How a False Mammoth Quake Report Got on the Air

At 11:12 p.m. Wednesday, KABC-TV broadcast a report that there had been a magnitude 5.1 earthquake in a volcanic region six miles east of Mammoth Lakes that had been subject to several swarms of much smaller quakes in previous days.

A 5.1 quake could have led, after consultations among scientists, to the highest volcanic alert ever called in the Eastern Sierra.

But the report was false.

It resulted from an initial seismographic error that misplaced a smaller quake 100 miles to the north, followed by unverified reports stemming from an anonymous, exaggerated call to a news service.

Altogether, what happened Wednesday night, as told in interviews with principals involved, points up the dangers of using quick, unverified quake information on the air, particularly in a state like California that is unusually sensitive to seismic dangers.

It almost didn’t get on the air. Channels 2 (KCBS-TV), 4 (KNBC-TV), the Associated Press and KNX radio didn’t use the report from the news tipping service, Media Page, after they called Caltech and were unable to receive verification.

At KABC-TV Channel 7, according to spokesman Bill Burton, “We actually had someone on our assignment desk on the phone to confirm, when he looked up and saw we had the story on the air.”

Around the end of the newscast at 11:35 p.m., executive producer Bonnie Wong said, KABC-TV learned its report of a 5.1 earthquake near Mammoth had been wrong, and sent a correction note to the morning news show.

But, Burton said, it was not actually corrected by the station until the next 11 p.m. newscast, Thursday night, in accord with a station policy that corrections be made in the same time slot in which the false report was made.

In Mammoth Lakes, officials sensitive to at least three false reports of volcanic eruptions or related earthquakes in the news media in the last year--two of them on Los Angeles television--expressed unhappiness.

Mammoth’s town manager, Glenn Thompson, said: “False reports do have economic effects on Mammoth, which is troublesome for people who reside here.

“Last July, KNBC showed an actual eruption that had occurred somewhere else in a report on Mammoth,” he said. “It created a small level of panic here. Those things are destructive and it seems to be a bit irresponsible.” (KNBC issued a retraction last year, just as KABC-TV issued its correction this week.)

According to interviews, this is how the latest error came to be made:

At 10:49 p.m. Wednesday, a magnitude 4.5 quake occurred 17 miles east of Markleeville in Alpine County, an area about 100 miles north of Mammoth Lakes.

Caltech and the Pasadena field office of the U.S. Geological Survey have a network of seismic stations from Southern California north to Mammoth. Caltech’s Steve Bryant, who supervises a seismic information system the school and the Geological Survey provide, said the Mammoth seismographs picked up energy from the Markleeville quake, but initially misinterpreted it.

At 10:51 and 10:52 p.m., Bryant said, in strictly private mistaken paging messages to their own scientists, Caltech and the Geological Survey said there may have been 3.3 and 3.4 quakes centered seven miles southeast of Mammoth.

The initial advisory was corrected within 15 minutes, but, in the meantime, an unknown party had monitored the message and in turn called Media Page, an 18-year-old news tipping service that services radio and television stations and Los Angeles Times photographers, with a wildly exaggerated report.

Jim Mori, head of the Geological Survey in Pasadena, said outside listeners are a growing problem for his agency and Caltech.

“Anyone figuring out how to get the pages, gets them,” he said. “But they don’t understand some of the error coding and other language. Any of us who saw that first Mammoth message would have dismissed it immediately, because it was coded as of questionable reliability.”

But Tom Kravitz, owner of Media Page, said the unknown monitor told his Orange County bureau staffer, Scott Miller, that Caltech was saying there had been a 5.1 quake six miles east of Mammoth.

A 5.1 quake would have been 40 times more powerful than the 3.4 to which the original message referred.

But Kravitz said that Miller, who did not know who his informant was, quickly put out a message to all Media Page clients that there was “a report” of a Mammoth quake.

“We were not saying this was confirmed,” Kravitz said. “That’s why we used the word ‘report.’ ”

Wong, the executive producer of KABC-TV’s 11 p.m. news, said the Media Page message reached the station just after the newscast went on the air.

“By the time we found out it was wrong, it was around the end of our show and it was too late for us to correct it,” she said.