Critic Raps State on Malibu Fault’s Status : Earthquakes: An expert who wants the web of fissures to be declared active questions the chief geologist’s ethics.

MALIBU —  A geology professor who has extensively studied the Malibu Coast Fault accused state officials last week of acting unethically and against the interests of area residents in failing to designate the fault as active.

Speaking at a national meeting of geologists in Cincinnati, Vincent Cronin, an assistant geology professor at the University of Wisconsin-Milwaukee, said more than 600 earthquakes, have struck along the fault since 1911. Many of them have been minor, although one was as strong as magnitude 5.9.

Yet, he charged, “certain public officials and private consultants seem to be unable, unwilling or remarkably slow to recognize that the Malibu Coast Fault Zone is seismically active.” Such recognition is necessary to allow tight regulation of construction within 50 feet of fault branches, as authorized under California’s 20-year-old Alquist-Priolo Act.

Cronin made his remarks at a session of the Geological Society of America’s convention. Asked in an interview to whom he was specifically referring, Cronin named California’s state geologist, James F. Davis.

“Jim Davis has played a role in trying to ensure the Malibu Fault was not declared an active fault,” Cronin said. “I really don’t know what his motive may be.”

Later, in his presentation, Cronin said: “An ethical scientist collects all relevant available data, analyzes the data in a valid manner and makes a defensible interpretation. . . . The principal client of all engineering geoscientists is the public, and our ethic decisions must be dominated by the legal and moral necessity to protect the public’s safety.”

Because the fault has generated a sizable number of earthquakes, there should be no problem in finding it to be active, he said.

Davis, who was also attending the Cincinnati meeting but left the day before Cronin made his presentation, told The Times that he would not respond to secondhand reports of an accusation he had not personally heard.

Davis said, however, he would have hoped that Cronin would have held off on his observations until release of a seismic report on the Malibu area that is being prepared for the state Conservation Department’s Division of Mines and Geology. He said it should be released by the end of the year.

“We have a premium on getting it done as soon as possible, but we keep having interruptions like the Parkfield tremors and the Landers earthquake,” Davis said.

The Malibu Coast Fault is actually a web of faults that run parallel to the coast for most of Malibu’s 20-mile length. Some of the branches, known as strands, are onshore and others run beneath the ocean.

Under the Alquist-Priolo law, if the Malibu Coast Fault is designated as active, a special study zone would be created to ascertain all locations where the underground fault extends to the surface. Such spots, known as traces, would be subject to construction restrictions, Davis said.

Generally, Davis said, a special study zone extends 500 feet from known traces. Building regulations, which can be imposed by the local government once a fault is formally judged to be active, generally forbid construction of high-occupancy structures, such as schools or commercial projects, within 50 feet of a trace of an active fault, and strictly limit other construction.

Last February, The Times disclosed that an internal recommendation in Davis’ department had declared that only a half-mile section of the more than 45 miles of perceived fault strands under Malibu be given the “special studies zone” designation. If such a preliminary recommendation were to be formally adopted, the Malibu city government would be severely limited in its ability to restrict construction under Alquist-Priolo.

Although the law gives the final say on such limitations to local governments, it was found after the June 28 Landers earthquake that, despite the law, residents had often been permitted to build right up to the fault line.

Some homes were destroyed by fissures that ran right below them, and there has since been debate over a possible strengthening of the act.

Also present in Cincinnati last week was James Slosson, a former state geologist who is one of 15 members of the California Seismic Safety Commission. He, like Cronin, has long been associated with demands that the Malibu fault be declared active.

In an interview, Slosson said the fault is a thrust fault, in which ruptures tend to dissipate before they reach the surface of the Earth, leaving relatively few visible traces. Many of the Alquist-Priolo definitions, written with strike-slip faults, such as the San Andreas in mind, do not apply very well to thrust faults, experts said.

“Since the law addresses only surface rupture, that would cause less than 1% of damage to property that would be caused by a strong earthquake on the Malibu Coast Fault,” Slosson said. “Ninety-nine percent of the damage would result from shaking, landslides and so forth.”

So, Slosson said, he and other experts favor a redefining of terms in a strengthened Alquist-Priolo Act, which would allow construction standards to be set over a wide area within a fault zone.

Despite resistance by property and construction interests to such amendments, Slosson insisted that the net additional cost of giving new dwellings and commercial buildings a strong degree of protection from a sizable quake would amount to only 1% to 2% of total construction costs.

“I think Jim Davis is sticking to the letter of the law of the present Alquist-Priolo Act,” he said.

In his presentation, Cronin, speaking in general terms and not referring to Davis by name, said he could not explain for certain why there has been such resistance to designating the Malibu fault as active. But, he said, “money and politics come to mind.”

He said studies of the fault and existing records show that there have been at least 21 earthquakes in the last 80 years of magnitude 3.9 or greater, and three quakes since 1970 of magnitude 4.9 or greater. The fault zone has at least two active branches, the Malibu Fault onshore and the offshore Dume Fault.

“To me, this is as much a problem of professional and scientific ethics as it is a technical problem,” he said. “Interpretations made by ethical geoscientists are the same regardless of whether they have a personal, professional or financial stake in the outcome.

“After all,” he said, “the public has invested heavily in our costly education. They expect, and have a right to expect, that we use our technical skills in the public interest.”

He added: “Let’s face it, when a petrologist or a paleontologist makes a mistake, who cares? When an engineering geoscientist makes a mistake, the lives and property of innocent people are placed at risk or are lost. That is why registration laws for geologists exist. The public places their trust in our technical competence, and we must validate that trust with thoughtful and competent performance.”

The Malibu Coast Fault

The Malibu Coast Fault is really a web of faults that comes ashore in eastern Malibu and stretches across much of the 20-mile-long city before returning to the sea west of Point Dume. The dark line represents what geologists generally consider to be the fault’s main trace. Some of the smaller splays, or branches, of the fault are indicated by broken lines.

A preliminary recommendation by the state calls for designating only the Latigo Canyon Splay as a “special studies zone” under the 1972 Alquist-Priolo law. Discovery of evidence of recent seismic activity at a site near Pepperdine University in the 1970’s forced General Motors Corp. to drop plans to build a research facility.