Japan government eyes autonomous probe capable of diving 7,000 meters

The Yomiuri Shimbun

18:03 JST, October 27, 2022

The government is planning to develop an autonomous underwater vehicle (AUV) capable of exploring the seabed at depths of up to 7,000 meters, it has been learned.

Such a vehicle would be able to conduct deep-sea probes in 98% of Japan’s exclusive economic zone, facilitating significant progress in seismic research and the exploration of seafloor resources. In the future, the government intends to use the vehicle to safeguard Japan’s security, according to sources.

The envisaged AUV will be 10.5 meters long, 1.3 meters wide and 1.5 meters high, and the government will aim for a maximum diving depth of 8,000 meters, the same as the deepest point in the Japan Trench. The goal is for the vehicle to be able to travel about 110 kilometers per dive and operate for 24 hours, the sources said.

Using its current Urashima AUV as the basis for development, the government is aiming to improve the ability to withstand water pressure and other features, and put the new AUV into practical use within a few years, according to the sources.

Related expenses are expected to be included in the second supplementary budget for fiscal 2022.

AUVs require no manual operation, so they can conduct safe, energy-efficient probes in the deep sea. They can likewise operate over a wide area without being connected by cables to ships at sea. The government hopes the new AUV will be utilized to study the past activity of undersea faults so as to conduct research on earthquakes and tsunami.

The new vehicle could also help create highly accurate underwater topographic maps through the use of high-frequency sound waves.

Rare earths, which are essential for high-tech products, exist in deep muddy seabeds in the EEZ. The government expects to use the vehicle to explore a wide range of seabed resources, to secure minerals that are important for economic security.

In the future, the simultaneous use of multiple AUVs will be considered, and the possibility of setting up charging facilities on the seafloor to enable longer dives.

Japan lagging behind

The AUV-Next currently has the maximum depth — 4,000 meters — among the AUVs operated by the government.

The seabed is more than 4,000 meters down in 50% of Japan’s EEZ, which is the sixth largest in the world. Work that serves as the foundation of deep-sea surveys, such as the creation of topographical maps of the seabed, has therefore been left undone.

In contrast, the United States and Britain already own AUVs capable of operating 6,000 meters down. In recent years, China has ramped up unauthorized underwater surveys in Japan’s EEZ, saying that its AUV has reached a depth of 7,000 meters. From the viewpoint of economic security, Japan must urgently develop domestic AUVs comparable to the vehicles possessed by these countries.