Puget Sound Convergence Zone of the beginnings of the University District and the University of Washington community. Just north of Roosevelt High School, an inch of snow coated the ground, and due west of the school in the Green Lake neighborhood of Seattle, an inch of snow had also fallen. In line with the known "abrupt edge" of the Puget Sound Convergence Zone, areas to the south of this Green Lake-to-Roosevelt High line (marked by NE 68th Street), including the U-District, witnessed only a dusting of snow. Puget Sound Convergence Zone The Puget Sound Convergence Zone (PSCZ) is a meteorological phenomenon that occurs over
Puget Sound faults geologic province is the approximately 50 million year (Ma) old marine basalts of the Crescent Formation, part of the Siletzia terrane that underlies western Washington and Oregon. East of Puget Sound the basement of the Cascades province is various pre-Tertiary (older than 65 Ma) metamorphic rock. Somewhere between Puget Sound and Cascades foothills these two geological provinces come into contact. As the juxtaposition of various disparate tectonic structures in northwest Washington requires significant strike-slip movement, it is further expected that this contact will be a major fault. The northern end of the Crescent Formation (aka Metchosin Formation) has been identified