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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September 17, 2009

Explosion from the vent in Halema`uma`u

An explosion at 3:13am from the vent in Halema`uma`u ejected hot particles about a hundred yards above the vent rim, and several tens of yards above the Halema`uma`u Overlook. This Quicktime movie (shown at x2 speed) shows the event captured by a low-light camera in the HVO observation tower.

Plants at Kahuku unit in Hawai‘i Volcanoes National Park
September 17, 2009

Plants at Kahuku unit in Hawai‘i Volcanoes National Park

A myriad of plants can be seen from above in this photograph taken at the Kahuku Unit of Hawai‘i Volcanoes National Park. Acquired in 2009, the Kahuku Unit of Hawai‘i Volcanoes National Park has been an area that multiple USGS PIERC researchers study in, including Dr. Steven C. Hess who studies invasive

September 13, 2009

Two degassing holes on the floor of Halema`uma`u

movie shows two degassing holes on the floor of the Halema`uma`u cavity. Lava is just below the rim of the two holes, creating frequent spattering which falls around their rims. Within the larger of the two (on the right), lava can be seen vigorously sloshing. For scale, these openings are about 10 yards wide. The first half of the movie is shown in normal mode, with the

September 9, 2009

Halema`uma`u changing of the typical white to dusty brown plume

movie shows a recent instance of the Halema`uma`u changing from its typical white to a dusty brown. The brown plume events are normally associated with collapses of the cavity walls.

September 3, 2009

Actual speed Quicktime movie showing TEB lava stream through skylight

movie shows a view into the Thanksgiving Eve Breakout (TEB) lava tube, thanks to a skylight (a hole in the roof of the tube). The lava stream, which is about two yards below the skylight, is moving swiftly downhill (the video is shown at actual speed), towards the Waikupanaha ocean entry.

August 10, 2009

Thermal video showing the new gas vent in Halema`uma`u cavity

movie shows the new gas vent which opened yesterday on the floor of the cavity in Halema`uma`u. Following this reawakening, very faint glow was observed last night for the first time since July 4

July 4, 2009

Halema`uma`u showing the lava surface deep within the cavity850

movie shows the lava surface deep within the Halema`uma`u cavity. The lava surface is relatively sluggish, with little movement and only one spattering source.

July 3, 2009

Halema`uma`u showing spattering, sloshing at the ponded lava surface

movie shows a source of minor spattering at the margin of the ponded lava surface within the Halema`uma`u cavity. Weak sloshing of the lava surface can be seen around the spattering source.

June 30, 2009

Lava surface within the cavity of Halema`uma`u

movie shows the lava surface within the cavity at Halema`uma`u. Keeping an eye on the lower left portion of the screen, one can see a large rock impacting the lava surface. This impact appears to trigger degassing and overturning that migrates across a large portion of the lava surface.

Early morning glow from Overlook vent in Halema‘uma‘u Crater, Kīlau...
June 29, 2009

Early morning glow from Overlook vent in Halema‘uma‘u, Kīlauea

Incandescence from the lava lake surface (out of view) reflects an awesome glow on the gas plume rising from the lake surface.

June 25, 2009

Halema`uma`u crusted lava surface and occasional spatter

movie shows activity of the lava surface deep within the Halema`uma`u cavity. The crusted lava surface is moving slowly from northeast to southwest, with occasional bursts of spatter from the margins and cracks. The first half of the movie is shown at actual speed, with the second half shown at x10 speed to convey the sense of movement and illustrate the oscillations of

June 22, 2009

'Nightshot' mode of Halema`uma`u crusted and sluggish

movie shows the lava surface within the Halema`uma`u cavity, again using 'nightshot' mode to see through the fume. The lava surface this evening was considerably more crusted and sluggish than on previous nights, and had risen a minor amount compared to much of last week. The lava migrates from the top of screen towards the bottom, with occasional bubble bursts disrupting

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pāhoehoe flow at base of Pūlama pali, Kīlauea Volcano, Hawai‘i...
May 16, 2002

Pāhoehoe flow at base of Pūlama pali, Kīlauea Volcano, Hawai‘i.

May 16, 2002

On May 19, 1916, at 7:15 a.m., Mauna Loa began to erupt at about the 3,355 m (11,000 ft) elevation on the southwest rift zone. A mushroom-shaped cloud rose 3,000-3,600 m (10,000 to 12,000 feet) above the vent, heralding the eruption.

May 9, 2002

One of the basic objectives for seismographic networks is monitoring and maintaining records of earthquakes and other seismic sources. At the Hawaiian Volcano Observatory (HVO), our monitoring focuses on the active volcanoes. Each year, they give us not only thousands of earthquakes, but also special volcanic seismic sources related to magma transport.

View of Pu`ukapukapu looking eastward along the coast.
May 2, 2002

Pu`ukapukapu sits atop the most imposing cliff along the south coast of Kilauea, towering over the back-country camp site of Halape and dropping 320 m (1,050 feet) precipitously into the sea. Pu`ukapukapu is an impediment to coastal foot travel, an imposing view point, and a mystery.

View across the crater of Pu`u `O`o showing the lava pond
April 25, 2002

Lava has been a frequent visitor at Pu`u `O`o cone these past few weeks. It has flooded the crater floor and erupted from vents around the cone. Previous pond activity was in the autumn of 1999 and, before that, in 1997. What's changed?

April 18, 2002

One evening a couple of weeks ago, the summit of Kilauea began to deform at an impressive rate. Although the ground tilt and associated tremor caused by magma moving beneath the caldera was not humanly perceptible, sensitive instruments let us know that something unusual was up.

April 11, 2002

April is "Tsunami Awareness Month" in Hawai`i. Tsunami is the deadliest natural hazard in Hawai`i. The month of April is chosen to remind people of this hazard because on April 1, 1946, a tsunami, generated in the Aleutians by a magnitude-7.8 earthquake, swept through the islands and killed 159 residents.

volcanic explosion, Kilauea
April 4, 2002

Kīlauea has had many explosive eruptions in the past. Fortunately, we have no evidence that the volcano is building to another one. But it is prudent to examine the past to know what to expect in the future.

photo of lava
March 29, 2002

Spatter structures, and crustal overturning in Episode 55 crater

photo of lava
March 28, 2002

Pu`u `O`o spatter cones, spitting hornito, and rootless shield

March 28, 2002

How big is an eruption? This is a short question with a long answer. Volcanologists, like other people, judge the size of something by comparing it to something else. Volcanic eruptions span such a large range in size, style, and duration that comparisons can be hard, especially between volcanoes with different eruptive styles.

March 21, 2002

From time to time, we get calls from people who are writing about Kilauea, hoping to confirm the idea that Kilauea is the most active volcano on Earth. We have to tell them that, no, it's only one of the most active volcanoes.