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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Image: Looking Southeast Along Kilauea TEB Tube System
July 1, 2010

Looking Southeast Along Kilauea TEB Tube System

View looking southeast along the fuming trace of the TEB tube system. The growing rootless shield field is in the background just above and to the left of center frame. The low, rounded shape of the shields--especially the shield in shadow to the left--are evident in this photo.

June 11, 2010

Action within Pu`u `Ō `ō crater

movie shows video taken during today's field visit and overflight. The first portion of the video is taken at the rim of Pu`u `Ō `ō crater, and shows the north vent feeding the lava pond. The lava surface undulates due to rising gas bubbles, and a small overturn is triggered. The second portion of the video shows an open stream of lava at the summit of one of the rootless

1940 was a momentous year for Mauna Loa - and for Thomas A. Jaggar ...
June 11, 2010

1940 was a momentous year for Mauna Loa - and for Thomas A. Jaggar

Lava fountains erupt from a fissure in the southwestern part of Moku`aeoweo, Mauna Loa's summit caldera, on April 11, 1940 (view looking to the south-southeast). Patches of white snow cling to the caldera walls as fluid pahoehoe lava flows spread across

Kīlauea plume: now you see it, now you don't...
June 11, 2010

Kīlauea plume: now you see it, now you don't

Kīlauea volcano's summit eruption plume as viewed from the southeast flank of Mauna Loa on 11/30/2009 (top) and 12/20/2009 (bottom). The eruption plume's visible appearance is a complex function of physical eruptive vent conditions, meteorology and atmosp

June 3, 2010

Active lava pond within Pu`u `Ō `ō crater

movie shows the active lava pond within Pu`u `Ō `ō crater, imaged with a thermal camera. The video is shown at x60 speed, and covers about 25 minutes. Lava is being supplied to the crater from two vents, one visible in the upper right corner of the image and one out of view in the lower left. Crustal foundering events, in which a section of the thin surface crust ruptures

Petrologic Monitoring of Kīlauea Volcano: An update for "Rockhounds...
June 2, 2010

Petrologic Monitoring of Kīlauea: An update for "Rockhounds"

An HVO geologist samples lava from an active lava tube. These samples are analyzed routinely to track changes in lava chemistry.

View of lava lake in Overlook vent, Halema‘uma‘u Crater, Kīlauea Vo...
June 1, 2010

View of lava lake in Overlook vent, Halema‘uma‘u, Kīlauea

This photo shows the view into Overlook vent during a relatively high level of the lava lake in 2010. When the lava was at a high stand like this, the plume became very thin and a view of the lava lake was possible. Typically, the fume was too thick to view the lava surface with the naked eye, and HVO geologists then relied on thermal cameras to image the lava surface.

June 1, 2010

Looking into the Halema`uma`u vent cavity

video from a thermal camera looking into the vent cavity at Halema`uma`u around 3pm today. The video is shown at x4 speed. At the beginning of the clip, the lava level is at a high stand, with slowly migrating crustal plates and little spattering. Eventually, small scale spattering begins in the northeast corner of the pond, accompanied by vigorous degassing. As the

Image: Thermal image of Kilauea viewing area
May 21, 2010

Thermal image of Kilauea viewing area

A closer view of the County viewing area, looking northeast. Again, the thermal image is shown together with a normal photograph. Recently emplaced flows, from the past several weeks, are light red (center of image). The currently active breakouts, just 250 yards northwest of the road, show up as white and yellow.

Image: Composite image of Kilauea viewing area
May 21, 2010

Composite image of Kilauea viewing area

This composite image overlays a thermal image on a normal photograph, and shows the flow field in the vicinity of the County viewing area, at the end of the Kalapana access road. Recent flows, from the past few weeks, show up as light red, whereas the currently active breakouts are yellow and white. One active finger of lava was just 250 yards northwest of the viewing area

Image: Aerial coastline of Kilauea
May 21, 2010

Aerial coastline of Kilauea

An aerial photograph looking west along the coastline of the current flow field. The Ki entry continues to produce a small plume, which is distributed along the newly formed delta. The color change in the ocean near the entry is due to the wave erosion of material from the delta and the lava itself.

Image: Flows Moving Through Kilauea Viewing Area
May 7, 2010

Flows Moving Through Kilauea Viewing Area

A closer view of the recent flows working their way down the road and through the trees. The viewing area has been moved back once again due to its proximity to the lava flows and potential fire hazards.

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December 19, 2002

Last month, some readers may have noticed a ship cruising back and forth off South Point and the South Kona districts of the Island of Hawai`i.

December 12, 2002

This is the season when the aroma of pine and fir greets KTA supermarket shoppers as they arrive to buy their fish and poi. Although more than 60,000 trees are imported for the Christmas season, Hawai`i is also home to some trees of its own that deserve hearty celebration.

USGS science for a changing world logo
December 6, 2002

Standard fare in geology textbooks and school classrooms across the world is that the hot springs, geysers and volcanoes of Yellowstone National Park, Hawaii, Iceland, and many other volcanic regions were "created" by plumes of hot rock that rise from near the Earth’s core. New results from recently published U.S. Geological Survey research hint, astonishingly, that such plumes may not exist.

December 2, 2002

Volcanoes have been in the news a lot lately: Etna (Italy), Reventador (Ecuador), Pago (New Britain, Papua New Guinea), Popocatepetl (Mexico)-even our own Mauna Loa. We usually hear about volcanoes only when one is erupting or getting ready to erupt. As a consequence, the news often makes volcanoes look pretty negative.

November 27, 2002

Friday, November 29, marked the 27th anniversary of the second largest earthquake to occur in Hawai`i. The magnitude-7.2 earthquake originated beneath the south flank of Kilauea Volcano, and that side of the volcano moved 8 m (26 ft) seaward and 3.5 m (11.5 ft) down. What caused the earthquake?

November 21, 2002

Many people remember that Mount St. Helens erupted with terrible ferocity on May 18, 1980, after a long dormant period. In fact, this is the date now used to mark the reawakening of the volcano. Yet it began to stir well before its activity reached a crescendo on May 18.

November 14, 2002

On November 3, one of the largest recorded earthquakes to strike the U.S. mainland rocked the interior of Alaska. The quake caused countless landslides, opened 1.8 meter (6-foot) cracks in highways, shook homes and damaged supports to the Trans-Alaska pipeline.

November 7, 2002

Air travelers to Hawai`i are familiar with the jet stream. The strong, high-level winds typically come from the northwest and slow west-bound flights by 30 minutes or more. Residents of Hawai`i returning from the mainland are frustrated by the jet stream; it takes longer to get home than to leave!

October 31, 2002

Several recent "Volcano Watch" columns have dealt with Mauna Loa and the implications of renewed inflation of its summit. For better or worse, this one will be no different except that it will be a "What if," rather than a "What is," topic. What if the lava flow produced in the most recent eruption of Mauna Loa had continued to Hilo? Where would the flow have gone?

October 29, 2002

When most people think of Hawaii, they think of a tranquil tropical paradise. But savvy Hawaiians know better: an old proverb says that "when the gales blow, the sea is white-backed; when the sea rises, corals are washed ashore."

October 24, 2002

A "Volcano Watch" article several weeks ago indicated changes occurring atop Mauna Loa. Specifically, global positioning system (GPS) receivers on Mauna Loa are showing that after eight years of steady contraction, extension is again occurring across the summit. Over 2 cm of the 7 cm lost to contraction since 1993 has been regained in the last five months.

October 17, 2002

Recent visitors to the coastal eruption site, especially those unwise enough to approach the flow margins where lava is encroaching on vegetation, are being greeted by a sometimes underrated volcanic hazard-the "methane" explosion.