Hi Canie,

The man in the photo is John Rogie. He does the CO2 testing at Lake Mary. If you go back and look at the field instruments in one of those photos you'll see a red plastic box on the left side. Take a second look, its attached to a teflon frying pan and inside the pan is a fan. That was his first instrument he created to measure CO2 at 90 places at Lake Mary.

I too got the lecture when I was on the volcanic tour of Mammoth Lakes with Charles Watson and other friends. John Rogie gave us a very nice lecture as well as David Hill the Chief of the USGS in the Western Region and retired seismologist Roy Bailey.

I'm attaching John Rogie's homepage so you can have a look. It has the same picture that was in your attachment.

Petra

• John Rogie's Home Page