Saturday, March 31, 2018
Thursday, March 22, 2018
Comparing Lidar of Different Years at Dynamic Landscapes
The Washington State DNR has recently uploaded more lidar coverage (http://lidarportal.dnr.wa.gov/). Some of the recent uploads are of lidar that was flown in the early 2000s such as Jefferson County, but there is also some 2017 high resolution lidar that has been a bit of distraction to geomorphologist.
With multiple year available on the portal, there is also the opportunity to do comparisons at sites that have undergone change. Alluvial fans can be a good place to see significant changes.
Canyon Lakes Creek alluvial fan has been going through significant recent changes. The fan is in part controlled by the meanders of the Middle Fork Nooksack River as well as human infrastructure.
2006 lidar
The change in flow on the fan has eroded into an old elevated terrace.
2013 lidar
The results have been significant property damage as the creek erodes new channels and flows and floods into areas not previously near the creek.
2006 lidar
2013 lidar, note the channel has been entirely filled
The lumpy ground west of the lower reach of Racehorse Creek is a very large landslide deposit that dwarfs the event that took place in Racehorse Creek. The slide extended across the Nooksack River Valley. The age of this slide is not currently known.
Racehorse Slide
A comparison between 2006 and 2017 lidar shows the 2009 slide before and after.
2006 lidar
2017 lidar
The slides are on dip slope of a sandstone unit within the Chuckanut Formation.The 2009 slide is readily visible from the Nooksack Valley south of Kendal and appears as a sharp edged block missing from the the slope. The lidar suggests that the slip was off the same bed of the formation.
Dave Tucker as a field trip write up on the slide fieldtrips/the-chuckanut-formation/field-trip-to-the-2009-racehorse-creek-rock-slide/.
Saturday, March 17, 2018
Old Shipwreck in Drayton Harbor
Doing a bit of pre field excursion research I noted a shipwreck along the shore of Drayton Harbor in northwest Washington.
The map was from 1972. An earlier 1950s map did not show the wreck. The wreck was not part of my purpose and I forgot about until we came across its remains.
It was remarkable sunny clear late winter day. Frost in the morning then sun warming things to about 50. Drayton Harbor is a shallow bay abutting the City of Blaine near the Canadian border. Cleanup efforts that have been really slow and challenging have slowly returned the bay to healthy enough conditions for growing oysters.
The BC Coast Range is the predominant Mountain view.
But the view of Mount Baker is equally nice on a clear day.
Labels:
history,
odds and ends
Location:
Drayton Harbor, Washington, USA
Wednesday, March 14, 2018
Haematopus bachmani, Black Oystercatcher
Black Oystercatchers fall into the category of really easy to remember shore birds. There are so many others that are harder to distinguish for beginners or once distinguished their names get lost to memory. It takes work and review to stay up with shorebirds. But oystercatchers are easy.
I spotted this pair sunning themselves on the rocky spit south of Kala Point south of Port Townsend. I felt a bit bad disrupting their rest. So I headed up onto the upper spit and hid behind the large driftwood logs to get a around them. By the time I got even with them they were back at work seeking mussels.
Thursday, March 8, 2018
Northwest Washington Iconic Mountain View
I have been fortunate to live in areas where mountains of some sort are always on the horizon. The iconic mountain of northwest Washington is Mount Baker.
After days of clouds and rain (and some snow) we had a brief clear spell and Mount Baker welcomed me home when I headed onto the Samish Flats. After a month of heavy snow the 10,000 foot volcano mountain along with its earlier predecessor Black Buttes, an earlier eruptive center, and the sharp peaks of the Twin Sisters were heavily plastered in white. The high peaks were aglow in the last sunset rays of the day above the lower Northwest Cascade and Chuckanut ridges.
Saturday, March 3, 2018
Foulweather Bluff Adams Apple and Track of Tornado
Foulweather Bluff is at the north end of Kitsap County. To the west of the bluff is the entrance to Hood Canal, a long inlet that extends far to the south. To the east is the continuation of Admiralty Inlet and Puget Sound.
The peninsula has an outline that suggests a head with an open mouth. I was looking into the geology of the estuary on the neck of Foulweather via the T Sheet (one of the earliest surveys) map of the area. A small hand written note next to the estuary indicates that either the mapper or someone using the map afterwards saw the peninsula as a head as well.
Click to blow up image to read the hand written notes
In addition to the "Adams Apple" note, there is a note north of the estuary stating "Track of Tornado". Some of the early T-Sheet maps emphasized a survey of the timber stands. I am skeptical that a tornado passed across the peninsula as tornadoes are very rare in western Washington; however, concentrated intense wind events do happen and it appears that a large timber blow down had taken place prior to the survey.
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