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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Lava spilling over sea cliff starts to build new lava delta, Kīlaue...
August 23, 2005

Lava spilling over sea cliff builds new lava delta, Kīlauea

pāhoehoe lava spilling over sea cliff on south coast of Kīlauea Volcano starts to build a new lava delta. Only three days old, the delta grows slowly as lava spreads over fragmented debris and flows that have accumulated on the steep submarine slope.

Tephra-jet explosion at leading edge of an active lava delta, Kīlau...
August 19, 2005

Tephra-jet explosion at leading edge of an active lava delta, Kīlauea

Explosive interaction between lava and seawater blasts a tephra jet consisting of steam, hot water, black tephra, and molten fragments into the air. Such explosions are typically directed toward the sea, but many explosions also send a shower of lava more than 10 to 20 m (33 to 66 ft) inland. Tehpra jets are the most common type of lava-seawater explosion, and typically

Active lava delta on the south coast of Kīlauea Volcano, Hawai‘i...
August 12, 2005

Active lava delta on the south coast of Kīlauea, Hawai‘i

Active lava delta at East Lae‘apuki on the south coast of Kīlauea Volcano. White gas plume (right) marks location of lava entering the sea through a lava tube whose location is shown by blueish fume (left and center). In early August 2005, the delta encompassed an area of about 12 hectares (30 acres). On August 27, about 4.5 hectares (11 acres) of the delta collapsed into

Radio telemetry tower on Mauna Kea
July 5, 2005

Radio telemetry tower on Mauna Kea

A VHF radio receiving tower is set up on the slopes of Mauna Kea volcano on Hawai‘i Island, Hawai‘i. This setup allowed researchers to track radio tagged palila over large areas to determine where they were spending their time. 

May 10, 2005

Lava Pond Spattering and Overflow at the MLK Vent

(May 10, 2005, 16:20:29 to 18:30:29) After the collapse of the main spatter cone at the MLK vent (see movies "Spatter cone collapse at the MLK vent"), a small lava pond was visible within the new pit. At times, the level of the lava pond rose abruptly, overflowing the rim of the pit. This movie is an example of this and shows the lava surface rising suddenly to overflowing

May 2, 2005

Spatter Cone Collapse at MLK Vent

(May 2, 2005, 05:30:04 to 07:30:02) During spring 2005, activity at the MLK vent, on the southwestern flank of the Pu‘u ‘Ō‘ō cone, changed from a period of construction to one of destruction. This was highlighted by the collapse of the main MLK spatter cone. The drain-back of lava beneath the spatter cone, following lava extrusion, apparently removed support of the

May 2, 2005

Spatter Cone Collapse at MLK Vent

(May 2, 2005, 02:30:28 to 07:30:37) The spatter cone collapse described in the movie below was also recorded by a time-lapse camera on the west flank of the Pu‘u ‘Ō‘ō cone. This camera was located about 70 meters from the MLK vent and recorded two pulses of lava effusion from the vent before collapse. The first, and larger, pulse of effusion was abruptly terminated by a

February 10, 2005

Lava Fountaining from the MLK Vent

(February 9, 2005, 18:00:30 to February 10, 2005, 08:00:31) On February 9, 2005, an increase in lava discharge from Pu‘u ‘Ō‘ō, part of a longer term increase in effusion rate (Miklius and others, 2006), resulted in vigorous spattering and low fountaining from the MLK vent. Before the event, the tallest of the small complex of spatter cones over the MLK vent was about 6–7

Poster laid out with photos, images, and text.
December 31, 2004

Island-hopping Coral Larvae in Hawaii

Large-scale poster describing USGS work.

Scientists from the USGS, the University of Hawaii (UH), and Maui tracked the movements of reef-building coral larvae near Maui, Hawaii. We built and used “drifters”—floating instruments with radios and GPS receivers that drift in the currents with the coral larvae. We released the drifters when the corals released their

March 2, 2004

Pu`u 'Ō`ō Crater Lava Flow

(March 2, 2004, 11:48:17 to 23:08:42) Late 2003 through early 2004 marked a period of heightened eruptive activity at Pu‘u ‘Ō‘ō (Miklius and others, 2006) on Kīlauea Volcano's east rift zone, with lava frequently spilling from vents within the Pu‘u ‘Ō‘ō crater. This time-lapse movie, captured by a Webcam located on the northern rim of Pu‘u ‘Ō‘ō, shows lava erupting from a 

February 26, 2004

PubTalk 2/2004 — Life and Death of Hawaiian Coral Reefs

New Studies Track the Life Cycle of Maui's Changing Reefs

By Michael E. Field, Marine Geologist & Curt D. Storlazzi, Coastal Oceanographer

  • How are coral reefs changing, and why is it a concern?
  • Agents of change on Maui's reefs have both natural and human causes
  • Coral eggs and sperm released during
Nene goose stands among coastal vegetation
February 18, 2004

Nene goose stands among coastal vegetation

A nene goose, Hawai‘i's state bird and an endangered species, stands among coastal vegetation on O‘ahu island. USGS researchers have tracked nene movements using GPS transmitters to determine where they spend their time and to inform policy and decision making regarding their continued protection under the Endangered Species Act. 

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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.

October 10, 2002

In the Volcano Watch article two weeks ago, we broke the news that the summit area of Mauna Loa is swelling for the first time since 1993. If this trend continues, we're on track for the next eruption.

October 3, 2002

Many streams of lava entering the ocean are shattered to bits in the surf zone. These loose fragments gradually build layers of rubble on the steep submarine slope. The resulting nearshore submarine deposits are complexly interbedded lava flows and fragments ranging in size from boulders to tiny shards of glass and minerals.

Skylight, Kīlauea Volcano, Hawai‘i...
September 27, 2002

Skylight, Kīlauea Volcano, Hawai‘i.