南关东地区和东海地区,被地震预报联络会确定为加强观测区。这是因为该地区是日本社会经济活动的重要地区,而且,自古以来,经常遭受地震灾害,尤其是内陆发生的直下型地震比其他地区都多,并与沿日本海沟发生的海沟型地震(也可称为海洋性地震)一样,地震活动性较高。到目前为止,人们普遍认为,震源在陆地上的直下型地震是由于活断层所引起的。这种 South Kanto region and the East China Sea region, was contacted by the earthquake prediction will be determined to strengthen the observation area. This is because the area is an important area for Japan’s social and economic activities. Moreover, since ancient times, it has suffered frequent earthquakes, especially in the inland areas, more than any other area and has been associated with trench-type earthquakes Also known as maritime earthquakes), have higher seismicity. Until now, it has generally been assumed that the direct-type earthquakes on earth were caused by active faults. This