[S-CG59] 地殻流体と地殻変動

[SCG59-P05] 宝塚観測点における20年間の地震にともなう地下水位の変化

*松本 則夫¹、木口 努¹ (1.産業技術総合研究所地質調査総合センター地震地下水研究グループ)

キーワード：地震に伴う地下水位変化、宝塚観測点

We observed eight postseismic increases in groundwater pressure were observed at Takarazuka observatory (TKZ) in the last two decades. Shapes of the curves in the three largest increases are relatively similar: it might be same mechanism for the postseismic increases. Recovery test shows that the postseismic increases may not be caused by sudden increase of pore pressure near the TKZ well. We compare postseismic changes at TKZ with the postseismic changes in groundwater level at four observatories which are inconsistent with poroelastic theory. The threshold of earthquakes with postseismic changes in groundwater level at TKZ locates more upper-left side than the previous results of other observatories in the Magnitude - Distance plot.