Wider gaps were locally present at some shoreline locations, where marine and terrestrial data were truncated at different shorelines. Marine and terrestrial data were merged with the naive assumption that they are measured in relation to the same vertical datum. Artifacts Lack of data makes most of the floor of the northeastern Pacific Ocean appear smooth. Some of the smoothness is real, reflecting a blanket of sediment that smothers the oceanic-ridge topography beneath it. Similarly, apparent differences in the physiography of the Washington continental slope, relative to adjoining parts of the slope, at least partly reflect differences in data quality.
Additional artifacts result from mismatches between sets of source data.
Perhaps the most obvious mismatch is at longitude 132 W, extending south from 52 N, where an abrupt change in apparent depth occurs at a source-data boundary. Abrupt northward termination at 46 N of longitudinal ridges in the Juan de Fuca Slope also reflects juxtaposition of differing data sources. Multi-beam swath bathymetry. May be purchased from Geomatics Canada. Areas of bad data along some 1 x1 block boundaries deleted.