Geodetic inversions for this event are confronted with the challenge of poor azimuthal coverage of the source region and the possibility of stronger slip located further off-shore matching the data as well as lesser slip at greater depth closer to shore.
If that were to impede further off-shore exploration here, it might give an advantage to a foreign oil exporter.
The observations showed that discharge to the lake was doubled-peaked, with a peak discharge near the shore line followed by an almost (classical) exponential decrease, and a second peak further off-shore.
Pens and moorings were redesigned and replaced, leases were rejigged to be further off-shore, and a purpose-built vessel used to transport and bathe the fish in fresh water to keep amoebic gill disease at bay was purchased.
Other reports emerging from Australian Institute of Marine Science (Aims) surveys have revealed bleaching at sites along the Kimberley coast, and further off-shore at Christmas Island, Cocos Island and Seringapatam Reef.
This region is also recognized to have had a large tsunamigenic earthquake in 869 with a source area estimated to be further off-shore (Minoura et al., 2001).
The Japan Meteorological Agency (JMA) hypocenter (38.103°N, 142.861°E, depth 23.7 km) is further off-shore in the up-dip direction, and relocation using a regional 3D velocity structure by Dapeng Zhao (personnal communication, 2011) places the hypocenter even further off-shore (38.147°N, 142.915°E).
Inversions of broadband teleseismic signals vary in detail, but tend to place most seismic moment and slip further off-shore, up-dip of the hypocenter, and even extending all the way to the trench (e.g., Ammon et al., 2011).
The Tohoku event did radiate short-period energy and was strongly felt in Japan, but the source of the short-period signal appears to be concentrated down-dip (Koper et al., 2011), spatially separate from the large slip further off-shore.
