In a Scientific First, a Cosmic Ray Sensor Detected Tsunami Waves

We are all aware of the devastating impact that tsunamis can have, and the potential for tragedy continues to drive research into improved detection methods. The monitoring of muons is a more usual approach to detecting the waves.

100,000 of these particles will pass through your body while you read this sentence, because they are created as Cosmic rays arrive from space, are everywhere in the atmosphere, and can harmlessly pass through just about anything.

They can be slightly shifted in their path by large natural forces.

The Tokyo-Bay Seafloor Hyper-Kilometric Submarine Deep Detector, or theTS-HKMSDD, is an incredibly sensitive instrument that is required to detect muon movement. It is inside the Tokyo Bay Aqua-Line expressway tunnel.

For the first time, the TS-HKMSSD was able to detect waves through muon ripples. The detection happened in real-time and was shown to be highly accurate.

The Tokyo-Bay Seafloor Hyper KiloMetric Submarine Deep Detector is the first underwater muon observatory in the world, and it detected varying muon activity during the tsunami.

The variation corresponds to the ocean swells which were measured. We can use muographic data to accurately model changes in sea level, instead of using other methods which have drawbacks.

Satellite imagery taken from above and various sensors in the sea are some of the other methods. Muon detection promises to be cheaper and easier to maintain than those approaches.

The new research shows how a typhoon caused a mild wave to pass through Tokyo Bay in September 2021. The number of muons changed as the ocean grew.

The researchers suggest that instruments like it could be installed in other tunnels in areas at risk of tsunamis and used alongside equipment such as tide gauge as part of early warning systems.

Thanks to the success we've had from early tests such as this, similar systems are already being trialed in the UK and Finland.

Installation of delicate instruments in a busy tunnel could be difficult. The agencies responsible for the Tokyo Bay tunnel cooperated with us.

The muon detectors that make up theTS-HKMSSD are small, around 2 meters in length. The road tunnel under Tokyo Bay is home to 20 of them, working together to create the overall system.

A system like this could be used to look for natural gas reserves, as well as detect approaching tsunamis.

The researchers are happy to have the TS-HKMSSD up and running, which will allow them to alert experts to natural disasters.

To the best of my knowledge, the tunnel is the first active national road in the world.

The research has been published.