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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Kīlauea's 1971 Southwest Rift Zone Eruption: A First in 52 Years...
October 1, 2012

Kīlauea's 1971 Southwest Rift Zone Eruption: A First in 52 Years

As erupting fissures migrated down Kīlauea's southwest rift zone in September 1971 for the first time in 52 years, many spectators hiked into the Ka‘ū Desert for a closer view of the rare event. Hawai‘i Volcanoes National Park rangers patrolled the area on horseback to keep people a safe distance from the lava fountains. Photo courtesy of NPS.

Kīlauea showing familiar pattern—or is it?...
August 2, 2012

Kīlauea showing familiar pattern—or is it?

Hawaiian Volcano Observatory's Recent Earthquakes Web page from Tuesday, July 31, with earthquake shown as colored circles, according to their times of occurrence.

Kīlauea's July 1974 summit eruption: fond memories of dinner by "la...
July 26, 2012

Kīlauea's July 1974 summit eruption

Lava fountains, occasionally surging to heights of 45-55 m (150-180 ft), erupted south and north of Keanakāko‘i Crater (top and middle fissures, respectively) and on the floor of Kīlauea Caldera (foreground fissure) in a spectacular summit eruption on July 19, 1974. A torrent of lava (largely obscured by fume at lower right) gushed to the caldera floor through a pre-

Except for a little friction, Kīlauea's summit and rift zones are w...
July 5, 2012

Kīlauea's summit and rift zones are well connected

A view of the lava lake within the Halema‘uma‘u Overlook vent on an unusually clear day (May 16, 2012) with the Jaggar Museum and the HVO building in the distance.

May 16, 2012

Spattering at Western Margin of Lava Lake at Halema`uma`u

This Quicktime movie shows the impressive spattering at the western margin of the lava lake at Halema‘uma‘u. The continuous spattering is often punctuated by bursts which throw lava onto the ledge (left portion of image), and this accumulating lava is building a spatter rampart. If you focus on the right portion of the image, you can see the slow migration of the lava lake

May 9, 2012

Ongoing spattering at the lava lake in Halema‘uma‘u crater

This Quicktime movie shows spattering that is typical at the margins of the lava lake in Halema‘uma‘u crater. The slow migration of the lava lake surface is normally towards the area of spattering, where the lava sinks back into the magmatic system. Spatter in this clip is being thrown about 5-10 meters (yards) in height. Views like this are fleeting, however, with the

Kīlauea Summit Area Map...
May 7, 2012

Kīlauea Summit Area Map

Map of the summit area of Kīlauea showing the location of the Halema‘uma‘u Overlook vent, and road and trail closures in response to the eruption. Kīlauea's caldera is located within Hawai‘i Volcanoes National Park.

April 14, 2012

High lava stands at Halema‘uma‘u

The lava lake in Halema‘uma‘u has been at a relatively high level over the past week, and several rise-fall cycles (short term increases in lava level immediately followed by spattering and an abrupt drop) pushed the level even higher over the past day. This Quicktime movie is a timelapse sequence taken from the Halema‘uma‘u thermal camera, showing the rise-fall cycles and

April 13, 2012

Continued activity on coastal plain and lava pond in Pu‘u ‘Ō‘ō

A small lava pond, set within a collapse pit, has been active in the eastern portion of Pu‘u ‘Ō‘ō

"DI" tilt events measured at Kīlauea summit March 1-7, 2012. Deflat...
March 29, 2012

"DI" tilt events measured at Kīlauea summit Mar. 1-7, 2012. Deflati...

Tilt measured at the summit of Kīlauea during March 1-7, 2012, shows a series of U- and V-shaped DI events, with deflation indicated by downward tilt and inflation by upward tilt. Images from a thermal camera that overlooks the summit eruptive vent demonstrate how the lava level (noted by white dashed line), depicted by warmer colors, charges across tilt cycles. Tilt is

Royal Gardens in Kīlauea's crosshairs again...
March 22, 2012

Royal Gardens in Kīlauea's crosshairs again

Lava flows creep through the Royal Gardens subdivision on February 24, 2012, slowly burying the few remaining forested kipuka.

Active pāhoehoe on the coastal plain of Kīlauea volcano, Hawai‘i....
March 8, 2012

Active pāhoehoe on the coastal plain of Kīlauea, Hawai‘i.

pāhoehoe flows were active on the coastal plain today, but extended only about 400 m (440 yards) out from the base of the pali. These flows have about 2.8 km (1.7 miles) more to travel to reach the ocean. Farther up the hill, on the steep lower portion of the pali, several active ‘A‘ā cascades are visible.

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photo of lava
October 28, 2003

Early morning spatter in West Gap Pit, and a few aerials

photo of lava
October 24, 2003

Birth of twin "carlitos," and views of Pu`u `O`o crater

October 23, 2003

On November 29, 1975, the latest magnitude-7 earthquake in Hawai`i struck near Kalapana, causing a tsunami that killed two campers at Halape and resulting in $14 million (2003 dollars) in damage. It was the only magnitude-7 earthquake to hit the Big Island during the 20th century.

photo of lava
October 17, 2003

Pu`u `O`o crater and hissing hornitos

October 16, 2003

We're accustomed to seeing news stories about natural disasters around the world where either national or international aid agencies come to the rescue to aid victims. In Hawai'i, the County Civil Defense and Red Cross Agencies are activated in these situations.

October 9, 2003

A recent Hollywood disaster movie depicts a scenario in which the earth's magnetic core has stopped spinning, causing the planet's electromagnetic field to rapidly deteriorate. A series of magnetic anomalies disrupts life and threatens to destroy the earth.

Lava spattering from the vent
October 3, 2003

Lava spattering from the west vent in West Gap Pit of Pu‘u ‘Ō‘ō, Hawai‘i.

October 2, 2003

A recent Hollywood disaster movie depicts a scenario in which the earth's Geologists on the Big Island know that they are among the privileged few in their profession to work around active lava flows. Yet after a few years in Hawai`i, many are overcome by a secret longing for the more varied rocks of the mainland.

September 25, 2003

Good red wine improves with age. So, often, does research. With time, more information is gathered, more thought given, and more sophisticated analysis attempted. The end result may be not only greater accuracy but even elegance.

photo of lava
September 19, 2003

Breakouts continue on the flow field