The tsunami source of the 2016 Fukushima Earthquake, which was generated by a normal faulting earthquake mechanism, is estimated by inverting the tsunami waveforms that were recorded by seven tide gauge stations and two wave gauge stations along the north Pacific coast of Japan.
The debris differs from ordinary demolition waste or normal earthquake rubble because a lot of it is soaked in seawater that roared inland.
On November 21, 2016 (20:59:49.270 UTC), according to the US Geological Survey (USGS), a normal fault earthquake occurred off the coast of Fukushima, northeast of the Japan Coast.
We also found a normal fault earthquake between strike-slip fault events beneath the western Sea of Marmara, which also indicates the existence of a segment boundary of the North Anatolian fault at the source location.
The 1933 Sanriku earthquake was a normal-faulting earthquake in the Pacific plate beneath the Japan Trench (Kanamori, 1971), located north of the Mw 7.6 aftershock of 2011.
In the case of the great earthquake doublet along the central Kuril trench in 2006, an interplate earthquake of Mw 8.3 was followed by a normal-fault earthquake of Mw 8.1 about 2 months later (Ammon et al., 2008).
They concluded that the 2011 Tohoku earthquake, in combination with a preexisting normal-faulting stress regime, triggered a normal-faulting earthquake sequence.
All of the earthquakes mentioned above were thrust-type earthquakes at the plate boundary; except the outer-rise aftershock, which was a normal-type earthquake occurring at the outer swell of the Japan trench.
The second largest aftershock (Mw 7.6), which was a normal-faulting earthquake and was a bending-stress intra-plate event caused by the strain reduction on the subduction thrust, occurred at the outer rise of the Japan Trench and was well relocated with its aftershocks.
Other non-thrust type earthquakes included a large intraslab earthquake (M 7.1, April 7) and a normal faulting shallow earthquake (M 6.5, March 28) followed by their own aftershocks.
