Mt Lassen Hot Rock mystery (episode 3)
While waiting for back-ups to complete then Illustrator to install, i researched the “hot rock” mystery and uploaded a scanned in section of the USGS document: “Maps showing thermal features and topography of Devils Kitchen and Bumpass Hell, Lassen Volcanic National Park, California” to Map Warper.
What exactly do i mean by the “hot rock” mystery?
Lassen Volcanic National Park has two locations that explicitly focus on the effects of the eruption in the 1915. One spot is the Devastated Area interpretive trail, another is the “Hot Rock” pull off. In both places, visitors may read about the photographs BF Loomis took which documented the effects of the eruption. References are made to the black dacite rocks in contrast to the pink and grey dacite: the black dacite is the recent rock formed by the lava that was cooling in 1915. The pink and grey dacite make much of the peak of Lassen and were washed down in the mudflow along with the new black dacite.
Loomis photographed and noted the “hot rock” and there is the “hot rock” at the pull over and the “hot rock” at the interpretive trail. Christine and i became a little confused as we tried to figure out how the “hot rock” could be in two places at once. In fact, and with no shock, there are two different boulders in the “hot rock” photographs.
The smaller hot rock is documented multiple times by Loomis, as in the pair of images reproduced by the USGS: one from May 22, 1915 and the same scene taken by Loomis later that summer. Another USGS page offers the single “hot rock” photo with an 1984 comparison image. (I found a note here which asserts the hot rock “later disintegrated.”)
This “hot rock” is in the Devastated Area.
Both the pull-over and the Devastated Area have a Loomis image of a group standing before a stone with the annotation of “hot rock” of the dimensions of the stone This postcard is a reproduction of the group portrait, too small to see the expressions on the faces which Christine studied in the large reproduction in the park. Note that Lassen has no steam from the top.
References after the cut.Timeline research:
http://www.msss.com/earth/lassen/lassen2.html
http://vulcan.wr.usgs.gov/Volcanoes/Lassen/EruptiveHistory/eruptive_activity_1914.html
http://www.uwsp.edu/geo/projects/geoweb/participants/Dutch/VTrips/Lassen.HTM
USGS fact sheet: Volcano Hazards of the Lassen Volcanic National Park Area, California
Just photos:
- USGS map: Geologic Map of the Lassen Peak, Chaos Crags, and Upper Hat Creek Area, California
Note that the website has the May 22, 1915 single “hot rock” photo and the same scene taken by Loomis later that summer. - The single “hot rock” photo with an 1984 comparison image.
- http://geology.cwru.edu/~huwig/catalog/volcanoes.html#lassen%20peak Note that this shows the single “hot rock” and asserts it “later disintegrated.”
- Lantern slides from Berkeley: includes the car series and the single “hot rock” with the hat.
- This postcard is the image of the “hot rock” group portrait. Note that Lassen has no steam from the top.
- NPS photography collection
