能登半島地震で海岸線が大きく変化しました。
最初に能登半島地震で亡くなられた方々のご冥福をお祈りいたします。
また、ご家族を亡くされた方々にお悔やみ申し上げます。
並びに、被害を受けた方々にお見舞い申し上げます。
能登半島地震は、阪神淡路大震災以上の規模でした。
１月１日に発生した能登半島地震から１週間が過ぎました。今回の地震は、大規模な地震が複数回発生し、被害も拡大してしまいました。最大震度７を記録した地震は、輪島の東北東30km付近が震源で、マグニチュード7.6を記録しました。近年発生した大きな地震では、１９９５年の阪神淡路大震災と２０１６年の熊本地震で、それぞれマグニチュード7.3でした。東日本大震災のマグニチュードは9.0、関東大震災が7.9だったので、能登半島地震は記録が残されている地震では、日本では３番目に規模が大きな地震となりました。おそらく、これから明らかになる被害状況は、甚大となることでしょう。
能登半島地震は、地形が変わるほどの地震でした。
能登半島地震の前後で、能登半島の大陸側海岸が隆起していることが観測されていました。また、大陸側に移動している地点もあり、例えば輪島市の皆月湾周辺では海岸線が沖に約200メートル進んだ場所もありました。その結果、海底地形や海岸線が大きく変化してしまいました。その結果、漁港や商港が破壊され、港に船舶が着岸できなくなりました。主要道路が寸断され、大規模な救援物資の陸上輸送が困難であるため、海上輸送は重要な輸送経路でした。特に被害が大きい志賀町や輪島市の海岸線は大きく大陸側に移動し、海岸線の道路は寸断されました。そのため、輸送船など大きな船が着岸するためには、港の再建が必須でしょう。そして、港の再建には海底地形の把握が必要となるでしょう。特に再建する港付近の水深と海底地形は、出入港する船の安全な航行のため、必須のデータとなります。これらデータの取得に水中ドローンが利用できないか、と考えております。
震災時の海上輸送を行うために、洋上港設置はできないでしょうか？
洋上港は、大きな船を停泊させるために沖合に置かれる港です。大きな船は喫水が深いため、水深が深い所でないと航海できません。そのため、特別に整備された港以外、接岸・停泊できません。例えば、メガフロートなどを利用して、沖合に洋上港を設置できないでしょうか？もちろん、まだ余震が続いていて、大きな余震や津波が発生する可能性もあるため、安易に新しい試みはできないと思います。しかし、南海トラフ地震の発生も予測されているので、震災時の海路利用について準備しておくべきではないでしょうか。震災時は陸路が寸断されているため、支援物資の貯蔵や搬入拠点として、洋上港の設置が有効だと思います。
#能登半島地震 #復興 #水中ドローン
The coastline has changed significantly due to the Noto Peninsula earthquake.
First, I would like to pray for the repose of the souls of those who lost their lives in the Noto Peninsula earthquake.
I would also like to express my condolences to those who have lost their families.
We would also like to express our sympathies to those affected.
The Noto Peninsula earthquake was larger than the Great Hanshin-Awaji Earthquake.
One week has passed since the Noto Peninsula earthquake that occurred on January 1st. This earthquake caused multiple large-scale earthquakes and caused extensive damage. The earthquake, which recorded a maximum seismic intensity of 7, was centered around 30 km east-northeast of Wajima and had a magnitude of 7.6. Major earthquakes that have occurred in recent years include the Great Hanshin-Awaji Earthquake in 1995 and the Kumamoto Earthquake in 2016, each with a magnitude of 7.3. The Great East Japan Earthquake had a magnitude of 9.0 and the Great Kanto Earthquake had a magnitude of 7.9, making the Noto Peninsula Earthquake the third largest recorded earthquake in Japan. It is likely that the damage that will be revealed in the future will be enormous.
The Noto Peninsula earthquake was strong enough to change the topography.
It was observed that the continental coast of the Noto Peninsula was uplifting before and after the Noto Peninsula earthquake. There are also places where the coastline has moved toward the continent, such as around Minazuki Bay in Wajima City, where the coastline has moved approximately 200 meters offshore. As a result, the seafloor topography and coastline have changed significantly. As a result, fishing and commercial ports were destroyed, and ships could no longer dock at the ports. Maritime transport was an important transportation route, as major roads were cut off and it was difficult to transport large-scale relief supplies by land. The coastlines of Shiga Town and Wajima City, which were especially hard hit, moved significantly toward the continent, and roads along the coastline were cut off. Therefore, in order for large ships such as transport ships to dock, it will be necessary to rebuild the port. In order to rebuild the port, it will be necessary to understand the seafloor topography. In particular, the water depth and seafloor topography near the port to be rebuilt are essential data for safe navigation of ships entering and leaving the port. We are considering whether underwater drones could be used to acquire this data.
Is it possible to set up an offshore port for marine transportation in the event of an earthquake?
Offshore ports are ports located offshore for the purpose of berthing large ships. Large ships have deep drafts, so they can only sail in deep water. Therefore, ships cannot berth or berth at ports other than those that have been specially developed. For example, could we set up an offshore port offshore using mega floats? Of course, there are still aftershocks, and there is a possibility that large aftershocks or tsunamis may occur, so I don't think we can easily try something new. However, since a Nankai Trough earthquake is predicted to occur, we should prepare for the use of sea routes in the event of an earthquake. Since land routes are cut off in the event of an earthquake, I think it would be effective to establish an offshore port as a base for storing and transporting relief supplies.
#NotoPeninsulaEarthquake #Reconstruction #UnderwaterDrone
