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Volcano Watch: Kilauea Update for March 22, 2012

(Activity update written by scientists at the U.S. Geological Survey’s Hawaiian Volcano Observatory.)

A lava lake present within the Halema’uma’u Overlook vent during the past week resulted in night-time glow that was visible from the Jaggar Museum overlook. The lake, which is normally about 90–115 m (295–377 ft) below the floor of Halema’uma’u Crater and visible by HVO`s Webcam, rose and fell slightly during the week in response to a series of large deflation-inflation cycles.

On Kilauea’s east rift zone, surface lava flows were active on the pali and upper coastal plain, in Royal Gardens subdivision, over the past week. As of Thursday, March 22, the flows were still more than 2 km (1.2 miles) from the coast, and there was no active ocean entry.

Two earthquakes beneath Hawai’i Island were reported felt this past week. A magnitude-2.7 earthquake occurred at 3:42 p.m., HST, on Monday, March 19, 2012, and was located 4 km (2 mi) southeast of Pu’ulena Crater at a depth of 2 km (1 mi). A magnitude-3.7 earthquake occurred at 00:04 a.m. (4 minutes after midnight) on Thursday, March 22, and was located 40 km (25 mi) west and offshore of Kailua-Kona at a depth of 33 km (21 miles).

…(Hawaii 24-7)

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March 23, 2012 Posted by | Seismic, Volcanic | , , , , , , , | Leave a comment

USGS reports quake near Wisconsin city plagued by booming sounds

People turn out to get their questions answered at a meeting with city officials about the mysterious booming and rumbling in Clintonville, Wis., Wednesday, March 21, 2012.

A minor earthquake occurred this week near the eastern Wisconsin city where researchers have been investigating a series of unexplained booming sounds, federal geologists said Thursday.

The U.S. Geological Survey said the 1.5-magnitude earthquake struck Tuesday just after midnight in Clintonville, a town of about 4,600 people about 40 miles west of Green Bay.

Geophysicist Paul Caruso told The Associated Press that loud booming noises have been known to accompany earthquakes. It’s possible the mysterious sounds that town officials have been investigating are linked to the quake, he said.

Earthquakes can generate seismic energy that moves through rock at thousands of miles per hour, producing a sonic boom when the waves come to the surface, Caruso said.

“To be honest, I’m skeptical that there’d be a sound report associated with such a small earthquake, but it’s possible,” he said.

Those reservations didn’t stop Clintonville City Administrator Lisa Kuss from declaring “the mystery is solved” at a news conference Thursday evening.

She said USGS representatives described the event as a swarm of several small earthquakes in a very short time.

“In other places in the United States, a 1.5 earthquake would not be felt,” she said. “But the type of rock Wisconsin has transmits seismic energy very well.”

The U.S. Geological Survey says earthquakes with magnitude of 2.0 or less aren’t commonly felt by people and are generally recorded only on local seismographs. Caruso said the Tuesday earthquake was discovered after people reported feeling something, and geologists pored through their data to determine that an earthquake did indeed strike.

Local residents have reported late-night disturbances since Sunday, including a shaking ground and loud booms that sound like thunder or fireworks.

City officials investigated and ruled out a number of human-related explanations, such as construction, traffic, military exercises and underground work.

Clintonville resident Jordan Pfeiler, 21, said she doubted an earthquake caused the noises. She said the booms she experienced were in a series over the course of several hours and not continuous as she might have expected if they were caused by an earthquake.

Still, she said, “It’s a little scary knowing Clintonville could even have earthquakes.”

Steve Dutch, a geologist at the University of Wisconsin-Green Bay, said a 1.5 magnitude earthquake produces the energy equivalent of 100 pounds of explosives and could produce loud sounds.

…(Washington Post)

March 23, 2012 Posted by | Seismic | , , , , , , , , | Leave a comment

5.9 Magnitude Earthquake Rattles Taiwan

A shallow 5.9-magnitude earthquake sent people fleeing onto the streets in Taiwan’s second-largest city of Kaohsiung and led to temporary halting of rail services. No casualties were reported yesterday.

The quake struck 57 kilometers east of the southern city at 10.34am at a depth of just four kilometers, the US Geological Survey said. The Hong Kong Observatory measured the quake at a magnitude of six, while Taiwan’s Seismology Centre put it at 6.1. The National Fire Agency said there were no casualties or major material damage.

“A few Kaohsiung residents sought safety in the streets for a short while, but it wasn’t many,” a police officer said.

A spokesman for the center said it is relatively rare for a quake of such magnitude to hit the Kaohsiung area. “While the quake was strong, it didn’t last long,” Chen Jung-yu said.

“Even in some towns near the epicenter, buildings swayed for no more than seven seconds. That explained why it did not inflict damages.”

A high-speed railway linking Kaohsiung with Taipei in the north resumed about 90 minutes after the quake prompted services to be suspended. The greater metropolitan area of Kaohsiung has a population of nearly three million.

Taiwan is regularly hit by quakes as it lies near the junction of two tectonic plates.

In September 1999, a 7.6-magnitude tremor killed 2,400 people in the deadliest natural disaster in the island’s recent history.

…(The Standard)

February 27, 2012 Posted by | Seismic | , , , , , | Leave a comment

6.0 Magnitude EQ – Off the Coast of Oregon

A strong 6.0 magnitude earthquake struck on Tuesday roughly 160 miles off the coast of Oregon, the U.S. Geological Survey said. This earthquake comes one day after a 5.6 magnitude quake rattled Northern California near the Pacific Coast.

A 4.2 magnitude earthquake struck off the coast of Vancouver Island toward the northern edge of the Juan de Fuca plate earlier in the day on February 14 at 2:54 p.m. local time.

With all quakes, being prepared and having a plan is the only true defense as a quake can happen at any time.

At approximately 03:31:20 UTC on Wednesday, February 15th, the 6.0 magnitude earthquake based on water struck at a depth of 10.0 km (6.2 miles) off the coast of Oregon, 256 km (159 miles) W of Coos Bay, Oregon. Coords: 43.536°N, 127.381°W

…(USGS)

The 1700 Cascadia earthquake was a magnitude 8.7 to 9.2 megathrust earthquake that occurred in the Cascadia subduction zone on January 26, 1700. The earthquake involved the Juan de Fuca Plate underlying the Pacific Ocean, from mid-Vancouver Island in British Columbia, Canada, south along the Pacific Northwest coast as far as northern California, USA.

The length of the fault rupture was about 1,000 kilometers (620 miles) with an average slip of 20 meters (22 yards).

The earthquake caused a tsunami that struck the coast of Japan, and may also be linked to the Bonneville Slide.

February 15, 2012 Posted by | Seismic | , , , , , | 1 Comment

6.5 Magnitude EQ – Solomon Islands, 6.0 EQ – Near the East Coast of Honshu

At approximately 08:19:58 UTC on Tuesday, February 14th, a 6.5 magnitude earthquake based on water struck at a depth of 54.7 km (34.0 miles) in the region of the Solomon Islands, 72 km (44 miles) W of Kira Kira, Solomon Islands. Coords: 10.387°S, 161.262°E

…(USGS)

As well, a 6.0 Magnitude EQ struck near the East Coast of Honshu at 06:21:58, 93 km (57 miles) ESE of Mito, Honshu, Japan, at a depth of 10km (6.2 miles)… (USGS)

A powerful earthquake rocked eastern Japan Tuesday, but no tsunami warning was issued and no damage was reported at the crippled Fukushima nuclear plant.

The US Geological Survey said the 6.0 magnitude quake, with an epicentre 10 kilometres (six miles) deep, was centred 166 kilometres east-northeast of Tokyo, where correspondents said buildings swayed.

Japan’s meteorological agency also located the quake off the coast of Ibaraki prefecture, south of the stricken plant. A very small change of tidal level was forecast but was not expected to cause any damage. Nuclear plant operator Tokyo Electric Power Co. (TEPCO) said the stricken Fukushima Daiichi plant remained stable.

…(Vancouver Sun)

February 14, 2012 Posted by | Seismic | , , , , , , , , | Leave a comment

5.6 Magnitude EQ – Northern California

A moderate earthquake struck Northern California’s coast Monday afternoon, rattling nerves around the Oregon border but yielding no immediate reports of major injuries or damage.

The magnitude-5.6 quake struck at 1:07 p.m. about 18 miles (30 kilometers) east of Trinidad, in an unincorporated part of Humboldt County, the U.S. Geological Survey said. The epicenter was a rural area near the small community of Weitchpec on the Hoopa Valley Indian Reservation, about 240 miles (350 kilometers) north of San Francisco and about 60 miles (96 kilometers) south of the Oregon border.

The temblor was widely felt within a 100-mile (160-kilometer) radius, but the National Oceanic and Atmospheric Administration said it wasn’t large enough to generate a tsunami.

The Humboldt County Sheriff’s Department and Eureka Police Department sent deputies and officers to check on residents, but dispatchers said there were no immediate reports of emergencies. Things also seemed fine on the Hoopa reservation, according to Byron Nelson Jr., the tribe’s vice chairman.

“It was just a mild shaking. It wasn’t a sharp jerk,” said Sgt. Gene McManus of the Del Norte County Sheriff’s Department, a neighboring agency that also saw no immediate problems.

On January 9, 2010, a 6.5 earthquake 25 miles southwest of Eureka ‘snapped power lines’. The last major earthquake, a magnitude 7.2 on April 25, 1992, which triggered a small tsunami. Eureka is located near the Mendocino Triple Junction Region, “one of the most seismically active regions of the San Andreas transform system”.

…(Associated Press)

At approximately 21:07:02 UTC on Monday, February 13th, an earthquake based on land struck at a fairly shallow depth of 32.9 km (20.4 miles) in the region of Northern California, 10 km (6 miles) WSW of Weitchpec, CA, and 29 km (18 miles) ENE of Trinidad, CA. Coords: 41.153°N, 123.817°W

Initially reported by the USGS as a 5.3, then upgraded to a 5.5, and then 5.6.

…(USGS)

February 14, 2012 Posted by | Seismic | , , , , , | Leave a comment

Magnitude 6.7 Earthquake Kills 43 in the Cebu region of the Philippines

At approximately 03:49:17 UTC on Thursday, February 6th, an earthquake based on water struck at a depth of 20 km (24.4 miles) in the Cebu region, Philippines, 72 km (44 miles) N of Dumaguete, Negros, Philippines, and 74 km (45 miles) WNW of Tagbilaran, Bohol, Philippines. Coords: 9.964°N, 123.246°E

The earthquake was followed by a number of aftershocks, the largest being a 4.8, 5.6, 6.0, 5.8 and a 5.2 following within 8 hours after the initial quake.

United States Geological Survey – The main event has been reviewed by a seismologist and confirmed, at present, to be a 6.7 magnitude earthquake at a depth of 20 km (24.4 miles). The European Mediterranean Seismology Agency is in agreeance with the main earthquake parameters provided by the USGS.

…(USGS) (EMSC)

Filipino officials say a strong earthquake has rocked the central Philippines, killing at least 43 people and causing widespread damage and power outages.

The U.S. Geological Survey says the 6.8-magnitude quake struck late Monday morning at a depth of 20 kilometers. The quake was centered in a narrow strait just off Negros Island. Authorities say a landslide killed 29 people, others were killed in buildings and homes that collapsed on Negros, including the seaside town of La Libertad. Dozens of people are missing.

Numerous aftershocks continued to shake the island hours after the quake.

Officials say there is no concern of a tsunami, although some coastal towns nearby were hit by large waves.

…(Voice of America)

February 7, 2012 Posted by | Seismic | , , , , , , | Leave a comment

Concerns Grow over Volcanic Eruptions

Scientists have known for decades that hidden under those impressive vistas at sites such as Death Valley and Yellowstone National Park are magma pools that under the right conditions can trigger explosive eruptions.

Now, new research is changing scientists’ understanding of the timing of those eruptions, and prompting them to call for greater monitoring of sites to help save lives when the next big volcano explodes.

Two recent papers highlight the shift. One looked at a Death Valley volcano thought to be 10,000 years old and found it last erupted just 800 years ago, and is still an eruption danger. The other found that large caldera volcanoes, such as the one under Crater Lake in Oregon, can recharge in a matter of decades, rather than the thousands of years previously thought.

“The understanding of the timing of eruptions and the timing of the building up to eruptions is changing,” says Margaret Mangan, the scientist in charge of volcano monitoring in California for the U.S. Geological Survey. “These two papers are very nice examples of good scientific work.”

One thing that’s coming to light is that eruptions are often clustered, with “long stretches of inactivity punctuated by periods of activity that can go on for years,” Mangan says.

The first paper looked at the Ubehebe Crater (you-bee-HE-bee) at the northern end of California’s Death Valley. It’s about half a mile wide and 700 feet deep. It was long believed to have been caused by a volcanic eruption sometime in the past 10,000 years or so.

However, researchers recently looked at beryllium in the rocks and were able to date the last series of eruptions to just 800 years ago. They say the ingredients necessary for another eruption are all still there.

Ubehebe Crater is the result of what’s known as a phreatomagmatic (free-at-oh-mag-MAT-ick) eruption. That means that it has a huge pocket of molten rock, or magma, deep below it. When it begins to push to the surface and comes into contact with water, superhot steam is created, building up pressure until it explodes.

It had been thought that the eruptions would occur only during wet climate periods, and as Death Valley is famously dry now, there was little concern. But using U.S. Geological Survey data, the scientists show that the current water table may be just 500 feet below the surface of the crater.

Caldera volcanoes consist of large underground lakes of magma. As more magma builds up, the pressure builds and the magma starts getting pushed upward through cracks in the Earth’s surface. When the pressure gets too great, it explodes.

Caldera volcanoes typically have a long quiet period prior to eruptions. Writing in Wednesday’s edition of the journal Nature, researchers looked at the eruption of the Santorini volcano in Greece around 1,600 B.C., which released as much as 12 cubic miles of magma.

…(USA Today)

February 3, 2012 Posted by | Volcanic | , , , , , | Leave a comment

Series of Large Earthquakes Strike Vanuatu

At approximately 13:34:41 UTC on Thursday, February 2nd, an earthquake based on water struck at a depth of 23.1 km (14.4 miles) in the Vanuatu region, 124 km (77 miles) W of Port-Vila, Efate, Vanuatu, and 251 km (155 miles) S of Luganville, Espiritu Santo, Vanuatu. Coords: 17.766°S, 167.134°E

The largest recorded initial quake was a 4.8 magnitude at approximately 10:44:08 UTC, at a depth of 147.2 km (91.5 miles). Following the 7.1 a series of large aftershocks began and still continue to be recorded in the area. After the 7.1 struck, a 4.9 and 5.3 hit the area within 25 minutes, and from 16:00 to 22:00, a 5.0, 5.5, 5.2, 4.9, 5.1, 5.1 and 4.8 also hit the area. On February 3rd, at approximately 03:46:23, a 6.0 magnitude aftershock it appears, struck the area as well, at a depth of 21.7 km (13.5 miles), followed by a 5.4 at 04:33:09 and a 5.7 quake at 06:01:42.

United States Geological Survey – The main event has been reviewed by a seismologist and confirmed, at present, to be a 7.1 magnitude earthquake at a depth of 23.1 km (14.4 miles). The European Mediterranean Seismology Agency is in agreeance with the main earthquake parameters provided by the USGS, except for depth, which is recorded to have been at 10 km.

Based on all available data a destructive Pacific-wide tsunami is not expected and there is no tsunami threat for Hawaii

…(USGS) (EMSC) (PTWC)

The region of Vanuatu is on the so-called Pacific Ring of Fire, an arc of unstable fault lines circling the Pacific Basin that is prone to frequent and large earthquakes. In August of 2011, two powerful earthquakes measuring 7.1 and 7.4 mag on the Richter scale struck about 63 kilometers south-southwest of Port-Vila, on the south coast of the island of Efate.

February 3, 2012 Posted by | Seismic | , , , , | 1 Comment

The USGS Monitors Earth’s Magnetic Field to Prepare for Magnetic Storms

Everyone is familiar with weather systems on Earth like rain, wind and snow. But space weather – variable conditions in the space surrounding Earth – has important consequences for our lives inside Earth’s atmosphere.

Solar activity occurring miles outside Earth’s atmosphere, for example, can trigger magnetic storms on Earth. These storms are visually stunning, but they can set our modern infrastructure spinning.

On Jan. 19, scientists saw a solar flare in an active region of the Sun, along with a concentrated blast of solar-wind plasma and magnetic field lines known as a coronal mass ejection that burst from the Sun’s surface and appeared to be headed for Earth. When these solar winds met Earth’s magnetic field, the interaction created one of the largest magnetic storms on Earth recorded in the past few years. The storm peaked on Jan. 24, just as another storm began.

“These new storms, and the storm we witnessed on Sept 26, 2011, indicate the up-tick in activity coming with the Earth’s ascent into the next solar maximum,” said USGS geophysicist Jeffrey Love.” This solar maximum is the period of greatest activity in the solar cycle of the Sun, and it is predicted to occur sometime in 2013, which will increase the amount of magnetic storms on Earth.

Magnetic storms, said Love, are a space weather phenomenon responsible for the breathtaking lights of the aurora borealis, but also sometimes for the disruption of technology and infrastructure our modern society depends on. Large magnetic storms, for example, can interrupt radio communication, interfere with global-positioning systems, disrupt oil and gas well drilling, damage satellites and affect their operations, and even cause electrical blackouts by inducing voltage surges in electric power grids.

Storms can also affects airline activity — as a result of last weekend’s  storm, both Air Canada and Delta Air Lines rerouted flights over the Arctic bound for Asia as a precautionary measure. Although the storm began on the 19th of January, it did not peak until January 24th.

…(USGS)

January 31, 2012 Posted by | Solar, Space | , , , , , | Leave a comment