  We present the results of a response of global seismicity to St. Patrick's
Day (March 17) geomagnetic storms in 2013 and 2015, which occurred during
rather similar solar flux levels and nearly identical storm sudden commencement
times. A similar pattern of most substantial earthquake occurrence after storms
is revealed. Namely, with a time delay of ~30 and ~39 days after storm onsets
in 2013 and 2015, respectively, the strong crust earthquakes occurred at
continental areas in Iran (M7.7, April 16, 2013) and Nepal (M7.8, April 25,
2015). Then, with a time delay of ~68 and ~74 days after storm onsets in 2013
and 2015, respectively, the strong deep-focused earthquakes occurred beneath
the Sea of Okhotsk (M8.3, May 24, 2013, Russia) and beneath the Pacific Ocean
(M7.8, May 30, 2015, Japan). It is shown that in the time of geomagnetic storm
onsets (06:04 UT in 2013 and 04:48 UT in 2015), the longitudes at which the
future strong earthquakes occurred were located under the polar cusps where the
solar wind plasma would have direct access to the Earth's environment. The
results support our earlier findings [Ouzounov and Khachikyan, 2022] that
seismic activity may respond to geomagnetic storm onset with a time delay of up
to ~ two months.
