Great Hanshin earthquake were from Kobe. Among major cities, Kobe, with its population of 1.5 million, was the closest to the epicenter and hit by the strongest tremors. This was Japan's worst earthquake in the 20th century after the Great Kantō earthquake in 1923, which claimed more than 105,000 lives. Most of the largest earthquakes in Japan are caused by subduction of the Philippine Sea Plate or Pacific Plate, with mechanisms that involve either energy released within the subducting plate or the accumulation and sudden release of stress in the overlying plate. Earthquakes of these types are especially frequent in the coastal regions
Sagami Trough because of the proximity to a population center (with over 36 million living in Tokyo's metro area, with a total of 43 million living in the Kanto Region) and the magnitude the Sagami Trough can create. The Sagami Trough megathrust generated the 1703 Genroku earthquake, which was the greatest rupture along the trough in the last thousand years, and the 1855 (Ansei) and 1923 (Great Kanto or Taisho) earthquakes. Sagami Trough The also Sagami Trench, Sagami Megathrust, or Sagami Subduction Zone is a long trough, which is the surface expression of the convergent plate boundary where the Philippine Sea Plate