Quake Measured 8.1, Biggest in Five Years : Revision Based on Additional Data on Mexico Temblor; 2nd Raised to 7.5; Rescue Hopes Fade

As Mexico continued Wednesday to count the dead and began to calculate its financial losses from last week’s devastating earthquakes, U.S. scientists reported that both quakes were much stronger than first measurements indicated.

The National Earthquake Information Center in Golden, Colo., said in a news release that the official magnitude for the first temblor to strike Mexico City and four adjacent states has been revised upward to 8.1 on the Richter scale. Officials had said earlier that the quake measured 7.8.

This made the Thursday morning quake the world’s first “great” earthquake--one with a magnitude of 8.0 or more--in more than five years. The last such quake, with a magnitude of 8.0, struck the sparsely inhabited Santa Cruz Islands in the South Pacific on July 17, 1980.

The 8.1 temblor also qualified as one of the strongest earthquakes in the world since the magnitude 8.5 shock that devastated Anchorage and other parts of Alaska on March 28, 1964.

The center also said the magnitude of the second quake that struck Friday night has been revised to 7.5, up from 7.3.

The new magnitudes were computed using data from several stations around the world and were more accurate than magnitudes from a single station, the center said.

Every increase of one number on the scale means that ground motion is 10 times greater. A magnitude of 8 indicates a great earthquake capable of causing tremendous damage.

With tempers flaring among rescue workers Wednesday over the agonizingly slow pace of the recovery efforts, only rarely was there the joy of discovering a survivor here and there among the ruins. Rescuers on Wednesday pulled a baby boy from beneath tons of concrete in the capital’s General Hospital and also uncovered three more infants in the wreckage of the 12-story Benito Juarez Hospital.

“He was hurt a little bad, but I think he’s going to live,” Capt. Fredric Pierre of the French rescue team said of the infant who was found deep in the ruins of General Hospital. The child apparently survived because the corpse of an adult shielded him from the wreckage.

Pierre said that a woman also was saved at General Hospital late Tuesday, after an 11-hour effort, and that one of her legs had to be amputated to extricate her.

The Mexico City Police Department pushed its official death toll up to 4,596 and said more than 11,700 were injured, of whom 1,700 remained hospitalized.

Based on Aerial Survey

U.S. Ambassador John Gavin said his initial estimate of 10,000 deaths, based on an aerial survey, was “probably relatively correct, I’m afraid.”

In a press briefing, Gavin also announced the death of a sixth American and said another 28 Americans were still missing. Many of the missing had been staying at the Hotel Regis, which collapsed in the first quake, and are presumed dead. The sixth American fatality was identified as Bruce Sloan of New Market, N.H., who died in a hospital.

“Time is running out, but we are still trying to find people alive,” Gavin said. “By Thursday, we will have very slim hopes of rescuing anyone alive.”

The Mexican government continued to report that at least 2,000 people are still buried in the rubble, but many people here doubt the accuracy of that figure and of other government casualty figures. The number said to be trapped has changed little in four days, though each day, the death toll has crept upward.

There was suspicion here that the government may be underestimating the toll out of concern for the country’s image abroad.

Casualty figures in other disasters have been controversial, too. When a government-owned gas distribution facility exploded in a crowded Mexico City neighborhood last November, the death count climbed for days and then froze at 400. The government finally raised the toll to 500, but neighborhood residents and the families of missing workers insisted that twice that number were lost.

Meanwhile, foreign technicians began wiring explosives to shaky buildings in preparation for demolition. Despite protests from distraught families who want the search for survivors and bodies to continue, the government moved ahead with plans to blow up or raze at least 300 damaged buildings.

Revision of Building Codes

President Miguel de la Madrid ordered a revision of building codes after criticism that many structures were poorly maintained or precariously built. He said his government will consult architects and other experts about the need for regulations on building heights and wall thicknesses. The announcement was greeted with some skepticism; because of Mexico’s long tradition of bribes and corruption, building codes have been highly elastic.

Engineers from the Engineering Institute of the National Autonomous University ventured the first estimate of the damage to Mexico City’s infrastructure--between $1 billion and $2 billion. More than 400 buildings were demolished by the back-to-back quakes, and another 300 were severely damaged.

The institute’s damage estimate does not include lost wages, ruined equipment, lost services and the income that the tourist industry has foregone as foreign tourists have abandoned the city.

$250 Million in Claims

Insurance companies already have received claims of $250 million for earthquake damage.

The government, which released no damage figures, made overtures for special treatment from international bankers to help ease an already large debt burden certain to be aggravated by the heavy costs of reconstruction. Mexico’s foreign debt already stands at $96 billion, and 40% of its earnings are devoted to servicing the debt.

“We recognize that the fundamental effort will be ours,” said De la Madrid. “But, yes, we ask that the international community understand our problems and our financial and commercial relations, so that we can handle them in such a way to help us absorb the economic impact of this tragedy.”

Saving the living remains the government’s highest priority, De la Madrid said during a tour of the city. “We’re going to try to renew our efforts and make every rescue effort.”

The life-or-death decision on whether to abandon the search for the living continued at several wrecked buildings.

2 More Survivors Found

French-trained search-and-rescue dogs may have come across two more survivors at the Hotel Regis, one of the most devastated buildings in the capital.

Frustrations over rescue efforts strained tempers at several rescue sites as long hours passed without finding a survivor. Fumigation and wrecking crews stood by, ready to disinfect and demolish ruins declared to be without survivors.

At the downtown Conalep Technical School, the relatives of students trapped inside shouted insults at rescuers who, they said, were working too slowly.

“They’re not doing anything!” shouted Fernando Pardo, an architect, hoping that his son will still be found alive.

Rescuers have found no survivors at Conalep for more than two days. The overwhelming stench of decomposing flesh indicated that many, if not all, of the victims left inside were dead.

The Conalep school, like many of the badly damaged buildings in central Mexico City, was flattened in a way that Mexicans now call, in instant earthquake slang, al pastel-- like a layered cake.

Arguments Among Rescuers

At the devastated Juarez Hospital, arguments broke out among foreign rescue crews over whether any survivors remained in the debris.

In addition, police had to fight off about 1,000 relatives of victims trying to storm the back fence of the hospital seeking quicker information. Some of the desperate relatives called out, “We want information, good or bad!”

Meanwhile, the Mexican legislature began to study changes in Mexico’s building codes. Engineers said previous revisions had not foreseen earthquakes as powerful as last Thursday’s.

“The intensity of the earthquake has made the code based on estimates made in the last revision, in 1976, obsolete,” said Emilio Rosenbluth, an engineer at the National Autonomous University.

Buildings that went up before the latest code went into effect were especially vulnerable to the powerful quake, because they were constructed under even less demanding standards.

Esteva Marabota, head of the Engineering Institute at the National Autonomous University, cautioned against expecting a major revision of the code. “The codes will have to be looked at,” he said, “but there is the danger of making the cost of building prohibitive.”

Building Practices Blamed

Other observers suggested that building practices rather than codes were at fault. “The problem is not the regulations, which are some of the best in the world, but faulty supervision of the jobs,” said Ricardo Ricaud, an architect. Sometimes in Mexico, costs are shaved during construction and bribes are paid to inspectors to overlook construction faults, he said.

Government officials, faced with speculation that corruption might have contributed to destruction of many buildings, pointed out that only about one-tenth of one percent of the city’s buildings were destroyed or badly damaged.

Rescues hampered by egos, language differences. Page 22.