St. Lazaria is a basalt island just off of Kruzof Island. It is easy to see columns of basalt going in various directions. The formation pictured here tops out well above the high tide line, but is no doubt kept clear of vegetation by the pounding it receives from storm waves where it is situated on the side of the island facing the Gulf of Alaska.
I’ve been told that St. Lazaria was formed marginal (or under?) ice during the ice age before last, and that it was possible to tell this because of the way the basalt looks. However, it’s not entirely clear to me what characteristics are indicative. Perhaps it’s the nature (and orientation) of the basalt columns?
Questions:
- What would it be like to sit at the top of one of the ocean facing cliffs during a big winter storm?
- How quickly do the ocean waves erode the basalt?
- Is weathering/erosion enhanced by living things that colonize the rock?