Wikipedia - Benutzerbeiträge [de]

Northridge-Erdbeben 1994

2008-10-03T05:23:44Z

MacsBug: /* Damage and fatalities */ Fixed typo

{{earthquake
|title= Northridge earthquake
|image=Northridge earthquake 10 frwy2.png
|caption=The underpass of the I-10 Freeway at La Cienega Blvd. This image shows the collapsed section of the freeway.
|map=
|date=[[January 17]] [[1994]]
|magnitude=6.7 [[Moment magnitude scale|Mw]]
|depth= 17.0 [[kilometers|km]]
|epicenter location={{coord|34|12|47|N|118|32|13|W|}}
|countries affected=[[United States]] ([[Southern California]])
|location=[[Reseda, Los Angeles, California|Reseda, California]]
|intensity = [[Mercalli intensity scale|IX - Ruinous]]
|casualties=72 killed over 12,000 injured
}}

The '''Northridge earthquake''' occurred on [[January 17]] [[1994]] at 4:31 AM [[Time zone|Pacific Standard Time]] in [[Reseda, Los Angeles, California|Reseda]], a neighborhood in the city of [[Los Angeles, California]]. The [[earthquake]] had a "strong" [[moment magnitude]] of 6.7, but the [[Peak ground acceleration|ground acceleration]] was the highest ever instrumentally recorded in an urban area in North America.<ref>[http://www.data.scec.org/chrono_index/northreq.html Northridge Earthquake] Southern California Earthquake Data Center, Accessed [[October 6]] [[2006]]</ref> Seventy-two people died as a result of the earthquake with more than 12,000 injured. In addition, the earthquake caused an estimated $12.5 billion in damage, making it one of the costliest natural disasters in U.S. history.<ref name=">{{cite web| title = Anniversary of Deadly Northridge Quake|publisher=abc7.com|date=|url= http://abclocal.go.com/kabc/story?section=local&id=3819852|accessdate=2007-07-08 }}</ref>

==The earthquake==
The earthquake struck in the [[San Fernando Valley]] about 20 miles (31 km) northwest of downtown Los Angeles near the community of [[Northridge, Los Angeles, California|Northridge]]. The actual epicenter of the quake was in Reseda, near the intersection of Reseda Blvd. and Saticoy St. However, it took several days to pinpoint the epicenter with accuracy, and in the meantime the media had already dubbed it "The Northridge Earthquake." The name stuck, in part due to the extensive damage and loss of life in Northridge. The [[National Geophysical Data Center]] places the epicenter's geographical coordinates at {{coord|34|12|47|N|118|32|13|W|}} and a depth of 17 km (10.56mi). Despite the area's proximity to the [[San Andreas Fault]], the Northridge quake did not occur along this fault, but rather on a previously-undiscovered [[Thrust fault|blind thrust fault]].

===Damage and fatalities===
[[Image:Northridge earthquake 10 frwy3.png|thumb|300px|The freeway "bent" just before the section collapsed]]
[[Image:Kaiser Permanente Building After Northridge Earthquake.jpg|thumb|300px|Kaiser Permanente building]]
[[Image:Collapsed Apartment After Northridge Earthquake.jpg|thumb|300px|Collapsed apartment building]]
[[Image:Street Damage After Northridge Earthquake.jpg|thumb|300px|Street damage]]
Damage occurred up to 85 miles (125 km) away, with the most damage in the west [[San Fernando Valley]], and the cities of [[Santa Monica, California|Santa Monica]], [[Simi Valley, California|Simi Valley]] and [[Santa Clarita, California|Santa Clarita]]. Fifty-seven people died as a result of the earthquake, and more than 7,000 were injured including 1,600 that required hospitalization.<ref>[http://www.huduser.org/publications/destech/bigone/summary.html Executive Summary]</ref> Major freeway damage occurred up to 32 km (20 mi) from the epicenter. Portions of [[Interstate 10 (California)|Interstate 10]] (the [[Santa Monica Freeway]]), [[Interstate 5 (California)|Interstate 5]] (the [[Golden State Freeway]]) and [[California State Route 14|State Route 14]] (the [[Antelope Valley Freeway]]) collapsed and had to be rebuilt. The [[Newhall Pass interchange]] of [[Interstate 5 (California)|Interstate 5]] and [[California State Route 14|State Route 14]] collapsed as it had 23 years earlier during the 1971 [[Sylmar earthquake]] even though it had been rebuilt with improved structural components.<ref>[http://www.tfhrc.gov/pubrds/summer94/p94su26.htm Public Roads On-Line (Summer 1994): The Northridge Earthquake: Progress Made, Lessons learned in Seismic-Resistant bridge Design]</ref> One life was lost in the Newhall Pass interchange collapse: [[LAPD]] motorcycle officer Clarence W. Dean fell 40 feet from the damaged connector from southbound 14 to southbound I-5 along with his motorcycle. Because of the early morning darkness, he was unaware that the elevated roadway beneath him had dropped, and was unable to stop in time to avoid the fall and died instantly. When the interchange was rebuilt again one year later, it was renamed the Clarence Wayne Dean Memorial Interchange in his honor.

Additional damage occurred about 50 miles south in [[Anaheim, California|Anaheim]] as the scoreboard at Anaheim Stadium collapsed onto several hundred seats. Fortunately, the stadium was empty at the time of the quake due to the time of day the earthquake occurred. Although several commercial buildings also collapsed, loss of life was minimized because of the early morning hour of the quake, and it occurred on a Federal holiday ([[Martin Luther King, Jr. Day]]). Also, because of known seismic activity in California, area [[building code]]s dictate that buildings incorporate [[structural design]] intended to withstand earthquakes. However, the damage caused by the earthquake revealed that some structural specifications did not perform as well as expected. Because of this building codes were revised. Some structures were not [[Red-tagged structure|red-tagged]] until months after the earthquake because damage was not immediately apparent.

The quake produced unusually strong ground accelerations in the range of 1.0 [[g-force|''g'']]. Damage was also caused by fire and landslides. The Northridge earthquake was notable for striking almost the same area as the MW 6.6 [[San Fernando Earthquake|San Fernando (Sylmar) Earthquake]]. In terms of property damage, the earthquake is one of the worst [[natural disaster]]s in U.S. history.{{Fact|date=February 2007}}. Some estimates of total damage range as high as $25 billion.

Most casualties and damage occurred in multi-story wood frame buildings (e.g. the three-story Northridge Meadows apartment building). In particular, buildings with a weak first floor (such as those with parking areas on the bottom) performed poorly. Numerous fires were also caused by broken gas pipes caused by houses shifting off foundations or by unsecured water heaters falling over.<ref>[http://www.earthquakecountry.info/daretoprepare/stuff/waterheater.html Secure Your Stuff: Water Heater]</ref> In the San Fernando Valley, several underground gas and water mains were severed, and there were some streets where there were fires burning through floods. As is common in earthquakes, [[unreinforced masonry building]]s and houses on steep slopes suffered damage. However, school buildings (K-12), which are required to be reinforced against earthquakes, in general survived fairly well.

===Base isolation===
Before the Northridge earthquake occurrence, a heavy [[damping]] mechanism sometimes incorporated in [[vibration control]] technologies and, particularly, in '''base isolation''' devices was considered a valuable source of suppressing vibrations thus enhancing a building's [[seismic performance]]. However, for the very pliant systems such as '''base isolated''' [[structures]], with a relatively low bearing [[stiffness]] but with a high [[damping]], the so-called "damping force" turned out the main pushing force at this strong earthquake [http://www.ecs.csun.edu/~shustov/Topic2.htm]. The finding created a theoretical ground in [[earthquake engineering]] for a damping-disengaged '''base isolation''' technology called [[Earthquake Protector]] [http://www.youtube.com/watch?v=kzVvd4Dk6sw].

===Valley Fever===
An unusual effect of the Northridge earthquake was an outbreak of [[coccidioidomycosis]] (Valley Fever), a respiratory disease caused by inhaling airborne spores. The number of cases (203) in [[Ventura County, California|Ventura County]] was roughly 10 times the normal rate in the eight weeks following the earthquake and three people died. It is thought that the spores were carried in large clouds of dust created by seismically triggered landslides. Most of the cases occurred immediately downwind of the landslides.<ref>[http://landslides.usgs.gov/recent/archives/1997northridge.php Coccidioidmycosis Outbreak]</ref>

===Hospitals===
Eleven hospitals suffered structural damage and were damaged or unusable after the earthquake.<ref>[http://www.huduser.org/publications/destech/bigone/summary.html Executive Summary]</ref> Not only were they unable to serve their local neighborhoods, they had to transfer out their inpatient populations, which further increased the burden on nearby hospitals that were still operational. As a result, the state legislature passed a law requiring all California hospitals to ensure that their acute care units and emergency rooms are in earthquake-proof structures by [[January 1]] [[2005]].

===Television production stoppages===
The quake stopped production of movies and TV shows filming in the area at the time, most notably ''[[The Simpsons]]'' season 6's first two episodes "[[Bart of Darkness]]" and "[[Lisa's Rival]]".

===Changes===
The Northridge earthquake led to a number of legislative changes. Due to the large amount lost by insurance companies because of the earthquake, most insurance companies either stopped offering or severely restricted earthquake insurance in California (and elsewhere). In response, the California Legislature created the [[California Earthquake Authority]] (CEA), which is a publicly managed but privately funded organization that offers minimal coverage.<ref>[http://www.earthquakeauthority.com/ California Earthquake Authority (CEA) Version 2.0]</ref> A substantial effort was also made to reinforce freeway bridges against seismic shaking and a law requiring water heaters to be properly strapped was passed in 1995.

==Notes==
{{reflist|1}}

==External links==
*[http://www.data.scec.org/chrono_index/northreq.html Southern California Earthquake Data Center]
*[http://pasadena.wr.usgs.gov/office/hudnut/hudnut/nr_eq.html USGS Pasadena]
*[http://www.usc.edu/dept/civil_eng/Earthquake_eng/North_res/ USC Earthquake Engineering-Strong Motion Group]
*[http://www.sacsteel.org/ SAC Steel Project (Study of welded steel failures)]

{{DEFAULTSORT:Northridge earthquake, 1994}}
[[Category:1994 natural disasters]]
[[Category:Earthquakes in California]]
[[Category:History of Los Angeles, California]]
[[Category:History of the United States (1991–present)]]
[[Category:San Fernando Valley]]
[[Category:1994 earthquakes]]

[[af:Northridge-aardbewing]]
[[es:Terremoto de Northridge de 1994]]
[[ja:ノースリッジ地震]]
{{Significant earthquakes in California}}

Northridge-Erdbeben 1994

2008-10-03T05:23:44Z

MacsBug: /* Damage and fatalities */ Fixed typo

Angriffe auf Nordamerika während des Zweiten Weltkriegs

2005-09-30T17:15:18Z

MacsBug: Fixed spelling errors

'''Attacks on America during WWII''' by Axis forces were made more than once.

The [[attack on Pearl Harbor]] on the morning of December 7, 1941 was the first of such assaults.

The Philippines (at the time an American territory) were captured as were other American Islands in the Pacific in late 1941 and early 1942.

On [[February 23]], [[1942]] a Japanese I-17 submarine commanded by Captain Nishino Kozo shelled the Ellwood oil facilities near [[Goleta, California|Goleta]] located up the beach from [[Santa Barbara, California|Santa Barbara]].

Nishino reported by radio to Tokyo that he had left Santa Barbara in flames, even though only a catwalk and a pumphouse were damaged. Total damage from the shelling was estimated to be approximately $500. Many of the shells fired by the submarine landed miles inland, in the chaparral-covered hills behind the oil production facilities.

After the war it was discovered that Nishino had visited the Ellwood oil facilities in the 1930's as a skipper on an oil tanker. Apparently he stumbled into a field of [[prickly pear cactus]]. One theory to explain why he chose Ellwood as a target was that Captain Nishino never forgave the ridicule he received from his American hosts that day, and came back seeking revenge. Nishino was killed in August 1942 when his submarine was sunk off of [[New Caledonia]].

On the night of 24th and 25th in February of 1942 there an incident remembered as [[The Battle for Los Angeles]]. [http://www.militarymuseum.org/BattleofLA.html]

On the night of June 21st 1942 a Japanese submarine surfaced near the Columbia River in Oregon, and fired shells at nearby [[Fort Stevens]] damaging only a baseball backstop. This was the only American mainland military installation attacked during WWII.

In July of 1942 the Aleutian islands were invaded by Japanese forces to divert American forces away from the main Japanese attack at Midway Atoll. The United States, having broken the Japanese military codes, knew that this was a diversion and did not expend large amounts of effort defending the islands. Some Americans were taken to Japan as prisoners of war. Most of the civilian population of the Aleutians were interned by the United States in camps in the Alaska Panhandle. American forces fought the Japanese on Attu and regained control of the islands. See: [[Battle of the Aleutian Islands]].

Monday, June 3, 2002 was celebrated as Dutch Harbor Remembrance Day. The governor of Alaska ordered state flags lowered to half-staff to honor the 78 soldiers who died during the two-day attack in 1942. The Aleutians World War II Campaign National Historic Area Visitors Center opened in June 2002.

On September 9, 1942, I-25 surfaced near [[Cape Blanco]], Oregon, and launched a small seaplane which dropped incendiary bombs on [[Mount Emily]] starting a few small forest fires.

From late in the fall of 1944 through the early spring of 1945, the Japanese launched more than 9,000 [[fire balloons]]. The balloon campaign caused little damage though.

http://www.military.com/NewsContent/0,13319,77031,00.html

http://www.portorfordlifeboatstation.org/article1.html