Presented by Gary Greene, Moss Landing Marine Labs, San Jose State University and President, Circum-Pacific Council
The Queen Charlotte transform (QC) fault system is a major structural feature that extends from near the northern end of Vancouver Island, Canada to the Fairweather Range of Alaska, where it connects to the Fairweather (FW) Fault system. The QC-FW transform marks the margin between the North America and Padific plates. Until recently the QC fault system, exclusively located in the oceanic realm, was poorly mapped but through the efforts of the USGS, Geological Survey of Canada, U. Alaska, and NOAA, the entire ca 900 km length of the fault and its immediate surrounding seafloor have been surveyed using multibeam echosounder and geophysical instruments. These data present a straight 'knife edged' fault that appears to accomodate the majority of the relative plate motion along the priary strand of the system. However, extensive deformation associated with volcanism and fluid seeps are present throughout most of the length of the system. Elongated conjugate ridges, volcanic cones, and mud volcanoes are well imaged in the bathymetry and in seismic-reflection profiles. Multiple fluid sources including thermogenic formed fluids from hydrocarbon basins are speculated. Seafloor structures and geomorphic feature formed on the seafloor from volcanism and fluid flow provide valuable habitats for various organisms that live at depth in the region.