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Posted on: Thursday, December 1, 2005
Advertiser Science Writer
A 6-foot-thick stream of lava from Kilauea pours out of the side of a cliff at
Lae'apuki after a 34-acre lava bench sheared off and fell into the ocean. It was
the largest such collapse in the 22-year history of the volcano's current
eruption.
A 44-acre chunk of the Big Island's Puna coast collapsed into the sea with
high-energy pyrotechnics this week, exposing a 60-foot cliff face with a
spurting, 6-foot-thick red geyser of molten rock.
The fountain, shooting out of a lava tube that was ripped open by the big
collapse, is fast disappearing as the lava hardens around and under it and
begins forming a new coastal rock bench. "I'll be surprised if it lasts a week,"
said Jim Kauahikaua, head of the Hawaiian Volcano Observatory.
The collapse, about two miles from the end of Chain of Craters Road, began
shortly before noon Tuesday and continued for several hours. When it stopped, a
34-acre rock bench and 10 acres of the adjacent cliff had tumbled into the sea,
accompanied by explosions, flying gobs of molten rock, boulder missiles and
clouds of rare volcanic products known as Pele's hair and limu o Pele.
It was the largest bench collapse since the current eruption of Kilauea started
22 years ago. The previous record occurred at the same spot in 1996, when 26
acres of bench and eight acres of sea cliff rolled into the ocean. Benches occur
as a continual flow of lava runs onto the shoreline, building a rock shelf that
lies on an unstable bed of volcanic black sand and boulders. Kauahikaua said
cracks started forming at the inland part of the bench several months ago and
geologists began warning of an imminent collapse.
For several months, Hawai'i Volcanoes National Park has kept visitors well away
from the danger zone. They are allowed to walk a half-mile from a parking area
on a paved section of Chain of Craters Road, and then another third of a mile to
a lookout two miles from the active flow, said Jim Gale, chief of interpretation
for the park.
Even from that far away, the scene is spectacular, Gale said. "The cliff just
calved away like a glacier. It just sheared off that old wall. There's this
gigantic steam plume and you can see the red just falling down, an incredible
firehose display," he said. The cliff resulting from the collapse is 60 feet
high, and the lava tube is 15 feet below the cliff's lip, with the lava geyser
erupting 45 feet above the level of the sea.
Boulders up to the size of a human head extend inward nearly 300 feet. These
were hardened rocks that were blasted into the air and landed atop the cliff.
Rock dust, Pele's hair and limu o Pele extend inland 1,800 feet from the cliff's
edge. Pele's hair is thin strands of rock, formed when molten splatter is
exploded upward and spun in hot air currents, so it is stretched like taffy
until it hardens in fragile, hair-thin pieces that can be carried on the wind.
Limu o Pele forms when water enters an active lava tube. Steam instantly
stretches the molten rock into a balloon, before the surface hardens and
shatters, sending the thin sheets tumbling up into the air. The bits of limu o
Pele are so thin you can sometimes see through them, and in the afternoon sun,
they shine like gold on the surface of the land.
Kilauea Volcano has been erupting more or less continuously since Jan. 3, 1983.
St.
Helens, 25 Years Later
May 18, 2005
Watch Video
SEATTLE - Twenty-five
years ago, a News photographer had a hunch. Dave Crockett headed to Mount
St. Helens, pretty sure that "something" was going to happen.
Crockett was there on May 18th, 1980, when the mountain blew it's top and he continued to film as he witnessed what he called "Hell on Earth." On that Sunday morning, Crockett arrived to photograph a restless mountain that sill maintained its pristine, snow-capped peak.
"I really don't know how to describe it. It was just a feeling that something was going to happen," Crockett said.
At 8:32 a.m., the side of the mountain collapsed and the massive eruption began. "I knew I had to get out of there. I started down the valley, looked in my rearview mirror and there was just a wall of debris," Crockett said. "The whole valley was just disappearing behind me."
As Crockett tried to drive away, the road in front of him washed out. He was stuck.
"I just jumped out of my car and grabbed my film
camera," Crockett said. He pointed the camera toward St. Helens and captured
video of the massive ash plume moving overhead.
"I opened the (car) door and the alarm started going off, but it was kind of the
least of my concerns at that point," he joked while recounting the event.
As Crockett continued to film, debris began to flow around him as the ash cloud from St. Helens rose thousands of feet into the air.
"I had this huge cloud of material, lightning and blue and purple," he recalls. "I had to get away from that."
He began walking uphill, through the steaming mud and ash cloud. He turned on the camera and started to talk as ash turned everything around him to black.
"Dear God, whoever finds this," he says as only a sliver of light is visible. "You can't see this, I'm sure it's too dark, but I left the car behind. As you can tell probably from this picture, I'm walking towards the only light I can see at the top of a ridge."
He maintains a soft voice, but you can sense his desperation as he describes the scene around him while filming. "I can hear the mountain behind be rumbling. There's an enormous mud and water slide that came down and washed out the road."
"I never really thought I'd believe this or say this, but at this moment I honest to God believe I'm dead."
Crockett continues to narrate as the last bit of light disappears. "I can feel the ash now in my eyes. It's getting very hard to breath. I'm having trouble talking." "This is Hell on Earth I'm walking through."
As you hear him gasp for air between steps, his mood quickly changes. "I've got the wrong attitude here. This will be something to tell my grandchildren about," he says with a laugh.
As the breeze began to blow away some of the ash, Crockett was able to see
several feet in front of him. He stopped to take a photograph of himself smiling
amidst the grey devastation.
"I think you can tell from the expression on my face I thought then maybe I was going to get out," he said recalling the day. "When I finally realized I had made it and was going to live, I just started laughing and screaming out loud. I was just yelling at the mountain."
St. Helens would claim many lives that day. But not Dave Crockett.
Eruption At Mt. St. Helens
March 8, 2005
MOUNT ST. HELENS - A plume
billowing thousands of feet into air slowly drifted to the northeast Tuesday
as Mount St. Helens released a towering column of steam and ash.
The explosion happened around 5:25 p.m., about an hour after a 2.0 magnitude
quake rumbled on the east side of the mountain, said Bill Steele, coordinator of
the Pacific Northwest Seismograph Network at the University of Washington.
A substantial cloud clearly visible from Portland is rising above Mount St.
Helens
VANCOUVER, Wash. SKAMANIA COUNTY - Mt. St. Helens sprung back to life Tuesday
afternoon as perhaps
the largest eruption since the volcano became active again occurred at 5:25 p.m.
The plume was accompanied by an earthquake of about 2.0 magnitude.
Portland showed a large steam and ash plume rising as high as 15,000 to 25,000
feet from the volcano's crater.
UW Seismologist said that ironically, recent tests within the last few days
showed very low volcanic gas levels. They did record a slight increase in
average magnitude of quakes in and around the lava dome before the evening
eruption. Hours after the burst, the Weather Service received reports of light
ash falling across the Yakima Valley, roughly 75 miles east of the mountain.
Late Tuesday, the ash cloud continued to slowly drift east, across Yakima and
Kittitas County.
Steele said the largest hazard is to the aviation in the area, and the FAA is
likely working to get planes out of the way.
Clouds Clear And... Hey! Mt. St. Helens Burped
Again
January 22,
2005
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SEATTLE - In its latest explosion, Mount St. Helens blasted rocks and ash from the north end of its still-growing lava dome, sending a dusting of ash nearly 2 miles from the crater of the southwest Washington volcano.
But since that all happened at about 3 a.m. last Sunday, nobody saw the 17-minute "explosive emission," said hydrologist Carolyn Driedger of the U.S. Geological Survey at the Cascades Volcano Observatory in Vancouver, about 50 miles from the peak.
Scientists knew something had happened because the blast knocked out new instruments they had placed inside the crater just two days earlier.
"This is the kind of event that we knew could happen," Driedger said Friday. "We have this relatively placid dome-building ongoing since October, but we recognize that we can have these small explosions."
Taking advantage of a break in the clouds Wednesday, scientists took photos and checked out the latest event in the volcano's eruptive phase that began last fall.
Blocks of rock blasted from the vent could be seen embedded in the snow, Driedger said, estimating they were about 1 foot across. But scientists didn't want to get too close.
The explosion was similar to an Oct. 1 blast that was clearly visible, the USGS said. The volcano spewed clouds of ash and steam for five days, and molten rock began reaching the surface later that month, oozing out and building a new lava dome inside the crater.
The new dome has continued to grow but at a slower rate than last fall, the USGS said. Since Dec. 11, it has grown 100 meters or 330 feet in width, and 7 meters or 23 feet in height at its tallest point. It has remained 475 meters or 1,566 feet in length, constrained by the old lava dome and crater wall.
Low-level earthquakes, emissions of steam and gas and ash production have continued.
Searing-Hot Lava Giving Off Reddish Glow At Mt. St.
Helens
October 14, 2004
MT. ST. HELENS - Red hot lava
is steaming in the crater of Mount St. Helens as a lava dome on the volcano
grows a new lobe. The U.S. Geological Survey measured the hot rocks at 1300
degrees. The steam is drifting over the crater rim where it is dispersed in
strong winds. As they continue to monitor the mountain, scientists say an
explosive eruption is still possible. Although a 5-mile area around the volcano
is closed to the public, scientists says the glowing from the lava in the crater
could be visible from many vantage points.
Mt. St. Helens' Lava
Blob Increases In Size
October 13,
2004
The volcano continues to steam as lava over 1,100 degrees bubbles on the
surface.
MT. ST. HELENS - Mount St. Helens was still steaming Wednesday from glowing lava
in the crater of the volcano. The temperature of the lava extrusion is over
1,100 degrees. And the area of high temperature has increased in size.
October 12,
2004
MT. ST. HELENS - NEWS ALERT:
The U.S.
Geological Survey says a new lava dome is growing in the crater of Mount St.
Helens. Rocks are glowing with heat at about 1,000 degrees. That could mean
magma has reached the surface.
New thermal images reveal that parts of the lava dome in Mount St. Helens'
crater are piping hot, and scientists are seeing signs that magma continues to
rise. Scientists said an area on the south side of the old dome, where a large
uplift of rock has been growing, now appears perforated as if magma has been
hammering at the surface.
"What's happened in the last day is the magma is not just pushing up but pushing
out. No longer just isolated vents, instead the whole area is pushing up, the
gas is the fuse, just oozing out," Scientists have not actually seen the magma,
which they believe is less than half a mile below the surface. Fast-moving magma
would cause greater concern because explosive gases wouldn't have time to
dissipate. "Rapid assent is very dangerous, whereas if it rises slowly the magma
has a chance to degas and then it would just ease its way out,"
Scientists have said an eruption could occur with very little warning.
Temperatures in some spots could be as high as 200 to 300 degrees Celsius -
roughly 400 to 570 degrees Fahrenheit.
Readings taken during a Sunday flight over the volcano went off the charts.
"They didn't expect it to get that hot,"
Mt St.
Helen's Soap Opera
Mt. St. Helens' Crater Floor Continues To Rise
October 7, 2004
Scientists announced Thursday
MT. ST. HELENS - Scientists announced Thursday that they are once again refining
their prediction about the future of Mt. St. Helens, and that volcano has
entered a new eruptive phase, similar to the type of activity buildup that we
saw back in 1980.
And although scientists maintain it is a slim possibility, we could see a major
ash eruption as big as the main event in 1980, even if the mountain itself
doesn't experience as much of an explosion as 1980.
As to why?: Even though the earthquakes slowed down over the other day, the
scientists now know the bulge inside the crater continued to grow. It is now
higher than the older lava dome inside the crater, having grown 50 to 100 feet
since Tuesday and 250 feet since the mountain began stirring two weeks ago.
What that means is over the next days, weeks or months, we will likely see the
full gamut that this volcano has to offer. That means steam and ash eruptions,
lava flows, and lahars.
The ash and steam eruptions we've seen over the past few days would be rated a 0
or 1 on the volcanic eruption scale, which ranges from 0 to 8. The big eruption
in 1980 rated a 5 on the scale, and now, they're saying the most likely eruption
would be at about a level 3.
"The eruptive activity could go on for a significant period of time," "We think
that magma will very likely reach the surface very soon -- perhaps within days."
It may get a lot hotter in Portland soon!
Another Day,
Another Steam Release
October
5, 2004
MT. ST. HELENS - Mount St. Helens blew off a spectacular cloud of steam and ash on Tuesday, the biggest plume yet in days of rumblings and the latest indication that a larger eruption may be in the works.
Tuesday's burst sent a roiling, dark gray cloud 12,000 to 13,000 feet above the mountain before it streamed several miles to the northeast. The plume had "a significant amount of ash in it" but posed no immediate danger to humans or property as it rose rapidly above the 8,364-foot rim of the mountain.
The mountain has been venting steam daily since Friday amid a series of small earthquakes and volcanic tremors.
Earthquakes below magnitude 3 continued into Tuesday morning, and the 1,000-foot-high lava dome within the crater had swelled by about 150 feet. Geologists believe magma beneath the crater is pushing it upward.
"It is growing a lot," "It is growing very rapidly." Monday's 40-minute steam burst was almost entirely vapor rather than fresh volcanic material. Scientists were expecting steam bursts as superheated rock comes into contact with runoff from melting snow and ice. "Now most of us are convinced there's fresh magma (molten rock) down there". Runoff from a melting glacier formed a pond about 120 feet across just south of the dome in the crater, and it was bubbling at the center, Puckett said Tuesday. New cracks were developing in much of the dome and rocks as hot as 122 degree Fahrenheit tumbled off the growing mound and into the water.
Update:
St. Helens Eruption 'Imminent'
October
3, 2004
Scientists detected another volcanic tremor at Mount St. Helens early Sunday and
continued to warn that a major eruption was imminent.
MOUNT ST. HELENS - Scientists detected a volcanic tremor at Mount St. Helens
early Sunday, just hours after officials raised the volcano's alert level,
cleared hundreds of visitors from the area and warned a major eruption was
imminent. Sunday's tremor lasted about 25 minutes and was milder than the
50-minute tremor that followed a steam release Saturday, said Jeff Wynn, chief
scientist for volcano hazards at the U.S. Geological Survey's Cascade Volcano
Observatory.
"It just means that what's been happening is still happening" and the volcano is
moving toward an additional eruption. Scientists expect the impending blast to
be much smaller than the May 18, 1980 explosion that killed 57 people and coated
much of the Northwest with ash. But the tremors and steam detected since quake
activity began Sept. 23 signaled more seismic energy than at any point since the
1980 explosion.
Hazard Level Raised; Observatory
Evacuated Pressure Builds Again
October 2, 2004
SEATTLE - Government scientists raised the alert level Saturday for Mount St.
Helens after its second steam eruption in two days was followed by a powerful
tremor. They said the next blast was imminent or in progress, and could threaten
life and property in the remote area near the volcano.
Hundreds of visitors at the building closest to the volcano - Johnston Ridge
Observatory five miles away - were asked to leave. They went quickly to their
cars and drove away, with some relocating several miles north to Coldwater Ridge
Visitors Center
Mount St. Helens Erupts
Mahalo for Being Gentle
Pele'
October 1, 2004 The volcano that blew its top with
cataclysmic force in 1980 erupted for the first time in 18 years Friday,
belching a huge column of white steam and ash after days of rumblings. SEATTLE -
Mount St. Helens, the volcano that blew its top with cataclysmic force in 1980,
erupted for the first time in 18 years Friday, belching a huge column of white
steam and ash after days of rumblings. "This is exactly the kind of event we've
been predicting," said U.S. Geological Survey scientist Cynthia Gardner. Still,
the eruption was nowhere near what happened 24 years ago, when 57 people were
killed and towns 250 miles away were coated with ash. About 20 minutes after
Friday's eruption, the mountain calmed and the plume began to dissipate. The
eruption was so short-lived that the ash appeared to pose no threat to anyone.
No evacuations were ordered, and there was no sign of any lava pouring from the
volcano. The eruption occurred at 12:03 p.m. PDT, when there was a small
explosion, followed by the steam and ash cloud that rose from the southern edge
of the nearly 1,000-foot-tall lava dome. Steam frequently rises from the crater,
but the 8,364-foot peak had not erupted since 1986. The earthquakes quit after
the eruption. "That makes us think this is the end of the eruption," Qamar said.
"All this buildup was leading to that relatively small eruption." But USGS
seismologist Bob Norris said magma could be moving underground and he would not
be surprised to see more explosions in the next days or weeks. The plume had
reached 16,000 feet in altitude, but did not know whether any planes would need
to be rerouted. Alaska Airlines Diverts 4 Flights To Seattle From Portland
October 1, 2004 SEATTLE - The 24-minute eruption of steam and ash from Mount St.
Helens prompted Alaska Airlines on Friday to divert four planes on their way to
Portland International Airport to Seattle. "Our pilots are instructed and
trained not to fly through those plumes and they will not do that." Federal
officials contacted airline pilots heading toward Portland to let them know
Mount St. Helens was belching steam and ash. It's up to pilots and the airlines
they fly for to decide whether to reroute. "There are no two ways about it, you
don't want to be going through an ash plume," Fergus said. The National Weather
Service said it appears there was little ash in the plumes emitted by Mount St.
Helens. The Portland airport is about 50 miles away from Mount St. Helens. State
health authorities said any volcanic ash that may settle over Oregon after a
potential eruption of Mount St. Helens poses a very low health risk to
residents.
Energy 'Boiling Out' Of Mt. St. Helens
Chance Of Eruption At 70 Percent
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September 31, 2004
SEATTLE - The flurry of earthquakes at
Mount St. Helens continued Friday, and one scientist put the chance of a
eruption happening in the next few days at 70 percent.
Scientists said they believe the seismic activity is being caused by pressure
from a reservoir of molten rock a little more than a mile below the crater. That
magma apparently rose from a depth of about six miles in 1998, but never reached
the surface.
More infrared pictures Friday may indicate what may happen next at the volcano
where the earthquake swarms began more than a week ago.
September 30, 2004
SEATTLE - The flurry of earthquakes at Mount St. Helens intensified further
Thursday, and one scientist put the chance of an eruption happening in the
next few days at 70 percent.
Jeff Wynn, chief scientist at the U.S. Geologic Survey's Cascade Volcano
Observatory in Vancouver, Wash., said tiny quakes were happening three or four
times a minute. Larger quakes, with magnitudes of 3 to 3.3, were happening every
three or four minutes, he said. New measurements show the 975-foot lava dome in
the volcano's crater has moved 2˝ inches to the north since Monday.
"Imagine taking a 1,000-foot-high pile of rocks and moving it 2˝ inches. For a
geologist, that's a lot of energy," estimated there was a 70 percent chance the
activity will result in an eruption. Scientists did not expect anything like the
mountain's devastating eruption in 1980, which killed 57 people and coated towns
250 miles away with ash. On Wednesday, they warned that a moderate blast from
the southwest Washington mountain could spew ash and rock as far as three miles
from the 8,364-foot peak.
Few people live near the mountain, which is in a national forest about 100 miles
south of Seattle. The closest structure is the Johnston Ridge Observatory, about
five miles from the crater. The heightened alert has drawn a throng of
sightseers to observation areas.
A sign in front of a business reads, "Here we go again."
The Geological Survey raised the mountain's eruption advisory from Level 1 to
Level 2 out of a possible 3 on their four-leveled scale (from zero to 3)
Wednesday, prompting officials to begin notifying various state and federal
agencies of a possible eruption. The USGS also has asked the National Weather
Service to be ready to track an ash plume with its radar system.
In addition, scientists called off a plan to have two researchers study water
rushing from the crater's north face for signs of magma. A plane was still able
to fly over the crater Wednesday to collect gas samples. Negligible amounts of
volcanic gas were found.
They have been monitoring St. Helens closely since Sept. 23, when swarms of tiny
earthquakes were first recorded. On Sunday, scientists issued a notice of
volcanic unrest, closing the crater and upper flanks of the volcano.
Scientists said they believe the seismic activity is being caused by pressure
from a reservoir of molten rock a little more than a mile below the crater. That
magma apparently rose from a depth of about six miles in 1998, but never reached
the surface, Wynn said.
Movement Detected At St. Helens Lava Dome
September 29, 2004
Swarms of earthquakes - more than 1,000 since the mountain began stirring on
Thursday - have gradually increased to a level not seen since the last eruption.
SEATTLE - Scientists watching Mount Saint Helens say a
monitor indicates the lava dome in the crater has moved an inch-and-a-half. They
say that could mean pressure is building up in the volcano from gasses or magma
and that an eruption is possible within days. Scientist Jeff Wynn at the
Cascades Volcano Observatory in Vancouver cautions it will take at least 48
hours before scientists are more confident in the measurements.
A small explosion of rocks, ash and steam could occur within the next few days
within the crater of Mount St. Helens, where earthquake activity has been
steadily building for nearly a week. "It could certainly happen today; it might
not happen for weeks or months," said seismologist Seth Moran of the U.S.
Geological Survey's Cascade Volcano Observatory.
Scientists were keeping a close eye on the 925-foot-tall dome of hardened lava
that has grown inside the crater since the May 18, 1980, eruption that blew the
top off the mountain. Swarms of tiny earthquakes - more than 1,000 since the
mountain began stirring on Thursday - have gradually increased, cranking up to a
level not seen since 1986, when the volcano's last dome-building eruption
occurred.
Tuesday, the quakes were occurring at a rate of two or three a minute. The
volcano was releasing three to four times the energy it was releasing Monday,
said Jeff Wynn, chief scientist at the volcano observatory in Vancouver, Wash.,
about 50 miles south of the 8,364-foot mountain. Moran said that in an eruption,
rocks two or three feet in diameter could break off from the lava dome and
possibly be tossed as far as the rim. But, he and other scientists emphasized,
that's not unusual at Mount St. Helens.
Volcanologist said scientists are baffled by the activity, unusual because the
earthquakes are so shallow. "Where's the energy to keep driving this system?" he
asked at the Johnston Ridge Observatory at the base of the mountain, where
surrounding hillsides are still covered with trees toppled by the 1980 blast..
Largely unheralded steam explosions in 1989, 1990 and 1991 all broke pieces of
lava off the dome.
The likelihood of a significant eruption "is fairly small," Moran said. "There's
a range of possibilities still for where this may go. It might go away and
nothing happens. That becomes less likely as this continues to increase. At the
other end, we could have a reactivation of the lava dome-building sequences."
Scientists are "not sure where this is going and it's really hard to communicate
this succinctly," he said.
Seismologist George Thomas at the University of Washington said that on a scale
of zero to 10, with 10 being the explosion at the mountain in 1980, the current
activity would rate a one. Thomas said any rocks, ash or steam coming out of the
volcano would most likely be contained within the crater itself. "The alerts
we're sending out are just to protect hikers and scientists doing research
within the crater," he said.
Scientists are trying to determine if the quakes are caused by steam resulting
from water seeping into the dome or more seriously, by magma moving beneath the
crater. Early tests of gas samples collected above the volcano by helicopter
Monday did not show unusually high levels of carbon dioxide or sulfur. "This
tells us that we are probably not yet seeing magma moving up in the system,"
Wynn said.
The USGS issued a notice of volcanic unrest on Sunday. U.S. Forest Service
officials closed hiking trails above the tree line at 4,800 feet. The visitors
center and most other trails at the Mount St. Helens National Monument remained
open.
Mount St. Helens roared to life in 1980, when the massive explosion and
landslide obliterated the top 1,300 feet of the volcano. The blast and
subsequent mudflows killed 57 people, leveled hundreds of square miles of
forests, spewed mud and debris for miles and spread volcanic ash across much of
the Northwest.
The last dome-building eruption was in 1986, though steam explosions have
periodically rocked the dome.
Earthquake swarms in 1998 and 2001 did not result in any surface activity.
0535 September 30 Mauna Loa
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Mauna Loa, the world's largest volcano |
Thursday morning sees no changes at Mauna Loa. Since early July 2004, an increasing number of earthquakes has been recorded from beneath Mauna Loa. From week to week, the numbers fluctuate but remain well above the norm. Through the third week of September, more than 560 earthquakes were centered beneath Mauna Loa’s summit caldera and the adjacent part of the southwest rift zone. Most of these earthquakes are quite deep, from 35 to 50 km below the ground surface and small, less than magnitude 3. They are "long-period" (LP) earthquakes, which means that their signals gradually rise out of the background rather than appearing abruptly. Such a concentrated number of deep LP earthquakes from this part of Mauna Loa is unprecedented, at least in our modern earthquake record dating back to the 1960s.
Hawaii's Mauna Loa shows signs of erupting
Thanks for sending Robyn Monday, September 13, 2004 Posted: 8:56 AM EDT (1256 GMT)
KAILUA-KONA, Hawaii -- Earthquakes have been rumbling more frequently deep beneath Mauna Loa, suggesting that the world's largest volcano is getting ready to erupt for the first time in 20 years, scientists said.
"We don't believe an eruption is right around the corner, but every day that goes by is one day closer to that event," said Paul Okubo, a seismologist at the Hawaiian Volcano Observatory on the Big Island. Mauna Loa erupted for three weeks in 1984, sending a 16-mile lava flow toward Hilo. Since then, the U.S. Geological Survey estimates that more than $2.3 billion has been invested in new construction along Mauna Loa's slopes.
Since July, more than 350 earthquakes have been recorded far beneath the 13,677-foot-high Mauna Loa, said Don Swanson, scientist-in-charge at the observatory. "Mauna Loa is grumbling, growling and getting ready to come out of its den," he told West Hawaii Today for Sunday's editions. The earthquakes have been what seismologists call "long period," which means their signals gradually rise above the noise generated by usual seismic activity.
"Such a concentrated number of deep, long-period earthquakes from this part of Mauna Loa is unprecedented, at least in our modern earthquake catalog dating back to the 1960s," Okubo said. While forecasting an eruption cannot be exact, Okubo noted that the mountain today is wired with more state-of-the-art tracking and measuring technology than ever before.
The
definite sign of an impending eruption is an earthquake swarm -- a dramatic
increase in the number of daily tremors from a
handful, to dozens to ultimately hundreds, Okubo said. Mauna Loa is within
Hawaii Volcanoes National Park, which also
contains the well-known Kilauea volcano. Kilauea has been erupting continuously
since Jan. 3, 1983.
Located on the Big Island of Hawaii, Mauna Loa - or "Long Mountain" in Hawaiian - is the largest volcano in the world.
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Hawaiian legends say that volcano goddess Pele was driven from her home by
her angry older sister, Na-maka-o-kaha'i because Pele had seduced her
husband. Every time Pele would thrust her digging stick into the earth to
dig a pit for a new home, Na-maka-o-kaha'i, goddess of water and the sea,
would flood the pits. Pele eventually landed on the
Big Island, where she made Mauna Loa her new
home. Literally meaning "Long Mountain" in the Hawaiian language, Mauna
Loa was so tall that even Pele's sister could not send the ocean's waves
high enough on Mauna Loa to drown Pele's fires. So Pele established her
home on its slopes.
Kilauea, an active volcano sitting on the
mountain's southeast flank, has an extensive history of eruptions,
including the eruption in 1983 which blanketed 30,000 acres of land with
lava, and created 180 acres of new land offshore. $62 million dollars in
property damage was assessed from the eruption, and the lava from the
eruption continues to flow today. > |
Posted on: Tuesday, August 17, 2004
New pattern of minor quakes shakes Mauna Loa
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A lava flow inches along a beach at the foot of the eastern Banana delta. |
HILO, Hawai'i — Scientists are monitoring a series of earthquakes that has been rattling Mauna Loa in a pattern unlike any detected before at the world's largest volcano.
The summit of Mauna Loa has been inflating since 2002 in what scientists believe is a swelling of the underground magma reservoir and a signal of a coming eruption. Earthquake activity picked up before the past two eruptions in 1975 and 1984, but it is unlikely the recent series of temblors indicates an imminent eruption, said Paul Okubo, research seismologist at the Hawaiian Volcano Observatory.
"We're of the mindset here that Mauna Loa will erupt, but in terms of the lead time, I think we're still quite a ways off," he said.
The recent earthquakes are originating 25 to 30 miles below Mauna Loa's caldera, with the largest in the magnitude 2 range. It's unlikely anyone on the surface would feel temblors that small and deep, but scientists have catalogued about 50 similar earthquakes in the past three weeks, and the activity appears to be continuing, Okubo said. "We've not seen these before," he said. "It's a new pattern." Most earthquakes at Mauna Loa are more shallow, he said. There have been a significant number of deep earthquakes below Mauna Loa before, but never so many in such a short period of time as scientists have recorded since July, he said.
At Kilauea volcano, scientists have gathered evidence that links similar but shallower earthquakes to the movement of magma below the surface. But Okubo said scientists don't know what is causing the recent quakes under Mauna Loa. "We can locate them, we can determine their magnitudes, we can look at their behaviors through time, but in terms of really associating them with a physical process, we don't have that kind of handle on it," he said.
Larger and shallower earthquakes have been associated with Mauna Loa's past two eruptions.
In the summer of 1974, scientists noted a series of unusual, shallow earthquakes five to six miles below the surface, and recorded a magnitude 5.4 earthquake on Nov. 30, 1974. Mauna Loa erupted on July 5, 1975. A similar pattern of shallow earthquakes was observed by scientists in the fall of 1983, with a larger magnitude 6.6 earthquake on Nov. 16, 1983. The following March 26, Mauna Loa erupted again.
Both of the stronger, shallower earthquakes before the two eruptions were beneath the southeastern flank of Mauna Loa.
The recent deep earthquakes "are possibly among the very, very early indications of changes that will happen and begin to move more systematically shallower in the system."
Lava
flowing from Kilauea’s ongoing eruption finally made its way to the ocean once
again a couple of weeks ago. And for the first time in nearly a year, everyone
-- from curious park visitors and staff, to intent photographers, to nerdy
(and intent) volcanologists can have the enrapturing experience of seeing
liquid rock encounter ocean. This latest spectacle, however, also reminded us
of the unusual hazards posed by the interaction of hot lava and cool seawater.
Nearly a half dozen people have died at the coastal entry in the past 10 years
and scores more injured. Being prepared for the hazards can help to avoid
becoming part of these statistics.
Special Mahalo to Kelani for her photo donation as well as Alana in Pensacola
MAUNA LOA
