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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Kamoamoa Eruption...
March 9, 2011

Map showing the extent of the active flows of the Kamoamoa eruption, which started on March 5, 2011.

Image: July 2007 Eruption--Quarry flow near-view map: July 27, 2010
February 4, 2011

Map showing a close-up view of flow field expansion over the past few days.

July 2007 Eruption—Flow Field Map...
February 4, 2011

Map showing the extent of the "July 2007 eruption", or Episode 58, flow field relative to surrounding communities.

Halema‘uma‘u Vent Map...
February 1, 2010

Map showing the location of the Halemaʻumaʻu Overlook vent, and subsequent closures due to the eruption.

Aerial view of Pu‘u ‘Ō‘ō and vicinity...
November 1, 2009

Aerial view of Puʻu ʻŌʻō and surrounding features. 

Episode 56 Map (with Seismicity)...
June 20, 2007

Map shows activity from Episode 56.

Map of flows from Pu‘u ‘Ō‘ō: September 12, 2003...
September 12, 2003

Map shows lava flows erupted during 1983-present activity of Pu‘u ‘Ō‘ō and Kupaianaha. Red colors, both dark and light, denote Mother's Day flow, which began erupting on May 12, 2002 and continues to the present. The darkest color represents flows active since January 21, 2003.

Pu‘u ‘Ō‘ō cone and surroundings as of July 2000...
July 1, 2000

Pu‘u ‘Ō‘ō cone and surroundings as of July 2000, showing the area covered (mauve color) by lava since February 1997 during episode 55. Inside the crater of Pu‘u ‘Ō‘ō, the "trough" is the drained lava pond of September–October 1999. The central portion of the trough was briefly filled with lava in February 2000.

Pu‘u ‘Ō‘ō cone and surroundings as of March 2000...
March 1, 2000

Pu‘u ‘Ō‘ō cone and surroundings as of March 2000 showing the area covered (dark gray) by lava since February 1997 during episode 55. Inside the crater of Pu‘u ‘Ō‘ō, the "trough" is the drained lava pond of September–October 1999.

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June 18, 2018

USGS Status Update of Kīlauea Volcano - June 18, 2018

USGS Hawaiian Volcano Observatory, Status of Kīlauea Volcano, 10:00 a.m. HST, June 18, 2018, Liz Westby - USGS Geologist

Kīlauea lower East Rift Zone lava flows and fissures, June 18, 9:00...
June 18, 2018

Kīlauea LERZ lava flows and fissures, June 18, 9:00 a.m.

Map as of 9:00 a.m. HST, June 18, 2018. Given the dynamic nature of Kīlauea's lower East Rift Zone eruption, with changing vent locations, fissures starting and stopping, and varying rates of lava effusion, map details shown here are accurate as of the date/time noted. Shaded purple areas indicate lava flows erupted in 1840, 1955, 1960, and 2014-2015.

Crater slumping with cracks
June 18, 2018

Kīlauea Volcano — Halema‘uma‘u Crater Slumping

An overflight of Kīlauea's summit on June 18 showed the continued dramatic slumping and collapse of the Halema‘uma‘u crater area. This photo shows the area north-northwest of Halema‘uma‘u near a GPS station, North Pit. This station has subsided about 60 m (197 ft) in the past week. 

Geologist test temperature reading of a fissure crack
June 18, 2018

Kīlauea Volcano — Thermal Camera Measurement

An HVO geologist uses a thermal camera to measure the temperature (about

Looking at a crater with steam rising from cracks
June 18, 2018

Kīlauea Volcano — Halema`uma`u Crater

North side of the growing Halema‘uma‘u crater, marked by large cracks and large blocks that have slumped into the crater.

June 18, 2018

Kīlauea Volcano — Weak Plume at Halem`uma`u (webcam)

On June 18, 2018, at 6:13 AM, a seismic event occurred at Halema‘uma‘u that produced a relatively ash-poor gas 

plume rising from ocean entry
June 17, 2018

Kīlauea Volcano — Vacationland Laze Plume

Lava enters the ocean entry in the vicinity of Vacationland, producing a vigorous laze plume. Lava flowing into the ocean has built a delta of flows, rock rubble and black sand, which is over 320 acres in size.

Crater in the distance
June 17, 2018

Kīlauea Volcano — Halema`uma`u Crater

Inward slumping of the rim and walls of Halema‘uma‘u continues in response to ongoing subsidence at the summit. Sulfur dioxide emissions from the volcano's summit have dropped to levels that are about half those measured prior to the onset of the current episode of eruptive activity. This gas and very minor amounts of 

View of lava channels
June 17, 2018

Kīlauea Volcano — Lava Channels

Occasionally, minor amounts of lava briefly spill over the lava channel levees. The spill overs are the shiny gray lobes along the channel margins. The lava flow field has been relatively stable with little change to its size and shape over the past few days. View to the east, with the 

Aerial of Fissure 8
June 17, 2018

Kīlauea Volcano — Fissure 8

Morning overflight of Kīlauea Volcano's lower East Rift Zone by the Civil Air Patrol provides context for the location of the 

June 17, 2018

Kīlauea Volcano — Fissure 8

In this video taken from the Leilani Estates subdivision, lava at 

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The March 5 breakout of the 61g flow is producing active surface fl...
May 23, 2017

61g flow is active at the Kamokuna ocean entry and at the base of the pali

Side-by-side comparison of the northwest wall of Kīlauea Caldera on a clear day (left) and a day with thick vog (right).
May 18, 2017

Just like smog and fog, this EarthWord is not what you want to see while driving...

HVO's website makeover is more than skin deep...
May 18, 2017

A new structure allows for a more efficient and consistent website, with simplified maintenance that leads to fewer broken links.


A geologist remembers the Mount St. Helens eruption 37 years ago...
May 11, 2017

This week's Volcano Watch was written by USGS Hawaiian Volcano Observatory geologist Don Swanson, who worked on Mount St. Helens before and after the 1980 eruption.

A clear day provided a stunning view of Mauna Loa's summit...
May 9, 2017

USGS scientists hiked to the summit of Mauna Loa, where they checked on HVO's monitoring instruments and realigned an antenna that allows webcam images of the volcano's summit caldera (shown in this panoramic image) to be posted on the HVO website.

A telephoto lens provided a close-up view of the seaward edge of th...
May 7, 2017

Lava delta at Kamokuna ocean entry is rebuilding

HVO transforms stacks of paper earthquake records into digital squi...
May 4, 2017

With funding from USGS data rescue initiatives, HVO scanned seismograms from a number of significant earthquakes and seismic sequences. Since last summer, volunteer Marcy Frenz has enthusiastically and diligently assumed scanning duties at HVO, working through the 1974–1984 interval spanning Mauna Loa Volcano's two most recent eruptions.

Within five minutes, between 9:55 and 10:00 a.m. HST, nearly the en...
May 4, 2017

Kamokuna lava delta: collapse on May 3 and how it looked today

By mid-afternoon, when these photos were taken, the drop in the lav...
April 27, 2017

Delta at the Kamokuna ocean entry slowly growing

Fissure of lava fountains erupting from Mauna Loa's upper southwest...
April 27, 2017

On June 13, 1950, Honolulu was suddenly blanketed by the thickest haze seen since recordkeeping began there in 1906.

A healthy coral reef at Buck Island, U.S. Virgin Island
April 20, 2017

In the first ecosystem-wide study of changing sea depths at five large coral reef tracts in Florida, the Caribbean and Hawai’i, U.S. Geological Survey researchers found the sea floor is eroding in all five places, and the reefs cannot keep pace with sea level rise. As a result, coastal communities protected by the reefs are facing increased risks from storms, waves and erosion.

HVO volunteer Ben Gaddis receives the "Citizen's Award for Exceptio...
April 20, 2017

Ben Gaddis was recently honored by the U.S. Geological Survey for his many years of service as HVO's volunteer photo archivist.