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Seismology
In terms of earthquakes, Ruotsinpyhtää is located in
a very stable area. The magnitude of earthquakes
observed
in the area has been less than 3 on the Richter
scale. (Pohjatekniikka Oy 2007)
Groundwater
There are 13 classified groundwater catchment areas in
the Ruotsinpyhtää region; of these, three are
groundwater
catchment areas important for water supply (Petjärvi,
Kunkinkaankylä and Tesjoki). However, there are no
groundwater catchment areas important for water supply
or suitable for it in the vicinity of the nuclear power
plant location area. The nearest groundwater catchment
area, Jomalsundet (Category III), is located to the
north of Gäddbergsö approximately a kilometer from
the power plant (Figure 8-43). The area is comprised
of a narrow, well-defi ned ridge whose rock material is
stratifi ed sand and gravel formation. Even though the
total yield of the area is only satisfactory, the
groundwater
formation is locally important in terms of water
supply. Sea water can be absorbed into the area in
connection
with groundwater intake due to the permeable
shoreline. (Environmental Administration’s Map Service
2008)