Quantcast
StarBulletin.com
Wednesday, November 25, 2009

Search

HiLife Online

Give us YOUR Weekly Opinion

Reader Poll

How much will you spend on Christmas presents this year?

Sell your stuff in Hawaii classifieds
Subscribe to the Honolulu Star-Bulletin

Big Isle well strikes deep lava chamber

Magma flowing into a shaft was the first seen in its "natural habitat"

By Rod Thompson

POSTED: 01:30 a.m. HST, Dec 22, 2008

(Single Page View) | Return to Paginated View

HILO » Geologists around the world are perking up at the news from San Francisco last week that magma flowed a short distance into a Big Island geothermal well during drilling in 2005, revealing an unusual mineral.

Geologists on the Big Island are taking the news more calmly since they were informed months earlier, and a much more dramatic case of magma in a geothermal well took place in Iceland in 1977.

"Encountering magma when drilling into the rift zone of an active volcano is not unexpected," said Jim Kauahikaua, head of the Hawaiian Volcano Observatory.

The Big Island incident involved magma entering the bottom 20 feet of an 8,300-foot-deep well, said Mike Kaleikini, manager of Puna Geothermal Venture.

The Iceland incident involved magma rising the entire length of a 3,734-foot well and spilling onto the surface, according to a 1979 Nature magazine article by Icelandic scientists. The brief surface flow was estimated at 3 tons or roughly three pickup trucks full.

The Big Island magma event was announced Tuesday at a meeting of the American Geophysical Union. It was disclosed by Johns Hopkins University geologist Bruce Marsh, who works with geologist Bill Teplow of Puna Geothermal affiliate Ormat.

Marsh said the delay in the announcement happened because Ormat searched for two years for a scientist who would be interested before finding him.

Kauahikaua described Marsh as the highly respected "kupuna of magma chambers."

Marsh said the Big Island incident was the first time magma had ever been seen in its "natural habitat" underground.

Kaleikini said drilled rock fragments were carried to the surface by special drilling fluid.

The incident began with "torque," meaning difficult drilling, he said. Drillers pulled the drill bit back about 40 feet and started again, but discovered the hole was 20 feet shorter than moments earlier.

When new chipped rock reached the surface, it was white rather than the normal black. The white rock turned out to be dacite, very unusual in Hawaii, indicating a high percentage of silica, Kaleikini said.

Marsh called the dacite find "very special."

Kauahikaua said the silica probably came from other substances in the magma crystallizing out, leaving the silica behind.

Puna Geothermal successfully used the well to pump used geothermal water back into the ground.

HILO » Geologists around the world are perking up at the news from San Francisco last week that magma flowed a short distance into a Big Island geothermal well during drilling in 2005, revealing an unusual mineral.

COURTESY HAWAIIAN VOLCANO OBSERVATORY
Lava from Kilauea enters the sea at Waikupanaha, generating a large plume, as shown in this photo taken Friday, and small explosions, according to the U.S. Geological Survey. Further upslope, in the Puna rain forest, geothermal drills hit a magma chamber in 2005.

Geologists on the Big Island are taking the news more calmly since they were informed months earlier, and a much more dramatic case of magma in a geothermal well took place in Iceland in 1977.

"Encountering magma when drilling into the rift zone of an active volcano is not unexpected," said Jim Kauahikaua, head of the Hawaiian Volcano Observatory.

The Big Island incident involved magma entering the bottom 20 feet of an 8,300-foot-deep well, said Mike Kaleikini, manager of Puna Geothermal Venture.

The Iceland incident involved magma rising the entire length of a 3,734-foot well and spilling onto the surface, according to a 1979 Nature magazine article by Icelandic scientists. The brief surface flow was estimated at 3 tons or roughly three pickup trucks full.

The Big Island magma event was announced Tuesday at a meeting of the American Geophysical Union. It was disclosed by Johns Hopkins University geologist Bruce Marsh, who works with geologist Bill Teplow of Puna Geothermal affiliate Ormat.

Marsh said the delay in the announcement happened because Ormat searched for two years for a scientist who would be interested before finding him.

Kauahikaua described Marsh as the highly respected "kupuna of magma chambers."

Marsh said the Big Island incident was the first time magma had ever been seen in its "natural habitat" underground.

Kaleikini said drilled rock fragments were carried to the surface by special drilling fluid.

The incident began with "torque," meaning difficult drilling, he said. Drillers pulled the drill bit back about 40 feet and started again, but discovered the hole was 20 feet shorter than moments earlier.

When new chipped rock reached the surface, it was white rather than the normal black. The white rock turned out to be dacite, very unusual in Hawaii, indicating a high percentage of silica, Kaleikini said.

Marsh called the dacite find "very special."

Kauahikaua said the silica probably came from other substances in the magma crystallizing out, leaving the silica behind.

Puna Geothermal successfully used the well to pump used geothermal water back into the ground.

(Single Page View) | Return to Paginated View



Story tools

Email  Email   Print  Print   Save  Save   Popular  Most Popular   Reprint  Subscribe

Share this story