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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color photograph of sand bar and boat ramp
August 11, 2018

Pohoiki boat ramp and sand bar

Close view of the Pohoiki boat ramp during this morning's overflight. The southern-most flow margin has not advanced significantly toward the Pohoiki boat ramp, but black sand and larger fragments from the entry areas have washed ashore to create a sand bar and beach at this site. Geologists observed several small 

August 9, 2018

Lava Entering Ocean Near Isaac Hale Beach Park

Lava continues to enter the ocean near the Isaac Hale Beach Park on Kīlauea Volcano's lower East Rift Zone. Although lava output from fissure 8 remains low, the ocean entry was still active during HVO's helicopter overflight on August 9, 2018. Numerous small streams of lava were oozing into the ocean near Ahalanui, creating weak plumes of laze. The southern flow margin

Color photograph of volcanic vent
August 7, 2018

 Aerial view of the fissure 8 cone

Aerial view of the fissure 8 cone and spillway captured by Civil Air Patrol during their overflight on August 7, 2018. View is toward the south.

New outcrops make good geology
August 6, 2018

New outcrops make good geology

This aerial view of the western part of Kīlauea Volcano's caldera was taken on August 6, 2018. The down-dropped block is faulted about 120 m (400 feet) below the caldera floor. Many 19th-century lava flows are exposed in the fault scarps. Halema‘uma‘u (not visible) is to the left of this photo.

August 6, 2018

Overflight of Kīlauea Summit

Between mid-May and early August, 2018, the depth of Halema‘uma‘u more than tripled and its diameter more than doubled as magma from Kīlauea's shallow summit reservoir moved into the lower East Rift Zone. Evidence of subsidence is visible in this video, taken during an early morning helicopter overflight on August 6, 2018. Cracks and down-dropped blocks of the caldera 

August 6, 2018

Lava Fountaining at Fissure 8

During this morning's overflight, HVO geologists observed low levels of lava fountaining within the fissure 8 spatter cone and crusted lava in the spillway and channel downstream. The significance of this change is not yet clear. Eruptions can wax and wane or pause for days to weeks before returning to high levels of lava discharge. New outbreaks in the area of the active 

Hot, molten lava flows slowly into the ocean, and the temperature difference between lava and water is creating steam.
August 5, 2018

Viscous lava hits ocean water

A viscous pāhoehoe flow from Kilauea Volcano, Hawaiʻi , entering the ocean near Isaac Hale Beach Park on the morning of August 5, 2018.

August 3, 2018

Pāhoehoe Breakout

This lava, erupted from fissure 8 on Kīlauea Volcano's lower East Rift Zone, shows classic pāhoehoe behavior. Exposed to the air, the surface of the flow chills to form a thin crust that can be stretched or broken apart, forming pieces of crust that are "subducted" back into the molten interior. The main sound is wind noise, but crackles can also be heard as flakes of

color photograph of volcanic lava channel
August 3, 2018

Lava in the fissure 8 channel spillway

Lava in the fissure 8 channel spillway was fairly low this morning, with the lava in the channel moving at a

Color photograph of caldera
August 3, 2018

Halema‘uma‘u, taken from the northeastern caldera rim

Early morning photo of Halema‘uma‘u, taken from the northeastern caldera rim. Inward slumping of the crater rim and walls continues. Ash deposits from previous explosions and collapse events

Assessing the Functional Equivalency of Hawaiian fishponds
July 29, 2018

Assessing the Functional Equivalency of Hawaiian fishponds

Hawaiian fishponds were important cultural and economic resources for native Hawaiians as they were an important component of a sophisticated, integrated food production system. However, changing demographics and systems of land ownership resulted in a decline in the use and upkeep of Hawaiian fishponds throughout the 19th century. The cultural value of Hawaiian fishponds

fissures were characterized by low eruption rates
July 29, 2018

fissures were characterized by low eruption rates

During the first two weeks of Kīlauea Volcano's 2018 lower East Rift Zone eruption, fissures were characterized by low eruption rates and small flows. This was because the erupted lava originated from pockets of cooler, less fluid magma stored in the rift zone. Later fissures erupted hotter, more fluid magma, resulting in higher eruption rates and large, fast-moving lava

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HVO logs renewed seismic activity at Lō‘ihi...
June 22, 2017

Since the end of February 2017, HVO seismic analysts have noted a slight uptick in the numbers of earthquakes near Lō‘ihi.

Thermal image shows crack across lava delta...
June 22, 2017

Thermal image shows crack across lava delta

Active surface breakouts continue near the 61g vent...
June 21, 2017

Active surface breakouts continue near the 61g vent

No visible breakouts on the coastal plain...
June 16, 2017

No visible breakouts on the coastal plain

HVO's masked geologist heads north to Alaska...
June 15, 2017

Tim Orr accepted a research geology position at the Alaska Volcano Observatory (AVO) in Anchorage, so he's headed north to Alaska. 

Latest upgrade of seismic stations at Kīlauea summit completed...
June 8, 2017

Field engineers at the USGS Hawaiian Volcano Observatory (HVO) recently completed a multi-year effort to upgrade a subset of seismic stations at the summit of Kīlauea Volcano.

A view of the northern Overlook crater wall, through passing fume. ...
June 4, 2017

Different textures on the surface of the summit lava lake

Tracking the latest moves of Kīlauea and Mauna Loa...
June 1, 2017

On the Island of Hawai‘i, deformation is measured primarily with three techniques: tiltmeters, GPS (Global Positioning System), and InSAR (Interferometric Synthetic Aperture Radar).

This video clip shows HVO geologist Tim Orr sampling lava from an a...
May 31, 2017

Hawaiian Volcano Observatory and Jaggar Museum

Numerous fumaroles are present near the rim of Halema‘uma‘u Crater,...
May 28, 2017

Spattering on summit lava lake and Pele's hair around Halema‘uma‘u

A close up of one of the typical pāhoehoe toes. ...
May 27, 2017

Sluggish breakouts near the base of the pali

Volcanoes, Landslides, and Angry Gods—A Pacific Northwest Connectio...
May 25, 2017

Both volcanoes and landslides are important for landscape evolution in Hawaii and worldwide. In Washington State, an old legend makes the connection between them.