[Geysers] Geyser Report: Fan & Mortar, August 5 @ 2116

[Tara Cross]

A message from Tara Cross <fanandmortar at hotmail.com>

Fan and Mortar erupted at 2116 on August 5 for an interval of 3d 5h 19m.

The pattern of event cycles whas somewhat different during this interval.  
At first they were normal, but then starting on the evening of the 4th, 
intervals between events shortened to 2-3 hours.  First water in Main Vent 
was seen at 1709, 1925, and 2208, and then 0110 and 0410 on the 5th.  That 
made for a frustrating, sleepless night for the gazers who were observing 
F&M during the nighttime hours.

During the early morning event cycle, we were encouraged by a triple pause 
with plenty of splashing in Main Vent.  Then High Vent went into lock-like 
behavior 15 minutes after River Vent started.  However, the water level 
completely dropped out of Gold Vent and after 5 minutes it dropped out of 
lock-like behavior.  Water levels plummeted shortly thereafter.  Needless to 
say, we were rather grumpy after that.

Following this cycle, nothing was seen until Main Vent splashing was seen at 
1507, leading to a strange event cycle.  River Vent was on for a full 20 
minutes before turning off for a 6-minute single River pause.  After that, 
it seemed that the system was trying to have a Gold pause, and that killed 
the water levels in Gold.

We were beginning to lose hope for an eruption in daylight when Main Vent 
began to huff as the sun began to set.  Events took place as follows:

2000 River Vent on
2005 River Vent off (River pause)
2007 Main Vent splash
2016 River Vent on
2028 River Vent off (River pause)
2037 Bottom Vent (d=6m40s)
2044 Bottom Vent (d=1m10s)
2045 Bottom Vent (d=50s)
2050 River Vent on
2051 ENORMOUS Main Vent splash that filled the entire vent
2052 Bottom Vent (d=30s)
2054 Gold Vent on
2056 Angle Vent on
2107 High Vent in lock
2110 High Vent falls out of lock
2111 High Vent builds back into lock, eventually joined by Gold; Angle Vent 
also went into steam phase
2116 FAN AND MORTAR

The eruption was initiated by Main Vent, followed by East and the rest of 
the Vents.  Once again, Mortar quit approximately 45 seconds into the 
eruption and remained quiet for several minutes.  The eruption was Mortar 
dominated, though Fan had several nice surges.

Considering that the sun had already set, the viewing conditions for this 
eruption were astonishingly good.  Every Vent could be seen clearly, backlit 
by the dusk in the western sky.  Sometimes I am in awe of the sheer power of 
Fan & Mortar; other times I am busy getting as soaked as I can.  This time, 
I just sat back and said "Wow."

A very BIG thank you to everyone who put in time waiting for Fan & Mortar 
during this interval.

--Tara Cross
fanandmortar at hotmail.com