Unified Interior Regions


The Pacific Region has nine USGS Science Centers in California, Nevada, and Hawaii. The Regional Office, headquartered in Sacramento, provides Center oversight and support, facilitates internal and external collaborations, and works to further USGS strategic science directions.

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February 25, 2011

Boom from Vent in Halema‘uma‘u!

Booming sounds from the vent in Halema‘uma‘u have been audible around the summit area of Kīlauea for the past several days. Some of these sounds are caused by rocks striking the surface of the lava lake, but most are actually the sound of the vent walls cracking due to heating and expansion of rock. This video, from February 25, illustrates what this sounds like.

February 25, 2011

Lava Lake Decreases from Vent Collapse

The level of the lava lake sometimes changes abruptly. These cycles of rise and fall, which amount to a vertical change of around 15 m (about 50 ft), are occasionally triggered by rockfalls. Here, a small collapse from the vent wall triggers degassing and a drop in the lava level.

February 25, 2011

Lava Lake Popping

As the spattering shown in the previous video intensifies, the walls of the vent heat even more, causing the cracking of the rocks through thermal expansion to speed up, creating the cacophony of popping noises apparent in this video.

February 23, 2011

Time-Lapse of Lava Eruption at Pu`u `Ō`ō Crater

Time-lapse movie showing lava erupting from vents on the floor of Pu‘u ‘Ō‘ō crater. Each frame is a composite of eight images comprising a panorama of the crater that is captured every five minutes. During daylight hours, the camera switches to an IR mode so that eruptive activity is easier to monitor. At night, the camera switches back to normal mode.

February 15, 2011

Small Explosive Event at Kīlauea's Summit

Another series of collapses occurred within Kīlauea's summit vent on the floor of Halema‘uma‘u before sunrise on February 15. This movie shows the first of the rockfalls and the resulting small explosive event.

Kīlauea's Summit Vent Churns and Pops as Rocks Fall Into the Lava L...
February 14, 2011

Lava lake activity from inside Halema`uma`u Crater

Sounds of lava lake activity within Kilauea Volcano's summit vent inside Halema`uma`u Crater on the afternoon of February 14, 2011. The continuous "crashing wave" noise is the sound of churning lava as gases are released from the lake surface, which is in nearly constant motion. The discontinuous sharp "pops" occur when rocks falling from the vent wall hit the lava lake

February 6, 2011

Lava Flows in Pu`u `Ō`ō Crater

Movie of lava flows in Pu‘u ‘Ō‘ō crater from February 6-8. Lava has been erupting sporadically from three vents within Pu‘u ‘Ō‘ō crater-a cone on the west side of the crater floor (foreground to left), a cone on the northeast side (center frame), and from an opening on the east crater wall (background).

January 21, 2011

Collapse and Plume (Jan 21, 2011)

Movie of the January 21 collapse and dusty plume captured by a Webcam located in the observation tower at the Hawaiian Volcano Observatory.

January 17, 2011

Collapse and Eruption (Jan 17)

Movie of the January 17 collapse and explosive eruption captured by a Webcam located in the observation tower at the Hawaiian Volcano Observatory.

January 17, 2011

Explosive Eruption (Jan 17, 2011)

Movie of the January 17 collapse and explosive eruption captured by a Webcam located on the rim of Halema‘uma‘u directly above the erupting vent.

Two color photographs, one showing a clear-day rock-wall face and one showing the rock-wall face obscured by volcanic gases.
December 31, 2010

Side-by-side comparison of the northwest wall of Kīlauea Caldera

Side-by-side comparison of the northwest wall of Kīlauea Caldera on a clear day (left) and a day with thick vog (right). HVO observation tower and building can be seen near the center in each photo

Image: Monitoring Gas Emissions from Kilauea Volcano
November 10, 2010

Monitoring Gas Emissions from Kilauea Volcano

Sulfur dioxide gas emissions from the crater of Pu‘u ‘Ō ‘ō on Kīlauea’s east rift zone and the vent within Halema‘uma‘u Crater at Kīlauea’s summit create volcanic pollution that affects the air quality of downwind communities.  Here, a USGS Hawaiian Volcano Observatory gas geochemist measures Pu‘u ‘Ō‘ō gas emissions using an instrument that detects gas compositions on the

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photo of lava
May 9, 2003

Tiny hornitos at Son of Cookie Monster

Map with lava inundation zones identified for Mauna Loa
May 8, 2003

The primary goal of the U.S. Geological Survey's Hawaiʻian Volcano Observatory is to provide scientific information that can be used to reduce risks due to volcanic activity. To this end, the Observatory assesses volcanic hazards and educates the public and public officials about those hazards.

April 24, 2003

April 26, 2003, marks the 30th anniversary of the magnitude M6.2 Honomu earthquake. This earthquake occurred at 10:26 a. m. and was centered north of Hilo, beneath the town of Honomu. The earthquake caused nearly $6 million in damage, to roads and highways, lifelines and utilities, and over 400 homes and businesses.

photo of lava
April 19, 2003

Kohola breakout 880 m north of coconut grove

Lava spattering from the top of a small cone
April 17, 2003

People like to hear about record-holders-the biggest, fastest, best. That's why we're frequently asked, "What's the world's most active volcano? Is it Kilauea?"

photo of lava
April 15, 2003

Pleasant Sunday morning between rain showers

photo of lava
April 12, 2003

Inflated lava and the ahu: what a difference a day makes