plateau.
Flat-topped tumulus on Mauna Ulu lavas along Chain of Craters Road, Hawaii. Tumuli are just one end-member of a wide range of features formed by inflation of lava flows. A flat-topped tumulus is a half-way between a classic tumulus and a "lava-rise" or inflation plateau.
Detail of pahoehoe lobe
A detail of a pahoehoe lobe at the top of a tumulus. The upper crust that is lifted up during the formation of a tumulus is typically quite vesicular (has lots of bubbled trapped in it). Roza Formation, Columbia River Basalt Group. Southwest of Quincy, WA.
A detail of a pahoehoe lobe at the top of a tumulus. The upper crust that is lifted up during the formation of a tumulus is typically quite vesicular (has lots of bubbled trapped in it). Roza Formation, Columbia River Basalt Group. Southwest of Quincy, WA.
Welded Scoria
Samples of welded scoria. Scoria is another word for the ‘cinders’ that make up volcanic cinder cones. Roza Member, Columbia River Basalt Group. Southeast of Winona, WA.
Samples of welded scoria. Scoria is another word for the ‘cinders’ that make up volcanic cinder cones. Roza Member, Columbia River Basalt Group. Southeast of Winona, WA.
Draped Scoria Cone
Draped scoria cone; partially collapsed. Roza Member, Columbia River Basalt Group. East of Winona, WA.
Draped scoria cone; partially collapsed. Roza Member, Columbia River Basalt Group. East of Winona, WA.
Bifurcating Skylight
A skylight near Pulama Pali, which is the slope where flows from Pu’u O’o make their way toward the sea. Here, the skylight allows one to see where the lava tube is splitting into two branches.
A skylight near Pulama Pali, which is the slope where flows from Pu’u O’o make their way toward the sea. Here, the skylight allows one to see where the lava tube is splitting into two branches.
Pu’u ‘Ō’ō
Pu’u ‘Ō’ō is a cinder and spatter cone in Kilauea’s east rift zone. It began erupting on January 3, 1983; a summary of its eruption can be found here. This image shows the cone just starting to form a collapse pit on its flank.
Pu’u ‘Ō’ō is a cinder and spatter cone in Kilauea’s east rift zone. It began erupting on January 3, 1983; a summary of its eruption can be found here. This image shows the cone just starting to form a collapse pit on its flank.
Pu’u ‘Ō’ō Lava Lake
View of the lava lake found inside the crater in Pu’u ‘Ō’ō cinder cone.
View of the lava lake found inside the crater in Pu’u ‘Ō’ō cinder cone.
Cinder Cones on Mauna Kea
Cinder cones at the summit of Mauna Kea. Mauna Kea is a dormant shield volcano on the north end of Hawaii Island. Astronomical observatories in the foreground.
Cinder cones at the summit of Mauna Kea. Mauna Kea is a dormant shield volcano on the north end of Hawaii Island. Astronomical observatories in the foreground.