Deadly, Explosive Mt. Unzen Is the Unlikely Star of New Japanese Cable TV Service : Volcano: The early warning system allows residents at base of peak to rest a little easier.

It keeps them up to date. But the new cable television service piped to Shimabara residents could cause a nasty case of mass indigestion if Mt. Unzen ever erupts while they are eating.

Fearing another deadly explosion by Unzen, which awoke from a 200-year slumber just a year ago, the people of this former resort town have set up an early-warning system that brings live images of the volcano into homes, offices and restaurants.

Cable Television Shimabara started broadcasting round-the-clock coverage of the crater in August after a huge eruption June 3 killed more than 40 people and drove 10,000 from their homes on Unzen’s slopes. Now it has 500 subscribers.

“Our customers always watch the screen while they’re drinking,” said Fumika Takagi, owner of a Japanese-style pub near the center of Shimabara.

“The live coverage certainly gives our customers a sense of security,” she said.

“Before I put in the set, our customers and myself often went outside with binoculars to watch the volcano,” said local hotel owner Kimie Iwanaga. “Now we can watch it any time in the dining room.”

For the first few months after Unzen reawoke on Nov. 17, 1990, Shimabara’s 46,000 residents were little troubled by the gases venting from the summit that overlooks the town.

Tensions grew, however, after the June 3 eruption rained rocks and dust on Shimabara, which lived for weeks in a choking poisonous fog. The tourist industry ground to a halt.

“The local residents have had no time to feel at ease over the past five months, even while they sleep,” said city official Yoshikazu Yamakita.

The cable television network helped local government work out emergency measures and communicate with residents, he said.

Postal authorities, for example, used to station men at several points in the surrounding area to alert headquarters of volcanic activity to ensure the safety of mail carriers on duty.

“When a pyroclastic flow occurred at night, the whole TV screen turned red,” pub owner Takagi said.

Pyroclastic flow is a scientific term for a deadly cloud of hot gas, ash, rock and lava debris pouring from the crater.