by Heather Muller , 5/9/2007
The Eureka Reporter
“I thought I was on a boat in the ocean,” said Renee Jacobsen, manager of the Petrolia Store and former chief of the remote town’s volunteer fire department.
The magnitude 5.2 earthquake that struck 39 miles west of Petrolia shortly before 1 a.m. Wednesday “pushed you up like on top of a wave,” she said.
“And then there was the aftershock,” she said, a magnitude 4.5 temblor 17 minutes later and two miles closer to shore.
“That one was more like a sharp jolt.”
According to the U.S. Geological Survey, people reported feeling the initial earthquake as far north as Trinidad and as far south as Victorville — more than 900 miles away.
Brenda Godsey, public information officer for the Humboldt County Sheriff’s Office, said her office received only one earthquake-related inquiry and no reports of injury or damage.
The Office of Emergency Services was not activated, said OES Program Coordinator Dan Larkin.
In situations like this, Larkin said, “there’s nothing we do, because there’s nothing we can do.”
Had the incident been serious, he said, any of a range of responses would have been triggered, possibly including an emergency declaration and the activation of the Emergency Alert System, as well as various local, state and federal emergency response protocols.
Humboldt State University geology professor Lori Dengler said the earthquakes were “of interest and a low level of excitement,” adding that the two events occurred along the Mendocino Fault, which is the region’s single most active fault.
“Since 1980, we’ve had about 150 earthquakes of magnitude 4 or larger along the Mendocino Fault,” she said.
Dengler described the fault as “kind of our Mason-Dixon Line. It really divides the West Coast of the United States into two completely different tectonic areas.”
To the south is the San Andreas Fault with its side-to-side “transform” movement. To the north are the Gorda and the Juan de Fuca plates that converge along the coast and dive down to create the vertical movement characteristic of the Cascadia Subduction Zone.
The Mendocino Fault itself, where Wednesday’s earthquakes occurred, moves horizontally, Dengler said.
“So if you had been standing south of the Mendocino Fault, and if there were no water in the ocean and you could have actually seen what was going on, you would have seen the land north of the fault move maybe half a foot closer to the coast,” she said.
But it could have been worse.
“In the 1906 earthquake, had you been on the San Andreas Fault and looked across to the other side, you would have seen it move more than 20 feet in some places,” she said.
Dengler has long said the North Coast is overdue for a damaging earthquake.
“The point I really like to make is that this is the time to take action to reduce your hazards. It can be something as simple as that huge potted plant on a bookshelf above your bed. Maybe there’s a better place for it. Develop an emergency plan for your family. Make sure your hot water heater is secured to a structural element of your house.
“They’re small things, but they can make a big difference.”
On shaky ground: Significant North Coast earthquakes of the past 30 years
+ June 14, 2005 6:50 p.m.
Magnitude 7.2, centered 97 miles west of Trinidad
Felt lightly but resulted in tsunami warning for the entire West Coast
No reports of injury or damage
+ Feb. 18, 1995 8:03 p.m.
Estimated magnitude 6.5, centered 80 miles west-southwest of Eureka
No reports of injury or significant damage
+ Dec 26, 1994 6:10 a.m.
The Eureka Earthquake
Estimated magnitude 5.4, centered 12 miles west-southwest of Eureka
Minor injuries reported and damages estimated at more than $2.3 million
+ Sept. 1, 1994 8:15 a.m.
The Mendocino Fault Earthquake
Estimated magnitude 6.9, centered approximately 90 miles west of Cape Mendocino
No reports of injury or significant damage
+ April 25, 1992 11:06 a.m.
The Ferndale Earthquake
Magnitude 7.1, centered near Petrolia
Followed by aftershocks of magnitude 6.6 and 6.7 near Cape Mendocino
Damage estimated at $60 million, resulted in federal disaster declaration
+ Sept. 17, 1991 12:29 p.m.
The Honeydew Earthquake
Estimated magnitude 6.1, centered 13 miles south-southeast of Cape Mendocino
More than 60 percent of Honeydew residents reported structural damage
+ Nov. 8, 1980 2:27 a.m.
The Trinidad Earthquake
Magnitude 7.1, centered 30 miles west of Trinidad
Freeway overpass south of Eureka collapsed
Regional damages estimated at $1.75 million
Source: Humboldt State University Geology Department’s Humboldt Earthquake Education Center
On April 24, 1984 at 1:15 p.m. PST, a 6.2 magnitude earthquake occurred on the Calaveras fault to the east of San Jose, California. This earthquake was felt over an area of approximately 120,000 km2 in California and western Nevada. The area of moderate damage ($8 million) extended southward from the epicenter rather than centering on the epicenter. This pattern indicates that the Morgan Hill earthquake may have been a double event with the second event being located about 17 km southeast of the main shock.
In Santa Clara County, where most of the damage occurred, more than 550 structures incurred minor damage. Major structural damage was mainly confined to a very small area on two streets of the Jackson Oaks subdivision located east of Morgan Hill (population 19,000). Five houses were condemned; two of these had fallen off their concrete foundations and suffered partial collapse. Several masonry buildings on Main Street in Morgan Hill were damaged and later condemned. Well-engineered industrial buildings and residential structures sustained only minor damage, but many mobile homes fell off their supports causing considerable damage to the furnishings inside. There were many reports of fires resulting from the quake. Minor damage also occurred at San Martin and Coyote. Twenty-seven people were injured.
In Santa Clara County, where most of the damage occurred, more than 550 structures incurred minor damage. Major structural damage was mainly confined to a very small area on two streets of the Jackson Oaks subdivision located east of Morgan Hill (population 19,000). Five houses were condemned; two of these had fallen off their concrete foundations and suffered partial collapse. Several masonry buildings on Main Street in Morgan Hill were damaged and later condemned. Well-engineered industrial buildings and residential structures sustained only minor damage, but many mobile homes fell off their supports causing considerable damage to the furnishings inside. There were many reports of fires resulting from the quake. Minor damage also occurred at San Martin and Coyote. Twenty-seven people were injured.
Associated Press - Petrolia, CA (April 6, 2007)
A small quake struck off the coast of Humboldt County on Thursday afternoon (4/5/07), but there were no immediate reports of injuries or damages.
The magnitude-4.1 earthquake struck at 3:54 p.m. and was centered about 40 miles southwest of Eureka and 206 miles northwest of Sacramento, according to the U.S. Geological Survey
There were no immediate reports of damage or injuries, according to a spokeswoman for the Humboldt County Sheriff's Department.
A small quake struck off the coast of Humboldt County on Thursday afternoon (4/5/07), but there were no immediate reports of injuries or damages.
The magnitude-4.1 earthquake struck at 3:54 p.m. and was centered about 40 miles southwest of Eureka and 206 miles northwest of Sacramento, according to the U.S. Geological Survey
There were no immediate reports of damage or injuries, according to a spokeswoman for the Humboldt County Sheriff's Department.
From the CNN
"At least six people died in the Solomon Islands Monday after two earthquakes and a tsunami hit the western part of the island-chain nation, the country's chief spokesman said.....The United States Geological Survey said the first earthquake took place at 6:40 a.m. (2040 GMT on Sunday) and was centered 25 miles south-southeast of Gizo, New Georgia Islands, and 1,330 miles north-northeast of Brisbane, Australia.A second quake of 6.7 magnitude hit a few minutes later, according to the USGS. It was centered 75 miles west-southwest of Chirovanga, Choiseul, Solomon Islands, and 1,410 miles north of Brisbane, Australia.
The quakes led to a tsunami warning for a huge part of the Pacific. Australia and Indonesia were among the areas named in a warning from the Pacific Tsunami Warning Center, as were Papua New Guinea and several other islands in the region.A watch was issued for some other parts of the Pacific, including New Zealand, the Philippines, American Samoa, Guam and Fiji.
Initially, Hawaii was put under an advisory, but not a watch or warning. By evening, the advisory was lifted. The Solomon Islands are popular with international tourists. Most homes in the mountainous islands are constructed of timber and bamboo, with villagers relying on fishing and logging for employment."
hi
pl watch folloeing dates for major earthquakes of more han 7.5 magnitude
8th, 24/25th april,28 th april 2007
2/3 rd and 10th May 2007
16th june 2007
13/14 th and 22nd August 2007
22 and 29th Dec 2007
pl watch these dates
regards
A.J.DAVE
pl watch folloeing dates for major earthquakes of more han 7.5 magnitude
8th, 24/25th april,28 th april 2007
2/3 rd and 10th May 2007
16th june 2007
13/14 th and 22nd August 2007
22 and 29th Dec 2007
pl watch these dates
regards
A.J.DAVE
A powerful earthquake has struck the Indonesian island of Sumatra, killing at least 70 people and flattening hundreds of buildings. The US Geological Survey said the quake had a magnitude of 6.3, and was centred near the town of Padang.
There are fears the death toll may be higher as many people are believed to have been trapped beneath rubble. The quake struck at 1049 local time (0349 GMT), causing panic among residents in western Sumatra.
A strong aftershock - magnitude 6.0 according to the US Geological Survey - struck two hours later causing further damage and panic.
An Indonesian government spokesman, Sudi Silalahi said 70 people had been killed.
Read BBC News for the full story.
There are fears the death toll may be higher as many people are believed to have been trapped beneath rubble. The quake struck at 1049 local time (0349 GMT), causing panic among residents in western Sumatra.
A strong aftershock - magnitude 6.0 according to the US Geological Survey - struck two hours later causing further damage and panic.
An Indonesian government spokesman, Sudi Silalahi said 70 people had been killed.
Read BBC News for the full story.
SIR
pl find herewith my theory of earthquake prediction and the dates for probable earthquakes in the year 2007.
A.J.DAVE
amitjdave@yahoo.com
pl find herewith my theory of earthquake prediction and the dates for probable earthquakes in the year 2007.
A.J.DAVE
amitjdave@yahoo.com
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