What was intended as a message to lessen earthquake worries caused confusion among some Hawaii television viewers yesterday when TV screens showed an emergency alert without sound.

Pete Cronburg, who lives in the Punchbowl area, said he felt a tremor, then saw a written “;earthquake”; message across his TV screen 15 minutes later.

“;It did not repeat,”; he said. “;Concerned about a possible ocean wave created by earth movement, I went online but could find no current report anywhere.”;

While the earthquake was not enough to generate a tsunami, it generated a wave of telephone calls.

State Civil Defense spokesman Ray Lovell said the receptionist at Civil Defense received about three dozen calls within 25 minutes.

The Hawaiian Volcano Observatory said it received more than 300 reports from people who felt the earthquake, some from as far away as Oahu.

Lovell said the text message about the earthquake was viewed on television stations. But he said the cable channels without broadcast air television systems on Oahu did not carry the voice message about the earthquake causing no tsunami.

In addition, Lovell said, viewers were directed to channel 48 to listen to the alert, but the voice message did not go on channel 48 on Oahu, although it was heard on other islands.

“;Something went wrong,”; Lovell said. “;There is an ongoing effort to make things as foolproof and simple as possible.”;

Lovell said Civil Defense was still looking into the sources of the confusion.

The earthquake, about 10 miles north-northeast of Laupahoehoe at a depth of 12 miles, was 4.0 in magnitude and occurred at 9:44 a.m., according to the U.S. Geological Survey. There were no reports of injury or damage, Big Island Civil Defense said.

The Pacific Tsunami Warning Center initially reported the magnitude at 5.2 but later downgraded it.

Warning center Assistant Director Stuart Weinstein said the discrepancy in the quake's magnitude was caused by the difference in the methods of measurement.

Tsunami warning officials measure the initial movement of a quake and send out a quick notice to Civil Defense and news media outlets, whereas the U.S. Geological Survey measures an earthquake over a five-minute period, authorities said.