Thursday, April 15, 2010

Strong magma pressures ~ Bright crater glow ~ Advancing surface flow

Click on the images for a larger size

The photo above is of the leading edge of the advancing surface flow of molten lava as seen looking south towards the coastal flats and the ocean beyond. The surface flow consists of a mix of more fluid-like pahoehoe and the jagged/chunky A`a type; both types, taken yesterday, are seen in the photo. The pahoehoe form of lava will likely dominate the flow as it reaches flatter ground further down. The public viewing area is located on the top upper left edge of the image where the remnant forest meets the open coastal plain; a distance of approximately 2 kilometers or about a mile and a half.

The advancing flow could be passing west of the viewing area in the days/weeks ahead. The lava is moving slowly at present, perhaps at a rate of 50-feet an hour, but that rate could change at any time.

After dark, reports from visitors to the Thomas Jaggar Museum within Hawaii Volcanoes National Park are of witnessing a very strong lava glow. A broiling lake of moving and molten lava with a base approximately 260 feet across and +/- 600 feet down inside a massive vent tube that reflects the lava colors up the vent and into the sulfur dioxide plume. The crater vents top opening is presently something like 460 feet in diameter and has been slowing growing in size since it first blew open in March 2007. Below is a saved image off the USGS Jaggar web cam last night and shows a very bright crater glow.

Lava pressures continue fairly steady and strong at both Halema’uma’u Crater, Pu`u O`o Crater and it’s adjacent eruption site. USGS HVO geologist say lava pressures beneath the Kilauea Volcano are often directly affected by changes in magma pressures within the large magma reservoirs below Kilauea. Sensitive tilt meter monitors placed strategically around the two craters record subtle bending/warping, or deformation of the crater’s rims. These changes are recorded constantly onto graphs, which the USGS kindly shares with the public on this page

Viewing Summary:
The most visual displays of active lava continue to be safely witnessed from the two designated public viewing areas:
1) The balcony outside the Jaggar Museum during the day and after dark. The Jaggar is located a few miles past the entrance gates of Hawaii Volcanoes National Park and is open to the public 24 hour a day, seven days a week.

2) The newly advancing surface flow can be watched from the Hawaii County Civil Defense public viewing area parking & trailhead, and also from the designated viewing area at the end of a 2200-foot walk across cooled pahoehoe lava. (Some sections of that lava walk are still warm from the October 23-26th. 2009 surface flow!). This surface flow is best seen after dark. Bring good footwear, some water and a flashlight if you plan to take the trail hike out to the county viewing area and stay after sunset. If you have binoculars bring those along. A typical nighttime view will look like the picture I posted on my previous blog report here

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