Saturday, September 13, 2008

Facelift for Mirage's volcano

Real volcanos may take millennia to form, but in Las Vegas they can take just 20 years to look dated.

That's what The Mirage hotel-casino concluded before it mounted a $25 million facelift of its iconic erupting volcano on the Las Vegas Strip.

The faux rock fountain first erupted in 1989 and its bursting spray of water lighted red to look like lava is among the city's classic sights for strolling pedestrians. The volcano was among the flashiest early casino spectacles — added to deliver whimsy, wow factor and gamblers.

Still, the casino concluded, it could be so much more.

The volcano is getting 120 new fireball-throwing devices that will be choreographed to erupt in sync with a rumbling drum score co-composed by former Grateful Dead drummer Mickey Hart and piped into the desert air through a high-tech sound system, according to company officials who will officially announce renovation details Wednesday.

The project won't be completed until later this year.

Some of the fireball devices will spout gas flames 12 feet in the air, while others ooze fiery "lava" down the volcano's crevices. The flames will appear to burst close to passers-by — but not too close.

"It looks dangerous, but in reality it's not. We just want people to stand back on their heels," said Jim Doyle, the director of new technologies at the Sun Valley, Calif.-based design firm WET.
WET is perhaps best known as the firm behind the Bellagio hotel's fountains, and Doyle acknowledges the dancing water jets just down the Strip were an inspiration for the volcano's new look.

He spent two years developing a fire-shooting device that could sleep in the volcano's surrounding lagoon during the day and emerge at night for hourly shows. The miniature robots can be choreographed, but in the foreseeable future the fireballs will dance to Hart's score, he said.

Along with longtime creative partner Zakir Hussain, Hart said he brought in dozens of instruments to reinterpret the sound and the vibration of "the Earth belching."

"It's our version of a birthing of a volcano, which is filled with a lot of different kinds of emotional content, anticipation and anxiety. It's filled with magic and power," Hart said. "You might even be able to feel the lava coming down on top of you."

This bigger, better volcano is the last piece of the 20-year-old resort's recent overhaul. Owner MGM Mirage Inc. has spent $110 million upgrading rooms and suites at The Mirage, as well as adding a new nightclub, restaurants and the Cirque du Soleil's Beatles-themed "Love."

Mirage President Scott Sibella said he wished the property's signature feature was a little closer to the new indoor attractions. Since the volcano first erupted, casinos have learned to put such features inside to bring people closer to their casinos.

Sibella said The Mirage may someday add a bridge connecting the street-level volcano to the casino entrance.

"It does draw thousands of people for every eruption," he said, "but the challenge is getting them inside the property."

On the Net:
http://www.mirage.com

Volcano eruptions in Alaska keep everyone's attention

Explosive eruptions on three remote Aleutian islands this summer during a three-week period generated large ash and gas-rich clouds that kept scientists at the Alaska Volcano Observatory (AVO) extremely busy assessing the activity and issuing warnings about the hazards.The first eruption of the summer occurred with very little warning on July 12 at Okmok Volcano, Unimak Island, 1,383 kilometers (859 miles) southwest of Anchorage.

Okmok's most recent eruption in 1997 produced low-level ash clouds and a lava flow that traveled about 8 kilometers (5 miles) across the volcano's broad caldera floor.An ash and gas cloud from initial explosive activity moved southeast over a broad area of the Gulf of Alaska and caused flights to be re-routed for a few days. The explosive activity continued for several weeks, sending volcanic ash and gas to heights between 10,000 and 35,000 feet above sea level. Nine people evacuated from a cattle ranch on Unimak Island.

A volcano-monitoring network was installed on Okmok in 2002-2003 as part of the effort by AVO to monitor an increasing number of active and potentially active volcanoes in Alaska. Only local monitoring networks permit the early detection and measurement of volcanic unrest, assessment of activity during an eruption, and effective warnings of eruptions.

Today, 31 volcanoes in Alaska are monitored with ground-based instruments, compared to four in 1989.Next, Cleveland Volcano, 160 kilometers (100 miles) west of Okmok, generated a short-lived explosive eruption on July 21. During the next several days, when the volcano was visible through clouds, pilot reports and satellite information indicated low-level ash emissions 10,000 to 20,000 feet above sea level. This activity is similar to brief eruptions in 2001 and 2005-2007.The lack of a real-time seismic network at Cleveland means that scientists are unable to track local earthquake activity related to volcanic unrest.

Only satellite data is used by AVO scientists to detect and track significant ash clouds (when weather allows) or identify new thermal features.After four weeks of around-the-clock monitoring of Okmok and Cleveland volcanoes, the largest explosive eruption occurred at Kasatochi volcano on Aug. 7, resulting in a large ash and gas cloud that spread southeastward across the Gulf of Alaska, Canada, and the northern United States.

Many airline cancellations and enroute diversions were made to avoid the volcanic cloud. On Aug. 10, dozens of flights were cancelled from Anchorage to Los Angeles, Denver, and Vancouver, B.C., stranding more than 6,000 passengers.Three major eruptions occurred within the first seven hours, and ash reached at least 45,000 feet above sea level.

In addition to the ash cloud, pyroclastic flows, fast moving hot-rock avalanches, swept into the ocean on all sides of the volcano. These flows formed deposits that extended the island's shorelines and triggered a small tsunami 19 centimeters (7.5 inches) high, as measured at the fishing community of Adak located 80 kilometers (50 miles) to the west.Kasatochi Island is about 2.4 kilometers (1.5 miles) in diameter and 314 meters (1,030 feet) high.

Before the eruption, the top of the mostly submerged volcano contained a lake-filled crater. Luckily, the eruption of Kasatochi was preceded by an unusually large earthquake sequence, including several magnitude-5 events, recorded by a seismic network located 40 kilometers (25 miles) away. These earthquakes caused the emergency evacuation of two biologists working on the volcano for the Fish and Wildlife Service less than an hour before the eruption began!

The biologists had been on the island since early summer and reported feeling earthquakes in July; they did not notice any other activity in the crater lake or flanks of the volcano until Aug. 6-7. Without a local network of monitoring instruments, AVO scientists could only locate very few earthquakes in a broad area near Kasatochi -- an area with a long history of many tectonic earthquakes -- until the larger earthquakes occurred the day before the eruption.

Clearly, had there been instruments on Kasatochi, scientists would have noticed the precursory activity in July, determined that the earthquakes were of magmatic origin beneath Kasatochi, and issued warnings several weeks before the eruption instead of one day, perhaps even before Okmok erupted on July 12.

More information can be found on AVO's Web site,
http://www.avo.alaska.eduActivity updateKilauea Volcano continues to be active. A vent in Halema'uma'u Crater is erupting elevated amounts of sulfur dioxide gas and very small amounts of ash. Resulting high concentrations of sulfur dioxide in downwind air have closed the south part of Kilauea caldera and produced occasional air quality alerts in more distant areas, such as Pahala and communities adjacent to Hawaii Volcanoes National Park, during kona wind periods.

There have been several small ash-emission events, lasting only minutes, in the last week. These are preceded by small seismic events, and are probably caused by tiny rock falls within the vent.In addition, an explosive eruption occurred from the vent in Halema'uma'u Crater at 8:13 p.m. on Sept. 2, depositing ejecta onto the crater rim, Halema'uma'u parking lot, and Crater Rim Drive. This is the sixth explosive eruption since the vent opened in March.Pu'u 'O'o continues to produce sulfur dioxide at even higher rates than the vent in Halema'uma'u Crater.

Trade winds tend to pool these emissions along the West Hawaii coast, while Kona winds blow these emissions into communities to the north, such as Mountain View, Volcano, and Hilo.Lava continues to erupt from fissure D of the July 21, 2007, eruption and flows toward the ocean through a well-established lava tube. A summit deflation/inflation cycle starting on Monday, Sept. 1, resulted in a weak ocean entry plume on Tuesday and Wednesday due to a short-term decrease in lava supply. Inflation, and the accompanying short-term increase in lava supply, commenced on Wednesday, Sept. 3, producing several small breakouts on the coastal plain on the morning of Thursday, Sept. 4.

Lava continues to flow into the ocean at Waikupanaha.Be aware that lava deltas could collapse at any time, potentially generating large explosions. This may be especially true during times of rapidly changing lava supply conditions, as have been seen lately. Do not venture onto the lava deltas. Even the intervening beaches are susceptible to large waves generated during delta collapse; avoid these beaches. In addition, steam plumes rising from ocean entries are highly acidic and laced with glass particles.

Check Civil Defense Web site (http://www.lavainfo.us) or call 961-8093 for viewing hours.Mauna Loa is not erupting. No earthquakes were located beneath the summit this past week. Continuing extension between locations spanning the summit indicates slow inflation of the volcano.Two earthquakes beneath Hawaii Island was reported felt within the past week. A magnitude-2.6 earthquake occurred at 6:33 p.m. on Sunday, Aug. 31, and was located 25 kilometers (16 miles) southwest of Waikoloa Village, at a depth of 42 kilometers (26 miles).

A magnitude-3.2 earthquake occurred at 6:54 a.m. on Monday, Sept. 1, and was located 14 kilometers (8 miles) northwest of Kailua at a depth of 8 kilometers (5 miles).Visit our Web site (hvo.wr.usgs.gov) for daily Kilauea eruption updates, a summary of volcanic events over the past year, and nearly real-time Hawaii earthquake information. Kilauea daily update summaries are also available by phone at (808) 967-8862.

Questions can be emailed to askHVO@usgs.gov.

This article was written by scientists at the U.S. Geological Survey's Hawaiian Volcano Observatory.

Saturday, September 06, 2008

Crystals can explain volcano eruptions

Scientists have exploited crystals from lavas to unravel the records of volcanic eruptions.
The team, from Durham University and the University of Leeds, studied crystal formation from a volcano, in Santorini, in Greece, to calculate the timescale between the trigger of volcanic activity and the volcano's eruption.


They say the technique can be applied to other volcanoes – such as Vesuvius, near Naples, in Italy – and will help inform the decisions of civil defense agencies.

Worldwide, it is estimated that between 50 and 70 volcanoes erupt each year, but due to the long gaps between eruptions at most volcanoes it is hard to understand how any individual volcano behaves. This work allows scientists to better understand this behavior.

The research, funded by the Natural Environment Research Council (NERC), is published this week in the prestigious scientific journal Science.

The scientists looked at crystals from the 1925-28 eruption of Nea Kameni, in Santorini.
Lead author Dr Victoria Martin, of Durham University, showed that the crystal rims reacted with molten rock, or magma, as it moved into the volcano's shallow chamber prior to eruption. This process is thought to be associated with shallow level earthquake activity, as shown by modern volcano monitoring.

By studying the area between the crystal core and the rim the team then worked out how long the rims had existed – revealing how long the magma was in the shallow chamber before it erupted.
The crystals showed the 1925-28 eruption at Nea Kameni took place three to ten weeks after the magma entered the shallow system.

As magma movement typically causes seismic activity, if any future seismic or inflation activity at Nea Kameni can be linked to magma recharge of the volcano, the scientists predict an eruption could follow within a similar timescale.

They hope this method can be applied to other volcanoes, allowing the pre-eruption behavior to be better understood - and understanding of volcanoes to be extended back further in time.
Co-author Dr Dan Morgan, from the School of Earth and Environment, at the University of Leeds, said: "We hope to develop these techniques further and apply them to more volcanoes worldwide.
"Potentially, these techniques could extend our knowledge of volcanic recharge considerably, as they can be applied to material erupted before volcanic monitoring was commonplace."

Professor Jon Davidson, Chair of Earth Sciences at Durham University, said: "We hope that what we find in the crystals in terms of timescales can be linked with phenomena such as earthquakes
"If we can relate the timescales we measure to such events we may be able to say when we could expect a volcano to erupt.

"This is an exciting new method that will help us understand the timescales of fundamental volcanic processes driving eruptions."


Historic volcano eruption

It was 125 years ago this week that one of the greatest natural disasters in the recorded history of earth occurred. The events of Aug. 26-27, 1883, were felt planet-wide for years following.To begin the account, though, we must back up a few months to the early morning of May 20, 1883. It was on that day that the captain of a German warship in the Indian Ocean reported seeing a cloud of dust and ash rising some 36,000 feet above the small Indonesian island of Krakatau.

During the next two months, numerous vessels, both commercial and chartered sightseeing ships, reported similar occurrences.And, it wasn’t just clouds. Along with the visual display came deep rumblings and explosive noises.That such geologic activity would be going on was not surprising, really. There are over 130 active volcanoes in the Indonesian island chain - the majority along the crest of the chain’s two largest islands, Java and Sumatra.

Krakatau lay in the Sunda Straits, a passage between those two islands.The island of Krakatau, as it existed then, was composed of three volcanoes run together.But that was to change.Just before 1 p.m. on Sunday, Aug. 26, 1883, a deafening, explosive blast occurred, accompanied by a roiling cloud of dense, black debris that burst from the island in a cloud that quickly rose over 80,000 feet into the air - nearly three times the height of an average thunderstorm.

Over the next few hours, that cloud would continue to rise until it reached a height of nearly 120,000 feet - or over 22 miles - into the upper stratosphere.As the day wore on, the intensity of the eruptions increased, and the villagers living in costal communities of nearby western Sumatra and Java, and other nearby islands, were battered with huge waves caused by lava flows.But that was just a taste of what was still to come.

Beginning at about 5:30 a.m. on Monday, Aug. 27, 1883, a series of at least four huge blasts preceded one unimaginable one that ripped Krakatau apart. That explosion was so massive it was heard as far away as Sri Lanka and Australia, a distance of some 3,000 miles.The force of that massive explosion plunged nearly two thirds of Krakatau - almost nine square miles in area - from a height of 1,500 feet above the level of the sea to a depth of over 800 feet beneath the waves, in an undersea crater nearly four miles across.

That blast generated massive tidal waves over 130 feet tall that inundated coastlines all along the Sunda Straits, stripping away all vegetation and washing thousands of people out to sea.

Eyewitness accounts recorded the destruction. From a passenger on board a ship that was lucky enough to survive the onslaught of the wave due to the heroic efforts of its captain, came this stark assessment: “There, where an instant before had lain the town of Telok Betong, nothing remained but the open sea.”Ash and debris from the eruption fell as far as 1,500 miles away from what once was Krakatau.

Small particles remained suspended in the upper atmosphere for years, causing spectacular sunsets and exotic colors in the sky, as well as halos around the sun and moon.Sulfur dioxide from the eruption combined with water vapor in the upper stratosphere to form acid droplets that formed a shield capable of reflecting enough sunlight to cause global temperatures to drop by several degrees.No one knows how many lost their lives in that eruption, but two weeks afterward, one traveler described what he saw this way: “Thousands of corpses of human beings and also the carcasses of animals still await burial ...

They lie in knots and entangled masses, impossible to unravel.”In 1927, a small volcano rose above the waves where Krakatau once was. It was named Anak Krakatau, or Child of Krakatoa. Since its formation, Anak Krakatau had had nearly yearly eruptions, but fortunately, none on the scale of that blast of 125 years ago this week.

Brian K. Finnicum is editor of The News Observer. He can be reached at 706-632-2019 or by e-mail at brian@thenewsobserver.com .

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