NOAA Teacher at Sea
Aboard NOAA Ship Fairweather
August 6 – 23, 2018
Mission: Arctic Access Hydrographic Survey
Geographic Area of Cruise: Point Hope, northwest Alaska
Date: August 22, 2018
Weather Data from the Bridge
Latitude 55 44 N
Longitude – 165 23.04 W
Air temperature: 8 C
Dry bulb 8 C
Wet bulb 8 C
Visibility: 0 Nautical Miles
Wind speed: 9 knots
Wind direction: east
Barometer: 1008.4 millibars
Cloud Height: 0 K feet
Waves: 1 feet
Sunrise: 7:10 am
Sunset: 11:01 pm
Science and Technology
There are other data being collected besides ocean floor mapping using the Bottom sampler. Ocean floor samples are collected at many positions along the track line.
This is quite a gizmo, at the end is a metal scoop that collects soil samples once it hits the ocean floor. On both sides of the pole near my right hand, there is two underwater lights that is activated prior to deployment and a GoPro placed in a waterproof compartment. The camera is operated from a wireless connection and the remote control device is attached by Velcro to your wrist, just like a watch. The device weighs around 35 pounds.
Once the sample is retracted and emptied on the deck, the size of the aggregate is measured using a scale and recorded. Why is this information useful ? This data will be used used by mariners when assessing the best place to deploy an anchor. An ocean bottom containing a muddy composition is preferred as it helps to keep in place both the anchor and chain. Below is a sample we retrieved off of Point Hope, Alaska. Using the bottom sample below, what are your thoughts, is this an ideal located to drop anchor?
Dropping an anchor for a ship is not a 5 minute job. I recall fishing with my cousin in his small boat when I was in elementary school; we would arrive at an ideal location to catch lake bass and toss our anchor overboard. It was nothing fancy, a large plastic bucket filled with sand. With the rope attached, we lowered the bucket “anchor” tie it off with some slack and for the most part it kept us from moving. Anchoring a large 1,500 ton ship requires around 30 minutes to secure and the ocean depth would determine the amount of chain to use. The anchor weighs 3,000 lbs and 400 – 700 feet of chain is deployed; this depends on the ocean depth. This brings the total weight of anchor and chain to around 48,000 pounds. The anchor itself does not secure the ship, it is the combined weight of the chain and anchor. After the chain is deployed, officers monitor the ships movement to ensure the anchor is not dragging using ECDIS, which uses a GPS feed that tracks the ship’s movement. Interesting fact, the Fairweather can hold 100,000 gallons of fuel, for ship stability purposes the fuel supply never gets below 40,000 gallons.
During the past few days, the sea has been a bit rough, but I love it especially at night, falling asleep is so much easier. It looks like Wednesday, I will be deploying the drifter buoy, stay tuned there will be an entire blog dedicated to it, including how to login and track its movement!. So far on this cruise I have not been able to view the constellations at night, the big obstacle is the fog. Remember, the sun sets at around 11:30 pm and because of our latitude, it does not get very dark at night. The other big issue has been the weather the past few days, mostly overcast and fog. As we transit to Kodiak Island, the weather forecast does not mention much about the sun, though we are in Alaska on the water!
Something else interesting to note; recall a few blogs ago I discussed relative humidity as a comfort gauge? It is the dew point temperature that meteorologist use for predicting rainfall, if the dew point temperature is 75 and the air temp is 76 F near the surface rain is almost guaranteed. Cruising in the Unga Strait within the Aleutian Islands today, the cloud deck is roughly currently at 1,000 feet. It is at that location where the dew point and air temperature match and cloud formation begins. This is what we call the LCL, lifting condensation level.
Last night I was talked into played the bass guitar for the first time, playing with the band on board. They brought me up to par quickly, it was fun! I left the singing to the professionals, our deck hand Kyle and the XO (Executive Officer) Mike!
Until next time, happy sailing !