Post-conference Field Trip around Yellowstone National Park (No.1)

 The conference of the International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI) was held in Portland, Oregon, USA. After attending the IAVCEI 2017 conference, I joined the field trip of the Yellowstone Volcano. It was one of the post-conference field trips, and so the guides were volcanologists, geophysicist and geochemist. And so the field trip itself was very interesting for me.

Landslide slope of the 1959 Hebgen Lake Earthquake at the west Yellowstone.

The field trip started from Bozemand, Montana and we drove southward to the Yellowstone. We could see the Galletin Range and Madison Range from our car. Then, the first geological stop was just next to the Hebgen Lake (the west of the Yellowstone National Park) where there was a big earthquake felt in 1959. We could see the fault which moved when the earthquake occurred and the landslide slopes. There is "Quake Lake Visitor Center" now. We saw some huge rocks which fell down at that time. Also, the lake surface moved up and down...the seiche occurred. I learned a word "seiche" here. For us, Japanese, we same lake Tsunemi. Interestingly, the epicenter of the earthquake must have been inside the Yellowstonem and it was not around the Hebgen Lake.
 Then, we went into the Yellowstone National Park. I was surprised that there was a traffic jam before entering the national park. I went to the Hawai'i Volcano National Park several times, but I have never seen the traffic jam around the entrance of the national park. 

Norris Geyser Basin

Hot Springs in the Norris Geyser Basin

 The most attractive stop on the day 1 was Norris Geyser Basin. It was beautiful place with many hot springs and some geysers. The color of the hot springs varies with the temperature and the kinds of bacteria. The hot spring water was neutral to alkaline and there was a lot of SiO2 make the white color of this area. 
　

Tuff Cliff of Lava Creek Tuff Member A

 The final stop of the day 1 was Tuff Cliff of Lava Creek Tuff. It is a bit confusing that the name of the tuff includes "Lava". Actually Lava Creek Tuff is pyroclastic flow deposits and it consists of member A and B. This pyroclastic flow occurred 0.64Ma. Do you know the unit "Ma"? It stands for "million years ago". Therefore, the Lava Creek Tuff is formed around 640, 000 years ago. It is about 10, 000 years later than the formation of Yellowstone Caldera (0.63Ma). 
It must be continued... However, now it is difficult to finish this travel diary because I stopped it and didn't take a look of this blog for a while. Sorry... I will continue again at some point when I have a motivation to do so.