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: Sunrise on a Hawaiian Beach 1
June 9, 2007

Sunrise on a Hawaiian Beach 1

Just after sunrise on a beach in eastern Maui.

Image: Sunrise on a Hawaiian Beach 2
June 9, 2007

Sunrise on a Hawaiian Beach 2

Just after sunrise on a beach in eastern Maui.

October 28, 2006

Long-term Change at MLK Vent

(April 2, 2004, to October 28, 2006) A time-lapse camera was poised on the southwestern flank of Pu‘u ‘Ō‘ō cone from early 2004 through mid-2007. This location overlooked the "Martin Luther King" (MLK) vent, in the foreground (~70 m away), and provided a distant view of the top of the "Prince Kūhiō Kalaniana‘ole" (PKK) tube system—the Episode 55 lava tube system that

Active lava delta on south coast of Kīlauea, Hawai‘i
October 24, 2006

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

This lava delta at Lae‘apuki added about 24 hectares (60 acres) of new land to the southeast coast of Kīlauea in 2006, but 6.5 hectares (16 acres) slid into the sea in 2007. White plume marks location of lava entering the sea through a tube whose location is shown by blueish fume in middle right. The delta is covered with many recent surface flows (light gray) that escaped

October 16, 2006

East Lae‘apuki shatter ring

October 16 , 2006, 06:20:23 to 08:00:22) This is another movie showing a shatter ring in action (see "Shatter ring on the PKK lava tube", 03-20-06). This shatter ring, about 55 meters across and 2.5 meters high, grew between late September and mid-October, 2006, as a result of frequent breakouts from the PKK lava tube just inland from the East Lae‘apuki lava delta, like

September 22, 2006

Lava breakout from the PKK lava tube at East Lae‘apuki

(Sept 21, 2006, 18:00:02 to 00:00:05) Between the morning of September 20 and the evening of September 22, 2006, there were 10 separate breakouts from the PKK lava tube. Each originated about 50 meters inland from the older sea cliff bounding the inboard edge of the East Lae‘apuki lava delta. This movie shows the most spectacular breakout of the series, which fed up to at

Active lava delta, Kīlauea Volcano, Hawai‘i...
September 20, 2006

Active lava delta, Kīlauea, Hawai‘i

Lava pours over the former sea cliff at East Lae‘apuki onto an active lava delta (left of cliff). The lava broke out from a lava tube just inland of the sea cliff (right of photograph). Lava is also pouring over the cliff within a tube, indicated by the blueish fume rising from cliff behind the lava streams, and entering the ocean as shown by the white laze plume on edge

Researcher measures the wing of a palila nestling
July 18, 2006

Researcher measures the wing of a palila nestling

A very young palila nestling is given unique color bands and it's body measurements are taken on Mauna Kea volcano, Hawai‘i Island, Hawai‘i. In a multi-decadal study of palila and the factors influencing their population, Dr. Paul Banko has studied the diet, movement, and nesting behavior of these critically

June 24, 2006

Lava Breakout from PKK Lava Tube at East Lae‘apuki

(June 24, 2006, 19:00:53 to June 25, 2006, 01:00:55) After sunset on June 24, 2006, lava burst from the PKK lava tube about 50 meters inland from the older sea cliff bounding the inboard edge of the East Lae‘apuki lava delta. Lava reached the sea cliff and began cascading over it in less than a minute, and it spread quickly across the lava delta below. The cascade was

June 3, 2006

Gas Pistons Within Drainhole Vent at Pu‘u ‘Ō‘ō

(June 2, 2006, 18:30:02 to June 3, 2006, 02:00:03) Gas-pistoning is an interesting phenomenon seen at Kīlauea and some other basalticvolcanoes. It is caused by the accumulation of gas near the top of the lava column within a volcanic vent (Swanson and others, 1979). The shallow accumulation of gas causes the lava surface to rise (the "piston"). Eventually, the gas breaches

May 29, 2006

Lava Tube Bubble Bursts on the East Lae‘apuki Lava Delta

(May 29, 2006, 10:45:46 to 19:30:49) The interaction of sea water and lava creates a volatile situation (Mattox and Mangan, 1997). When this happens inside the confined space of a lava tube, or a narrow, water-filled crack, the results can be impressive. In this movie, lava bubbles, bursting from the top of the PKK lava tube, put on quite a show for several hours. Some of

Large cracks in active lava delta, Kīlauea Volcano...
May 19, 2006

Large cracks in active lava delta, Kīlauea

Substantial cracks cutting across a lava delta are clear indication that the delta is subsiding as it grows across the unstable pile of interfingering lava flows and fragments built on the steep submarine slope. The larger cracks on this delta are 1-2 m (3-6 ft) wide. Lava flows spread onto the delta from some of the cracks and then, after solidifying, were cut by renewed

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September 20, 2001

Forty years ago, at 12:36 p.m. on September 21, a swarm of large, shallow earthquakes accompanied by strong harmonic tremor began to emanate from the vicinity of Napau Crater on the east rift zone of Kīlauea Volcano. A rapid deflation of the summit of Kīlauea occurred in conjunction with the earthquake swarm.

September 13, 2001

The four youngest vents on West Maui erupted between 610,000 and 385,000 years ago. These newly determined radiometric ages remind us that sporadic small eruptions are possible on Hawaiian volcanoes even as they verge on extinction.

September 6, 2001

Nothing is constant except change. On August 17 the Kalapana road was reopened, allowing visitors access to a short trail and fine view point overlooking the active ocean-entry bench. Two weeks later, a narrow lava flowcrossed the road just east of the trailhead, and the road was closed. How did this happen, will it happen again, and what can be done about it?

August 30, 2001

Several decades ago, a person who had an overly active imagination might have been described as being "out in the ozone." Now just where would that be? Well, ozone (O3) exists in two distinct layers in the Earth's atmosphere and is considered "good" or "bad," depending on where it is. The US EPA has coined a maxim to help us remember: "good up high - bad nearby."

August 23, 2001

What is the summit elevation of Mauna Loa? 13,677 feet (4168.7 m) according to the 1994 Hawai`i Volcanoes National Park brochure; 13,679 feet (4169.4 m) according to the 1998 Atlas of Hawai`i; and 4,169 meters, which equals 13,678 feet, on the 1996 Geologic Map of the Island of Hawai`i. Who is right? Perhaps all?

August 16, 2001

At 2:00 p.m. on Friday, August 17, the County of Hawai`i officially opened to the public a new viewing area of the current eruptive activity. The viewing area overlooks the spectacular seascape of the lava bench and accompanying black sand beach at the ocean entry east of Kupapa`u.

August 9, 2001

What's the difference between a bench and a boardwalk? Both offer a view of the sea, but while the latter is a pleasant place for a stroll, a walk on the lava bench can kill you.

August 2, 2001

Every few months HVO receives a phone call from a concerned citizen explaining that steam is billowing from a new hole in a yard or pasture. Is this foretelling the start of an eruption?

July 26, 2001

Surfers of our Hawaiian Volcano Observatory (HVO) web site might have noticed that, earlier this year, we rolled out a modified web presentation of earthquake activity in Hawai`i. An "After Dark in the Park" evening talk at Hawai`i Volcanoes National Park in June also described our new web pages and their operation.

July 19, 2001

Every so often we receive a number of inquiries from anxious people in Kona about a possible eruption of Hualālai Volcano. The latest spate of questions is apparently being triggered by a personal web site that contains inaccurate information about the volcano. We hope to dispel the rumors by presenting the results of our ongoing observations.

July 12, 2001

The ground surface subsided abruptly about six weeks ago at Pu`u `O`o, Kīlauea Volcano's active cinder-cone vent. Gaping cracks opened around the edges of the subsidence zone, centered on the southwest edge of the cone. A collapse pit about 30 m (100 ft) in diameter and 15 m (50 ft) deep nibbled into the cone's margin. 

July 5, 2001

A visitor recently asked, "Does Kīlauea erupt more often at the summit or along its two rift zones?" Let's try to answer that question.