Friday, April 16, 2010

Iceberg Point

There's not much beach along this spectacular stretch of rocky coast at the south end of Lopez Island, but there sure is a great view in pretty much every direction. The bluffs of Whidbey Island are seen in the east. Smith Island is southeast. Dungeness Spit and the Olympic Mountains are lost in clouds to the southwest. San Juan Island and Cattle Point are to the west, obscured by the haze of the late afternoon sun.

The metamorphic bedrock is littered with granitic boulders from Canada and furrowed with north-south grooves, both the legacy of glaciation a mere 16,000 years ago (give or take a few millenia). Sedums, lichens, and other small, but hardy, plants cling to irregularities in the rock surfaces.

Spencer Spit

This year, we wrapped up the beaches class with a trip down to Spencer Spit. We really didn't have enough time to do it justice, given the late hour and the logistics of folks having to catch ferries back to other islands, but still a worthwhile excursion. This place provides eroding bluffs, an elegant barrier beach, and a large salt marsh and lagoon -- all in a county better known for its rocky shorelines!

Spencer Spit reaches for rocky Frost Island, but doesn't quite get there (map view). I guess the tidal currents make it hard to close the gap. On the other hand, tombolos have formed in similar settings where the sediment must have eventually been too much for the currents to keep clear. Maybe it's just a matter of time. I suppose it's a function of the strength of the currents, the volume of sediment being delivered, and the bathymetry of the nearby area (which controls the "accommodation space" - the less space, the easier it is to fill it).

The last time I was here was shortly after the February, 2006, storm:
Spencer Spit, March 2006