Images

Distribution of young volcanic rocks by age in Haleakalā Crater, Maui.

CalVO geologists Duane Champion and Drew Downs collect paleomagnetic samples from basalt lava flows at Eagle Lake

Aerial view of Haleakalā Crater northward to Ko‘olau Gap. Sharp rimmed crater in near ground is Ka Lu‘u o ka ‘Ō‘ō.

Top: Photograph of the SO2 camera installation when scientists tested the radio link to the Hawaiian Volcano Observatory (HVO). The camera is aimed at the plume emitting from the Overlook Crater, about 1.4 km away. Under typical trade wind conditions, the plume is blown to the southwest, thus moving from right to left in the imagery.

Vent activity, typical of that in summer and fall 1969 between episodes of high fountaining. The spattering is from one of two compartments that contained lava. Typically lava levels in the two compartments were different, and gas pistons might work in both but at different times.

Map showing area covered by lava flows of Mauna Ulu eruption. Note that the map was made in 1997, before diacritical marks were being used in Hawaiian place names. The two colors designate the 1969-71 and 1972-1974 parts of the eruption, respectively. In the scale, 3 km is equal to about 2 mi.

Seismic hazard across the State of Hawaii, with high seismic hazards depicted with warm colors (red-orange) and relatively low seismic hazards depicted with cool colors (green). Engineers use these types of maps to prescribe building codes known as Seismic Design Codes (SDC) and create earthquake resistant structures.

Seismic station locations (red triangles) on the Island of Hawai‘i and across the State of Hawaii (inset).

Earthquakes near the Island of Hawai‘i between 1970-2006 with magnitude greater than 2.5. A (top left): locations of shallow earthquakes 0-22 km (0-14 mi) depth. B (top right): locations of deep earthquakes 22-55 km depth (14-34 mi). Bottom (C): cross section showing the depths of earthquakes in the rectangle in figure B.

Silica sinter (an amorphous form of silicon dioxide) forms from the waters that flow from hot springs near Shoshone Lake, Yellowstone National Park. USGS photograph by Jake Lowenstern.

The Uwekahuna WT (water-tube) instrument is still measured today, providing one of the longest records of deformation for any volcano. The tiltmeter is read by looking into the portal on each pot and adjusting the sight until two pins appear to touch.

Slope map of Mauna Loa, including lava flows erupted since 1823 (gray), showing the approximate number of hours or days it took for a flow to advance from the vent location to the ocean or maximum reach of a flow. One flow that moved down the steep slopes on west flank of Mauna Loa reached the ocean in as little as 3 hours after the vent started erupting in 1950.

This notice was posted at campgrounds around Baker Lake by the US Forest Service in June 1975. Normally, Baker Reservoir approaches capacity during mid-summer. At most other times, reservoir levels are low enough to impound lahars the size of those that occurred in 1843.

Mount Baker's crater lake in 1976 formed due to glacial and snow melt as a result of increased heat from magma beneath the surface. Fumarole on left ejecting gas at a velocity of 268 kph (167 mph).

Mount Hood dominates the skyline outside of Portland, Oregon on a clear day. An major eruption of Mount Hood would pose a great hazard to the regional economy.

Mount Hood in the not-so-far distance beyond Downtown Portland, Oregon. Photograph taken at the top of the Portland Aerial Tram line on Marquam Hill.

Crater Lake, Oregon simplified hazards map showing potential impact area for ground-based hazards during a volcanic event.

Mount Adams viewed from the southeast in Klickitat Valley, Washington.

Family Emergency Preparedness Plan

Glacier Peak volcano, Washington reflected in pond below the Whitechuck Glacier, view from the south in late summer.

Remnant of Villard Glacier is in cirque below. Thick summit lava flow makes up "Glisan Pinnacle," which overlies hundreds of thin rubbly lava flows that are intercalated with red-oxidized agglutinate and scoria falls exposed on 800-m- (2600-ft-) high face below. Flows that form ridge at upper right are thicker than those on most of edifice.