Earthquakes

The state Thursday released a series of maps that show an expansion in liquefaction zones signifying earthquake hazards in parts of the east San Fernando Valley, including an area from the San Diego Freeway east to Burbank. The release of what were described as tentative maps--to be made official in the next three years--represented a step toward requiring by the end of 1998 costly safety studies for new apartment houses and commercial buildings in quake-endangered zones.

The state Thursday released a series of Southland earthquake hazard maps in a step toward implementing mandatory safety studies for new apartment houses and commercial buildings in quake-endangered zones by the end of 1998. State Geologist James Davis said that when the maps are made official, local governments will--under state law--have to require seismic hazards evaluations "to validate the level of hazard at the site and make appropriate recommendations for mitigation."

As a jarring bell pierced through the halls at Byrd Middle School in Sun Valley on Tuesday morning, the 21 eighth- and ninth-graders in Penelope McMillan's English as a second language class scrambled under desks and covered their heads to prepare for an impending 7.1-magnitude earthquake. But little shook in the classroom, except for the few desks that students rattled to simulate the shaking of a massive temblor.

One of the last Catholic schools in the San Fernando Valley to recover from the 1994 Northridge earthquake will break ground next month for a $2.1-million school building. Mary Immaculate School has been getting by for 2 1/2 years with portable classrooms for kindergarten through eighth-graders from the largely Spanish-speaking community.

Most people think of an earthquake as a fearsome release of earth energy measured in seconds--still long enough at its most severe to topple the tallest buildings or remake a mountain range. But in research made public Wednesday, scientists at the Carnegie Institution of Washington show how some earthquakes can last hours, even days. Indeed, they present evidence of a magnitude 4.

Japanese and American science officials have agreed on a new earthquake research partnership between the two countries, significantly expanding two 20-year-old science pacts. One of the earliest projects of the Earthquake Disaster Mitigation Partnership will be a Japanese-financed but jointly designed shake table in Japan that will be the world's largest to date.

One part of the crumbling Rossmoor Wall will be fixed within the next few weeks in a move that attorney Richard H. Oftedal and other homeowners hope will help cement community support for repairing other portions of the controversial red brick structure. The wall, which straddles parts of Los Alamitos, Seal Beach and unincorporated Rossmoor, needs an estimated $100,000 worth of repairs. The wall was damaged in the Landers and Northridge earthquakes.

An assistant professor at Chapman University is challenging a widely accepted model for earthquake prediction in an article in Science magazine. "Instead of revising the old model, maybe it's time to start thinking of a better one," said Lisa B. Grant, who holds a doctorate in geology and geophysics.

Q: Do earthquakes occur more often during hot weather or in the early morning hours? Is there earthquake weather? A: No, according to seismologist Lucile Jones of the U.S. Geological Survey. Sixty-two years of records at the USGS show that earthquakes occur randomly at all hours of the day and at all times of the year. Although scientists have looked intently for patterns in quake occurrence, they have never found any.

In April, Charles G. Sammis, chairman of the USC geology department, said he expected a magnitude 6.0 to 6.5 earthquake to occur in Central California by July 9. He based his prediction on an upsurge since 1987 of quakes above magnitude 3.0. The earthquake didn't happen, one in a long line of failed quake prognostications. "The fact that the window ran out shouldn't confuse people," Sammis said a bit defiantly in a later interview. "Seismic activity is still increasing in the area.