G16K (REMOVED)

Station Notes

Station Close-Out Report
Known bear activity at site
- Bear pulled out conduit and damaged sensor cable within 10 days of station installation

Service Plan

Site Access

Helicopter
Loose, fine soil at the surface can be problematic during take-offs and landings

Site Contact

No site contact

Site Visits

2021_05_31 Removal (R. Bierma, K. Schroeder)
USArray Station Removal Report Form V1.5
STATION CODE: TA.G16K
STATION LOCALE DESCRIPTION: Koyuk River, AK
STATION REMOVAL LOG DATE (UTC): 5/31/21
STATION/SENSOR DOWN TIME (UTC): 19:09
REMOVAL DESCRIPTION: Sensor removed, borehole casing cutoff and capped, hut removed.

ACTIONS TAKEN: Powered the station down after collecting a final screenshot. Sensor issued "remove" command using Willard. Orientation was taken and sensor removed. The metal casing was cut off 9” below grade using a die grinder and capped with a 6" expansion end plug. The remaining hole was filled with local dirt and rock.
The hut was packed with the conduit, well cap, casing cut off, hut antenna mount and any other site debris.
CASING CONDITIONS: The casing was in good condition with no damage to the wellcap. No evidence of frost jacking. Previous methods of securing the conduit to the side of the hut using brackets seemed to work well. There was evidence of bear activity at the site since our last visit, but the conduit was fine.
SEISMOMETER REMOVAL: 2/3 difficulty.
The jack was used to break sand tension, the jacking required moderate force. No water or ice down hole. This sensor had been swapped in 2020, so was only recently bedded. The force required to break the tension was unexpected.

LAT/LONG OF SENSOR HOLE: N 65.39359, W -162.35474, WAAS enabled
Distance and azimuth to Hut from Sensor hole: 124", 345.620 degrees
Wind turbine: [not present]
Bottom of wellcap to grade level: 5”

SENSOR ORIENTATION MEASUREMENTS:
Measured with Octans Unit: b/c 5008931, s/n 34531211
Measured with rods on pin: Yes
Casing/wellcap marked with reference orientation: No

SENSOR ORIENTATION: 0.00 degrees
Sensor orientation from install: 0.00 degrees

COMMENTS: Soil temperature sensor was removed. Data loggers labeled and collected for later download.
Vaisala still had active connection to EP
STS5Field would not connect with the sensor after multiple attempts, so the removal command was issued using Willard.

REMOVED:

Q330 TagId – 2110; bc – 5005882
Baler 44 sn – 13484; bc – 5008404
STS5A sn – 130718; bc – 5014972
VIE bc – 5009091
QEP sn – 116861; bc – 5001174
infra SETRA sn – 5281764; bc – 5013976
infra NCPA sn – H112080439; bc – 5012253
Regulator Board sn – 499; bc – 5010373
BGAN Modem sn – 353938030188407; bc – 5018307
BGAN SIM sn – 898709914412612047
XI202 sn 694; bc – 5018216
WXT536 sn – N4010170; bc – 5018766
Power sys 1.6.4
Charge Controller bc – 5016812
LiFePO4 sn – 5452; bc – 5017619
LiFePO4 sn – 5603; bc – 5017653
LiFePO4 sn – 5604; bc – 5017654
LiFePO4 sn – 5607; bc – 5017657
LiFePO4 sn – 5608; bc – 5017658
LiFePO4 sn – 5689; bc – 5017725

DAMAGE: None

LEFT AT SITE: cutoff casing with cap

VISITORS:
1. Bierma
2. Schroeder (Recon)
3. Pahl (Alpine)
4. Potgieter (Alpine)
2020_08_10 Service (R. Bierma, J. Miner)
USArray Station Service Report
Form V1.0

STATION CODE:
TA.G16K

STATION Locale Description:
Koyuk River, Alaska

STATION SERVICE LOG DATE:
20200810

STATION/SENSOR DOWN TIME (UTC):
Station offline for ~45 minutes, 15:15 for sensor swap

SERVICE DESCRIPTION:
Trouble shoot sensor issues, swap as necessary. Upgrade CC firmware and collect Baler media. Check BGAN antenna cable.
UPON ARRIVAL:
Station in fair condition, a bear had damaged the sensor cable after separating the conduit from the well cap. Some water remained in the casing. The BGAN signal was on narrow beam, with a signal strength of 65.
ACTIONS TAKEN:
Baled the water out of the casing. Existing STS5A was oriented to 2.2 degrees. Locked the sensor and pulled it from the casing using a scissor jack. Added a liter of dry sand to the bottom once the water had been removed. New TOC to sand depth is 87". Installed new STS5A and oriented with the Octans to 360.0 degrees. Updated CC firmware to 1.20 and swapped out the station baler media.
Secured a makeshift conduit retainer on the casing to attempt to prevent future sensor cable damage.
Verified the station configuration.
Baler media swap.

EQUIPMENT REMOVED:
STS5-A sn - 130819
STS5-A bc - 5015637

EQUIPMENT INSTALLED:
STS5-A sn - 130718
STS5-A bc - 5014972

COMMENTS:
No other noteworthy issues or obvious sign of corrosion on the BGAN cable.
Door locked and taped prior to departure.

VISITOR:
1. Bierma
2. Miner
3. Bue (Alpine Air)
ON NEXT VISIT:
n/a
CHANGES AFFECT INSTRUMENT RESPONSE:
n/a
2019_05_14 Service (J. Miner, D. Bloomquist)
USArray Station Service Report
Form V1.0
STATION CODE:
TA.G16K
STATION Locale Description:
Koyuk River, AK, US
STATION SERVICE LOG DATE:
20190514
STATION/SENSOR DOWN TIME (UTC):
2130-2314
SERVICE DESCRIPTION:
Planned aerial recon while traveling between G15K and F17K
UPON ARRIVAL:
Station had clearly been revisited by a bear, the well cap was ripped off, not pulled off, the fiberglass was torn off of the remainder of the well cap. The conduit was pulled out. The cable had clear bite marks, but not that compromised the cable function. The top stuff sack had been removed and eviscerated. The casing was full of ice and snow. Fresh bear tracks were at the station but the damage likely occurred earlier in the spring or fall based on the snow and ice accumulation.
ACTIONS TAKEN:
The team attempted to remove the snow and ice with the tools available but were unable to get past the second stuff sack which was frozen into the casing and beyond reach. We were unable to remove the casing to replace the sensor cable so we pulled the other end through and replaced the conduit instead. The conduit was secured to the hut with a saddle clamp and a pipe clamp attached to hose clamps. Additionally the casing side was also attached with pipe clamps attached to hose clamps.
The well cap was replaced with a spare. However, if the bear is equally determined the well cap doesn't stand a chance. The station equipment was checked and was otherwise intact.
EQUIPMENT REMOVED:
NA
EQUIPMENT INSTALLED:
NA
COMMENTS:
The station was otherwise in good condition. The door tape was chewed through but no water had leaked into the hut. The bear(s) in this area are truly bored and this station will likely be revisited in the near future based on the past events.
VISITORS:
Jeremy Miner
Doug Bloomquist
Turner Pahl (Alpine Air)

ON NEXT VISIT:
Bring equipment to melt and remove snow/ice in the casing. May need to bring spare sensor cable to replace the damaged cable. Expect bear damage.
CHANGES AFFECT INSTRUMENT RESPONSE:
NA
2018_05_22 Service (J. Miner, M. Enders)
2017_07_30 Service (D. Bloomquist, K. Aderhold)
2017_07_15 Install (J. Miner, K. Aderhold, D. Bloomquist, M. Enders)