The Tofino cluster is named for the village of Tofino on the west coast
of Vancouver Island, Canada. As with many calibrated clusters along
coastlines, azimuthal coverage is a major problem, ameliorated somewhat
in this case by the availability of obervations for some events from
ocean bottom seismometers. About half the events in the cluster are
observed only to regional distances but they are retained to provide a
sufficient number of local-distance readings to adequately constrain the
crustal velocity structure and depth constraint. Similarly, about half
the events are beneath the Moho (30 km) of the crustal model, to a
maximum depth of 45-50 km. Even though there are only two events with
magnitude 5.0 or greater (the largest is 5.7) the cluster does have
reasonable coverage at teleseismic distances. All events have depth
control from near-source or local-distance observations, and a few also
have teleseismic depth phases for corroboration.
