Videos

New ideas on Bay Area evolution from a decade of geologic mapping

By Russ Graymer, Geologist

Gas-pistoning is an interesting phenomenon seen at Kilauea and other volcanoes. It is caused by the accumulation of gas within, or the rise of a gas slug through, a column of lava. In either case, the gas pushes up the overlying lava (the "piston"). Eventually, the gas breaches the surface and escapes, sometimes as a forceful jet of fume and spatter.

(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 l

After sunset on June 24, 2006, lava burst from the East Lae'apuki lava tube about 50 meters (165 feet) inland from the older sea cliff behind the East Lae'apuki lava delta. Lava reached and began cascading over the sea cliff within a minute, and quickly spread across the lava delta below.

To document changes in the lava stream level within the Prince Kuhio Kalaniana'ole (PKK) lava tube, a time-lapse camera was placed on the brink of a lava tube skylight (an opening in the roof of the lava tube) with a view of the lava.

Cloud-top temperature simulation for Arctic Alaska

Surface air temperature simulation for Arctic Alaska

Total precipitation simulation for Arctic Alaska

Total precipitation simulation for Arctic Alaska

(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).

Gas-pistoning is an interesting phenomenon seen at Kilauea and other volcanoes. It is caused by the accumulation of gas within, or the rise of a gas slug through, a column of lava. In either case, the gas pushes up the overlying lava (the "piston"). Eventually, the gas breaches the surface and escapes, sometimes as a forceful jet of fume and spatter.

Gas-pistoning is an interesting phenomenon seen at Kilauea and other volcanoes. It is caused by the accumulation of gas within, or the rise of a gas slug through, a column of lava. In either case, the gas pushes up the overlying lava (the "piston"). Eventually, the gas breaches the surface and escapes, sometimes as a forceful jet of fume and spatter.

Gas-pistoning is an interesting phenomenon seen at Kilauea and other volcanoes. It is caused by the accumulation of gas within, or the rise of a gas slug through, a column of lava. In either case, the gas pushes up the overlying lava (the "piston"). Eventually, the gas breaches the surface and escapes, sometimes as a forceful jet of fume and spatter.

The first priority of any eruption is to assess current status and what might happen next. To accomplish this, Mount St. Helens became one of most heavily monitored volcanoes. At the start of the 2004–08 eruption, 13 permanent seismic stations operated within about 12 miles of Mount St. Helens.

Throughout the eruption, scientists installed monitoring stations to track volcanic activity, deployed temporary monitoring ""spiders"", monitored the temperature of lava spines and created time-lapse of dome growth. During the 3+ years of the eruption, lava piled up to form a new dome 460 m (1,500 ft) high.

(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.

The interaction of sea water and lava creates a volatile situation. When this happens inside the confined space of a lava tube, or a narrow, water-filled crack, the results can be impressive. In this video, which was made from time-lapse images cropped to focus on the activity, bursting lava bubbles put on quite a show for several hours.

Concealed sedimentary basins and hidden oil under Silicon Valley

By Richard G. Stanley, Geologist 

How historical data from 1906 have shed light on the San Andreas Fault

By Carol S. Prentice, Geologist 

This short excerpt is from a USGS/Bay Area Earthquake Alliance produced television program "Shock Waves: 100 Years After the 1906 Earthquake". This specific segment describes some of the history behind our modern understanding of the earthquake process. The program received numerous industry awards and was nominated for a regional Emmy Award in the Bay area.

Shock Waves is an Emmy Award nominated USGS television program that aired on San Francisco's CBS-5 in April, 2006 during the week of the 100 year anniversary of the Great San Francisco Earthquake. The program is hosted by Dana King and was produced and directed by Stephen M. Wessells.