[Geysers] Fan and Mortar history

Michael Goldberg goldbeml at ucmail.uc.edu
Sat Dec 17 20:18:39 PST 2011

Between the season-ending reports that Fan and Mortar looked "broken" and 
the lack of washed markers to start the winter, I have a sinking feeling 
that they've gone dormant for the time being.

I've cobbled together an incomplete history of F&M active phases over the 
past 25 years.  Some of it is personal recollection.  Where possible I 
have corroborated (or corrected) it using the OFVC logbook data posted 
on GOSA's website.

Dormant 1985-86?
Active 1987-88
Dormant or very infrequent 1989  (early issues of the Sput would know)
Active 1990-94
Dormant 1995-June 1996
Active June 1996-May 1998
Dormant May 1998-July 2000
Active July 2000-August 2005
Dormant August 2005-June 2007
Active June 2007-October 2011

In many of the active years, there is a seasonal period of longer 
intervals (sometimes over a month) during the spring high water.
The onset of actual dormancy appears to come at any time, often without 
warning (2005 is a good example).

On the flip side, once eruptions resume the intervals might drop right 
away to their normal range.  Let's hope that happens again soon.

Michael Goldberg
michael.goldberg at uc.edu

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