Воскресенье, 28.05.2017
Мой сайт
Меню сайта
Категории раздела
Eastern Sierra [1]
Idaho [1]
Montana [1]
Los Angeles [26]
California [2]
art [1]
Статистика

Онлайн всего: 1
Гостей: 1
Пользователей: 0
Форма входа
Главная » 2013 » Декабрь » 3 » San Andreas Fault
06:35
San Andreas Fault
The First 15 Minutes   by Ryan Deto LA Weekly Photos from the week of November 24, 2011
 

Peggy Gooday sits paralyzed on her sofa as the world outside shrieks with an unearthly roar. The sound of millions of bits of lumber, metal, concrete and glass twisting and shattering echoes as downtown Los Angeles plunges into darkness. Gooday's TV is launched off its pedestal and smashes at her feet. Paintings jump from their hangers. Her clattering cup of tea falls off the coffee table and splashes onto her carpet.

Gooday's eighth-floor apartment in the historic Alexandria Hotel at Fifth and Spring streets is convulsing like a paint shaker, and her emotions race from fear to fascination and back. All she can do is sit, immobile, in her suddenly pitch-dark domicile.

Gooday says: "I would probably try to grab my glasses above anything. ... I am not prepared, I don't have a radio — or a flashlight
 

The Big One, the rupturing of the San Andreas Fault, which will bring Southern California to its knees, has just begun.


This scenario is hypothetical. Gooday and others were asked by L.A. Weekly to envision their actions during the 15 to 20 minutes after the earthquake — a crucial window of time in which the fates of thousands are sealed, and in which civilians must rely on themselves. Emergency crews will be rushing to major catastrophes, and cellphones and landlines will be dead or jammed.


To determine which communities will be left in ruins and how people will react, the Weekly interviewed some two dozen geologists, sociologists, researchers and others; examined detailed permits showing which buildings have not been quake-retrofitted; and analyzed the ShakeOut Scenario, a 312-page report by 300 scientists at the United States Geological Survey (USGS), which explains the likely consequences of a colossal quake on the southern San Andreas Fault.


The USGS, based at Caltech, predicts the chance of a dreaded Big One hitting in the next 30 years at about 37 percent. That's high. An earthquake struck Virginia this year — yet the area had been given just a 4 percent chance of an occurrence.


The Weekly used the ShakeOut Scenario's postulated 7.8 earthquake and set the disaster date on a cool November night during Thanksgiving week of 2011, at precisely 7 p.m.; its epicenter is 100 miles away, in the dying desert hamlet of Bombay Beach on the eastern shore of the Salton Sea.


Scientists say the rupturing of the strike-slip fault will last an interminable 55 seconds. The 1994 Northridge quake, described by some as "endless," lasted seven seconds.


The nearly one-minute rupture will be followed in some areas by up to four terrifying minutes of seismic waves as the Los Angeles Basin — with its 30,000-foot-thick layer of sediment upon which about 10 million people live — shudders like Jell-O, violently jostling everything built upon it.


Precise predictions about which buildings will pancake or crumble, and whose neighborhoods will burn, are impossible.


"It's a fool's game to guess too much what area will be hurt the most," says Kate Long, earthquake and tsunami program specialist for California Gov. Jerry Brown, "but the places with older, brick buildings, like Hollywood, are bound to suffer significant damage."


"If I had to guess a place that would be hit hardest," says Caltech engineering professor Thomas Heaton, "it would have to be San Bernardino."


That city, recently rated the second poorest in the nation behind Detroit, immediately borders the San Andreas Fault. San Bernardino building official Justin Lease says that, after rescinding its retrofitting ordinance in 1999 because property owners said it was too costly, the San Bernardino City Council allowed about 100 buildings to forgo work needed to prevent collapse.


But beyond such guesses, general truths are known about how people will die and which areas will be destroyed in this inevitable, cataclysmic event.


In L.A. proper, the USGS Shaking Intensity Map shows that the harder-hit areas will be the Eastside, downtown, South L.A. and central districts such as Hollywood. The Wilshire District, the Westside, San Fernando Valley and the coast will be better off — largely because the San Andreas cuts through San Bernardino County and northern parts of L.A. County and thus is farther from these areas.

After the initial shock wreaks havoc, minutes of long-lasting seismic waves will indiscriminately damage scores of Southland cities. Within Los Angeles County, 73 of the 86 cities — including most of Los Angeles itself — are perched atop the L.A. Basin deposit, whose sediment is so deep it could fully immerse Mount Everest.

Kimberly Shoaf, a UCLA disaster expert who was among the 300 scientists who created the ShakeOut study, says the rupture and seismic waves will set off thousands of fires, which will kill 50 percent of those who die from the Big One. Some 70 percent of those blazes will be in residential areas.

Despite extensive efforts at earthquake retrofitting, 40 percent of the deaths — and 90 percent of the injuries — will be caused by building collapses and lesser damage, such as falling decorative beams or air-conditioning units. The remaining 10 percent of deaths will be transportation-related: Cars, trucks and buses will crash, fall or be flattened; rail and subway cars will derail or be crushed; bridges and roads will buckle or topple.
 

The region has undertaken laudable defensive measures. Caltrans insists that all state-owned bridges are safe, for example, and thousands of Southern California buildings have been retrofitted. And thanks to tough statewide seismic building codes, commercial and residential structures will perform better than those in the Great Hanshin quake, which wrecked Kobe, Japan, in 1995. Kobe, whose leaders had wrongly boasted of superior quake construction, suffered 6,400 deaths. Some 80,000 buildings were ruined beyond repair.


But geologists agree that the duration and intensity of the Big One will create a catastrophe the likes of which L.A. has never known. It will be as deadly as Hurricane Katrina and more than twice as costly, killing 1,800 people. And as USGS seismic scientist Ken Hudnut notes, the scientists who created the ShakeOut data have settled upon safe, conservative estimates.
 

Downtown Los Angeles will be hit hard by the monstrous quake. City leaders recently granted $640 million in taxpayer subsidies to three new hotels. They've provided billions more in public subsidies to downtown developers over the past 30 years.


Downtown might not have been the best place for the Los Angeles City Council, mayors Antonio Villaraigosa, James Hahn, Richard Riordan and Tom Bradley, and the Community Redevelopment Agency/Los Angeles to concentrate vast sums of public-development money.


Most new skyscrapers will suffer relatively minor damage, but they'll be sitting in the midst of vast destruction.


In the 1994 Northridge quake, several historic buildings such as the Alexandria Hotel and L.A.'s first skyscraper, the Continental Building, escaped damage and received "green" safety ratings rather than yellow or red unsafe ratings. The buildings that got green ratings escaped complying with full seismic retrofits required of buildings seriously damaged in that temblor. The ironic result: These passed-over buildings aren't ready for the Big One.


Moreover, despite Caltrans' upbeat assessment of its bridges, a new report from U.S. policy group Transportation for America says motorists in L.A. drive on structurally deficient bridges more often than residents of any city in the United States, some 400 cars every second.


The L.A. County Department of Public Works is repairing 11 nonretrofitted bridges, but 14 others in L.A. remain a threat, including downtown's decaying and heavily used Sixth Street Bridge to Boyle Heights, which is slated for demolition and replacement.


Now, many of these unfortified buildings and bridges will crumble or break apart.


"Society tends to be reactive," says University of Colorado earthquake engineer Keith Porter. "It takes something to hit us before we actually do something about it."


Individual scientists say that hundreds of buildings within the City of Los Angeles could be badly damaged, while USGS predicts that five large buildings will collapse entirely — another admittedly conservative estimate.


Downtown, Hollywood, the Eastside and the huge Wilshire District have dense concentrations of potential killer buildings, but downtown is the most susceptible. It and the Eastside will take a harder hit from the seismic waves, and downtown has rows of old buildings in higher concentrations than other districts.


Last month, Villaraigosa told L.A. Weekly that the city's nonretrofitted buildings "are some of the things we are going to have to look at."


A few days later, on Oct. 27, the mayor rattled nerves by declaring that the Sixth Street Bridge, used by thousands of Eastside motorists traveling to and from downtown, will need $401 million in repairs to make the bridge safe.


That money may be hard to get. "L.A. doesn't just go to Washington with its hand out,'' Villaraigosa said in a press release. But "you know cities can't build and rebuild their airports, their ports, their freeways, their public transportation systems all at the same time."


6:59 p.m., seconds before the quake:


Inside her one-bedroom, corner apartment in the Alexandria Hotel, the lid on Peggy Gooday's pot of boiling pasta water starts to rattle. Gooday, watching the end of The Simpsons, hears the friendly mealtime sound echoing off her 12-foot ceilings.


But as she rises, her floor jolts back and forth violently and she's thrown into the cushions.


Though unhurt, Gooday freezes. Two bookcases spill to the floor. A short, antique ladder topples, flinging a porcelain lamp against the wall, where it shatters. When her laptop crashes off the dining room table, she snaps out of it and crawls under the coffee table.


"I understand standing in the doorway is obsolete," she remembers — and she's right. Her ring-adorned hands cover her neck, as a heavy mirror above her sofa shatters onto the coffee table.

In total darkness, Gooday closes her eyes and waits out the shaking, but she can't believe how long it lasts. She says ruefully: "People like me, well, we tend to make plans, but then we get complacent. I think, 'Yeah, I should do that,' then I watch The Simpsons instead."

The Northridge quake rupture lasted a while, too, she tells herself. In reality, the earth moved for only seven seconds (although shaking was felt for 10 to 20 seconds).

The seismic waves initiated 100 miles away are amplified by the 30,000-foot-deep pit of silt beneath most residents' feet in L.A. County. Often confused with "liquefaction" — which requires lots of groundwater — this reaction is better defined as "seismic reverberation

When the horrible shrieking from twisted metal and wood quiets, Gooday hears screams from a neighbor a few floors above her, as he is crushed by his caved-in ceiling. Soon, there's no sound from him.

Down below, at street level, two diners at gourmet restaurant The Gorbals in the Alexandria unwisely dash into the dark lobby. Other patrons dive under tables. The Alexandria's huge chandelier, with its eight frosted globes, suddenly shatters, and knifelike shards fall on the two fleeing diners, delivering mortal wounds.

Just outside the lobby, a woman and a child on Fifth Street are killed instantly, gruesomely pinned beneath the Alexandria's historic, 400-pound stone griffin, which has cleaved off a lower corner of the hotel.
 

Downtown and other older neighborhoods of L.A. contain thousands of unreinforced brick masonry buildings that will fling steel, bricks and glass into the streets. Outside the city, Los Angeles County still has 1,500 nonretrofitted brick buildings. But inside the city limits, more than 99 percent of the brick buildings have been retrofitted.


This common type of upgrade, called "life-safety" retrofitting, is solely aimed at preventing total building collapse — not at stopping killer projectiles such as flying bricks. "You can retrofit to the current minimum standard of life safety," says earthquake scientist Hudnut, "but the next level is to get to less disruption, where a building doesn't have to be evacuated, or maybe even rebuilt."


Seismic engineer Keith Porter notes that despite the effort to prevent total building collapses, "Earthquakes can always produce something different or stronger than expected. There is always a chance that life-safety [retrofits] will fail."


Thanks to California's tough seismic building codes, commercial and residential structures will perform better than those in the Great Hanshin quake that devastated Kobe.


The landmark, red-brick Bradbury Building on Third Street, built in 1893, suffers shattered glass skylights but stays intact, thanks to its $2.4 million retrofit. The 1930 turquoise art deco Eastern Columbia building on Broadway — known to millions of commuters on the 10 freeway — also stands strong due to a retrofit. The Title Guarantee building on the east side of Pershing Square, built in 1930, received a green rating after Northridge but went through bulky structural retrofits anyway. It, too, remains standing.


7:02 p.m., two minutes after the quake:


As bricks and glass crash to the streets and maim residents throughout Southern California, an even worse, and widely unexpected, disaster is unfolding in L.A.'s pre-1970s, mid-rise and high-rise concrete buildings that contain insufficient rebar for major quakes and are known to engineers and other experts as "non–ductile concrete" structures.


Inside the city of Los Angeles, 25,000 to 30,000 non–ductile concrete buildings were erected, concentrated in areas such as Hollywood, downtown and the Wilshire District. Some of these office and apartment complexes will tilt, fragment and collapse as the L.A. Basin continues to pulsate long after it's shaken. Floors will fall, façades will plunge, some will badly sway and be left askew.


Heaton says pre-1970s concrete buildings were designed to sustain only 3 feet of "displacement," or swaying, during a quake. The long-lasting seismic waves from the Big One will shift buildings more than three feet.


Moreover, Porter says the beams and columns in buildings constructed with "welded-steel moment-frames" between 1964 and 1994, which before Kobe were assumed to be earthquake-safe, will "tend to suffer brittle failure" at the welded joints. And the horrible part is, engineers and officials can't easily identify which buildings are "WSMF," or welded-steel moment-frame constructed.


"There is a big effort right now by engineers to identify these types of buildings," Porter says. "There are probably thousands and thousands of them."


A state-funded but fairly limited survey found 1,317 within Los Angeles. According to Department of Building and Safety spokesman David Lara, there is no current city, county or statewide ordinance to make retrofits mandatory, and only 1 percent of the small number of non–ductile concrete buildings identified so far have performed voluntary seismic retrofits.


Lara doesn't know if the Alexandria, technically classified as a non–ductile concrete building despite its brick exterior, is on the city's list of 15 to 25 buildings that performed retrofits. But city building records show that no seismic retrofits were made to the former hotel. The building's owner, Amerland Group, did not return calls for comment.


About three minutes after the massive jolt, the trembling slowly comes to a halt downtown. Gooday emerges from beneath her table at the Alexandria and walks to her front door. Fragments of mirror stud the soles of her purple Crocs. She dead-bolts the lock on her door. She knows the chaos is not over in her neighborhood in the city's historic Spring Street Financial District, with its mix of upscale and downtrodden residents.


Below, a group of young hipsters who'd been cheerfully heading to the rooftop bar at the Standard Hotel on Flower Street is sobbing as they pull concrete scraps off three badly hurt friends and two bleeding strangers. It's rush hour, and crashing cars have veered off Fifth Street and onto the sidewalk. Their headlights eerily illuminate the darkened, grisly scene.


Many people participate in acts of heroism and selflessness. But some see the bedlam as an opportunity to get theirs. Shop windows two blocks from the Alexandria Hotel in the Jewelry District on Hill Street are shattered by the Big One, their thick, metal security gates left badly warped with gaping openings. Young toughs scurry into the blacked-out stores like cockroaches using the cover of darkness. 
Категория: Los Angeles | Просмотров: 130 | Добавил: rostowskaja | Рейтинг: 0.0/0
Всего комментариев: 0
Поиск
Календарь
«  Декабрь 2013  »
ПнВтСрЧтПтСбВс
      1
2345678
9101112131415
16171819202122
23242526272829
3031
Архив записей
Друзья сайта
  • Создать сайт
  • Официальный блог
  • Сообщество uCoz
  • FAQ по системе
  • Инструкции для uCoz
  • Все проекты компании
  • Copyright MyCorp © 2017
    Создать бесплатный сайт с uCoz