Figure 8.
hours of observing time will be awarded to
FT programs on each telescope each month.
Hurricanes Kilo,
Ignacio and Jimena
(left to right) in the
Hawaiian environment,
characteristic of the
active Central Pacific
hurricane season of
2015. Image from
Maunakea Weather
Center, obtained on
August 29, 2015.
Yet More Weather
Both Gemini North and Gemini South were
closed by midyear snow. In the north Central
Pacific, Hawai’i was like the target in a shooting gallery, as hurricane season generated
more than 10 named storms to date (Figure
8). Thankfully, there were no direct hits, but
significant side effects included long periods
of fog and precipitation at the summit, not
to mention a fairly continual stream of flash
flood warnings at sea level.
Figure 9.
In August, Southern Hemisphere winter
weather at Cerro Pachón deposited large
amounts of snow and ice on the summit, forcing an evacuation; as a precaution, Gemini
South switched to generator power that day.
After several more days of bad weather, copious amounts of snow continued to accumulate on the access roads and the summit itself.
When the storms abated, hard work by AURA
Shared Services cleared the roads and allowed observers and crew to get back to
the telescope after a week (Figure 9). By that
time, however, almost all of the observatory’s
fuel had been consumed; and without the
possibility of getting a fuel truck to the site,
there was no alternative but to completely
shut-down all systems.
Excellent teamwork between the engineering groups allowed for a quick and safe
switch off of all equipment. Last to be shut
down was, of course, the generator, with just
10 hours of fuel remaining! In total, the observatory ran on generator power for over
nine days, consuming almost 15,000 liters
of diesel fuel. The following week, with assistance of the grader and motor digger, a fuel
truck made it to the site, all systems were restarted, and normal operations resumed.
All in all, Gemini South was closed for more
than two weeks, a rare occasion in recent
January 2016
Snow clearing after winter
storm at Cerro Pachón.
times and not good for our observing statistics. However, the great amounts of snow
melt water did a lot of good for the region,
and despite some local damage, was gratefully received.
Gemini South and the Chilean
Earthquake
As you’re probably aware, Gemini South was
affected by the large (magnitude 8.4) earthquake which struck Chile on September 16th.
At the time of the quake, Gemini South was
closed due to sever weather (see news item
above). Since systems were powered up, the
2015 Year in Review
GeminiFocus
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