Hopefully I’m not the only one who found this fascinating… But it’s a nice detour from meetings and sidewalks and politics that’s still very local. Maple Leaf Life has a very fun post on our local geology. Obviously they’re discussing Maple Leaf specifically but the full USGS map they link to covers a much larger portion of North Seattle and Shoreline.
There’s a lot of fun stuff here including the Wetland deposits (Helocene) right in the middle of Pinehurst. It seems to fall between Roosevelt Way NE, 12th Ave NE, NE 124th St, and NE 117th St. My favorite part has to do with the mention of Thornton Creek which Maple Leafe Life also highlighted:
Within the boundaries of the map area are two large urban lakes, including the most heavily visited park in the State of Washington (Green Lake Park); a stream (Thornton Creek) that still hosts anadromous salmon despite having its headwaters in a golfcourse and a shopping center …
There’s a lot more there which I haven’t read yet but if there are any geology buffs in the neighborhood, let me know what you find.
Can you give us a link to the map and report. I think it’s interesting but couldn’t tell anything from the map shown.
Thanks, Vicki
Regarding the bit in the article about Thornton Creek Watershed, several primary problems affect the creek health:
>The developed uplands (in other words, the neighborhoods and the mall) generate large, peak stormflow runoff that changes the shape and nature of the creek channel.
>The water quality is poor because of runoff from roads and use of yard chemicals. Even washing one’s car pollutes the creek.
>Encroachment into the floodway and channel migration zone for the creek by roads, sewer lines, and houses. The creek doesn’t have room to be a creek.
>Loss of shade along portions of the creek because of loss of forest cover resulting from roads and yards.
If you want to know more about the Thornton Creek Watershed, see http://www.ci.seattle.wa.us/util/About_SPU/Drainage_&_Sewer_System/Reports/Thornton_Watershed_Report/index.asp. This info is in there.
You can probably also find such reports on Piper’s, Longfellows, Schmidts, and Taylor Watersheds online.
The one I already linked to seems to be down right now… http://pubs.usgs.gov/sim/3065/