We were graced with the presence of Jon Riedel, North Cascades National Park Geologist/Glaciologist. Some of the fun facts we learned were:
- Lake Chelan is 1500 feet deep with 1700' of glacial sediment below that, meaning that the glaciers carved out nearly 3200' of relief in this lake.
- 30,000 years ago, the big beaver glacier flowed out into ross lake blocking the skagit river, causing it to flow north and out into the Fraser River.
- The technical term for kitty litter rock is grus, which is weathered granite
- NOCA (north cascades national park) has had a 50% decline in glaciers in the last 100 years.
- Thunder Creek (literally, right up the road from the ELC) is the most glaciated watershed in the continental US. 13% of the water flowing into the creek is 13%, while 35-40% of runoff in the summer months come from these glaciers.
- Bad news, streamflow in the thunder creek drainage has decreased nearly 30% in the past 100 years, which can be attributed to the shrinking glaciers
- The skagit watershed has 2.1% glaciation.
- This same watershed has lost over 400 billion gallons of water flow in the last 17 years due to diminishing glaciers.
Here are some photos of the day with Jon.
pointing out some glacial erratics we found along the trail side
View of the dormant Skagit Fault. Jon believes this fault is what caused the pickets to the north, and then forbidden/eldorado & etc to the south. Look at a map and draw a line, it totally makes sense
Jon pointing out to the group the skagit fault line
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