[Risks and preparedness for Mt. Fuji eruption] Experts explain the impact on railways, electricity, communications, etc.

What was the impact of the Mt. Fuji eruption? (Photo/Jiji Press)

　The "Mt. Fuji Hazard Map" will be revised for the first time in 17 years in 2021 to interpret the extent of damage and expected time for each eruption of Mt. Fuji. Will Mt. Fuji erupt really happen? If Mt. Fuji really erupted, what kind of impact would it have on urban functions? Know the worst that can happen after an eruption and prepare for it. [List] Introducing the effects of volcanic ash from the eruption of Mt. Fuji, divided into transportation, lifelines, etc.

"If volcanic ash accumulates on the rails due to the eruption of Mt. Fuji, approximately 1,800 km of railways around Mt. Fuji will stop," says railroad journalist Atsushi Umehara. "In a railway, in addition to the electricity for running from the overhead wire, the train position is grasped by the signal current from the rail, and the signal, barrier, alarm, point switching, etc. are remotely controlled. The track. When volcanic ash accumulates on the rails and the electricity stops flowing from the rails to the wheels, the signal current necessary for safe operation is blocked, and the signals and circuit breakers cannot be operated, resulting in early suspension of operations. prize"

If ash accumulates on the railway, trains will stop running early

　The weak point of modern people who rely on electricity is the bad effect of volcanic ash on electricity. "It could adversely affect power plants and transmission systems, and in the worst case, blackouts (massive blackouts) in the Tokyo metropolitan area," said crisis management adviser Nobue Kunizaki. "When the volcanic ash that accumulates on the insulators of the equipment that supports the electric wires gets wet with rain, it leaks, and the safety device is activated, preventing power transmission. In addition, volcanic ash piles up on trees, etc., and touches electric wires, causing disconnections and short circuits, resulting in power outages. In some cases, there are also cases where the power supply cannot keep up with the power supply due to the clogging of the outside air intake filters of the thermal power plant and the ash fall on the solar panels. It can be said that it is essential to prepare storage batteries, EVs (electric vehicles), solar chargers, etc.

Ashes on antennas and power outages cause smartphones to be out of service

　In times of disaster, smartphone communications are often restricted, but when volcanic ash falls and mobile phone base stations stop functioning, "smartphones" is likely to become unusable as both a phone and a data terminal," said Atsushi Ishikawa, a mobile journalist. “If volcanic ash adheres to the antennas of mobile phone base stations due to rain, it will cause communication failures that make it difficult to make calls. It is installed every km, but if the nearest base station stops functioning, it will be out of range in the vicinity.