Meg Stewart: Aleutian Islands, Bald Eagles, Wildflowers, and Bunkers, July 8, 2019

NOAA Teacher at Sea

Meg Stewart

Aboard NOAA Ship Fairweather

July 8 – 19, 2019


Mission: Cape Newenham Hydrographic Survey

Geographic Area of Cruise: Aleutian Islands, Bering Sea

Date: July 8, 2019

Weather Data from the Bridge
Latitude: 54° 59.104 N
Longitude: 166° 28.938 W
Wind: 21 knots SE
Barometer: 1006.6 mb
Visibility: 10 nautical miles
Temperature: 53° F or 11.5° C
Weather: Partly cloudy, no precipitation

Science and Technology Log

Today, we left the port at Dutch Harbor, Unalaska, Alaska and headed toward Cape Newenham. The mission for the Cape Newenham project is to gather detailed ocean depth data in order to knit together a comprehensive and highly detailed surface chart of the seafloor near Cape Newenham. I will talk about that process in my next post.

view of Dutch Harbor
A view of Dutch Harbor, Unalaska. The surrounding hills are volcanic, with just a thin layer of soil, and not a tree to be seen.

Dutch Harbor is a small town with a relatively deep port. The Ship Fairweather has a draft of 15.5 feet. “Draft” is the vertical length between the surface of the water and the bottom of the ship, which is called the hull. A ship’s draft determines the minimum depth of water a vessel can safely navigate and dock at a port. However, though the Fairweather has a 15.5 foot draft, the crew prefers a 20 foot depth of water at a port.

Map of Bering Sea
This overview map shows where Dutch Harbor is in relation to Alaska, the Pacific Ocean, the Aleutian Islands, the Aleutian Trench and Russia. The A-B line is shown for the cross sectional line in the next figure. Cape Newenham is out next destination.

Dutch Harbor is part of Unalaska Island, which is one of the string of Aleutian Islands. The Aleutian Islands are part of the notorious Ring of Fire that marks the edge of the Pacific tectonic plate. As the Pacific Plate moves and grinds past some plates (like along the North American Plate at the San Andreas Fault) or pulls away from other plates (like the Antarctic and Nazca plates, creating the East Pacific Ridge) or plunges beneath other plates (like the Philippine and Indian-Australian plates, where we get deep ocean depressions called the Mariana Trench and Tonga Trench, respectively), we see active volcanism (which is the “fire”) but also lots of earthquakes. The Aleutian Islands are volcanic in origin – the island chain is a volcanic arc – and are a result of oceanic crust of the Pacific Plate being subducted under the oceanic crust of the North American plate. The deep depression at this tectonic boundary – also called a subduction zone – is called the Aleutian Trench.

Aleutian Trench
Referring to the A-B line shown in the overview map above, this cross section shows the mechanics of the subduction zone at the Aleutian Trench at Unalaska Island.
Aleutian Trench tectonic map
This is a tectonic map of the Aleutian Trench area (the symbol shown as a dark black curved line indicates a subduction zone). The map shows the relative motion of the Pacific and North American plates. It is clipped from the New York State Earth Science Reference Table

Looking at a schematic drawing of the side-view, or cross section, of the Aleutian subduction zone, we can visualize what this looks like beneath the surface. The older and more dense oceanic crust of the Pacific Plate is plunging under the younger oceanic crust of the North American Plate – the more dense material sinks down or subducts – and the less dense material stays floating on top, and this process is all due to gravity. With time, as the oceanic material is drawn deeper into the subduction zone, it becomes hotter, starts to melt and then comes back up to the surface as volcanic material and a string of volcanoes forming parallel – and in this case, forming an arc – to the boundary between the Pacific Plate and the North American Plate.

Personal Log

Arriving at NOAA Ship Fairweather
Arriving at NOAA Ship Fairweather

I arrived at Dutch Harbor on July 6, after 14 hours and three legs of air travel. Fortunately, I made all my connections and my luggage arrived at the tiny Dutch Harbor airport. I was picked up by welcome smile for a nice person from the Ship Fairweather, got to the port and settled in to my stateroom. The “stateroom” is my sleeping quarters or room. I have it all to myself, it is very comfortable with a sink, a small bed, drawers and a closet to fit all my stuff, and there’s a TV that I haven’t yet figured out how to work.

My stateroom
My stateroom or sleeping quarters. Caution: panoramic photos make everything look larger than they really are.

Did You Know?

On my second day in Dutch Harbor, I went out with some new friends from the ship on a lovely hike on nearby Bunker Hill. I saw so many beautiful wildflowers along the trek and an enormous number of bald eagles. I had no idea that bald eagles would be so plentiful here, but they were everywhere. It was amazing! But the other interesting thing about this hike were the bunkers.  In June 1942, Dutch Harbor was bombed by the Japanese Navy (six months after Pearl Harbor) during World War II. At the time of the raid, Alaska was a U.S. territory, and following the bombing, the bunkers of the now-known-as Bunker Hill were built to help defend not only Alaska but the west coast of mainland U.S. And here I thought Dutch Harbor was only known for Deadliest Catch!

Quote of the Day

“Even if you never have the chance to see or touch the ocean, the ocean touches you with every breath you take, every drop of water you drink, every bite you consume. Everyone, everywhere is inextricably connected to and utterly dependent upon the existence of the sea.” Sylvia Earle

Jacquelyn Hams, July 9, 2006

NOAA Teacher at Sea
Jacquelyn Hams
Onboard NOAA Ship Rainier
July 10, 2006

Mission: Hydrographic Survey
Geographical Area: Kodiak, Alaska
Date: July 9, 2006

Tidal flats, Cook Inlet, Kodiak, AK

Tidal flats, Cook Inlet, Kodiak, AK

Pre-Cruise Log 

My NOAA Teacher at Sea adventure began with a long flight to Anchorage from Los Angeles International Airport. From Anchorage I caught a prop plane to Kodiak, which is an hour flight. Weather began to move in as we traveled to Kodiak, but I could see a few of the Aleutian Islands below.  The landing made me a bit anxious; since it appears that you are landing on the water.  The discomfort was worth enduring to observe the dramatic and beautiful scenery I saw as I landed. The plane flew over Cook Inlet which has enormous tidal flats.  The tidal range in the inlet is over 30 feet per day. ENS Jamie Wasser, NOAA Ship RAINIER’s Junior Officer, met me at the airport in Kodiak and escorted me to the ship.  Everyone thought I was so important since I was being met by an officer in uniform.

NOAA Ship RAINIER in Kodiak, AK

NOAA Ship RAINIER in Kodiak, AK

The RAINIER is docked at the U.S. Coast Guard Facility in Kodiak which is reported to be the largest in the United States. I take advantage of the great photo opportunity driving to the RAINIER dock.  Once aboard the RAINIER, I met Olivia Hauser, Junior Officer, and my roommate for the cruise. Olivia is very nice and extremely outgoing. Olivia gives me a tour of the ship, and I get settled inOlivia invites me to go eat Sushi and see “Pirates of the Caribbean 2” with some of the crew who are enjoying the last day of leave. The crew has just finished a leg and has a couple of days off before July 24, when we depart for the Shumagin Islands.  We leave at 5:00 in a van to go to the Sushi restaurant and eat, but there are 10 people and it takes a long time so we scrap plans to go to the 7:00 p.m. movie. I return to the room, check on my online class, and get ready for bed. The scenery in Kodiak is dramatic and full of geology.  One hillside composed of exposed volcanic rock is located near the dock.

View of a passage (hallway) aboard the RAINIER.  My stateroom is on the right

View of a passage (hallway) aboard the RAINIER. My stateroom is on the right

The sink in my stateroom.

The sink in my stateroom.

This is my stateroom.  My bunk is on the bottom.

This is my stateroom. My bunk is on the bottom.

Volcanic rocks on hillside in Kodiak, AK

Volcanic rocks on hillside in Kodiak, AK

Another view of the volcanic rocks in Kodiak

Another view of the volcanic rocks in Kodiak

Geoff Goodenow, May 4, 2004

NOAA Teacher at Sea
Geoff Goodenow
Onboard NOAA Ship Oscar Elton Sette

May 2 – 25, 2004

Mission: Swordfish Assessment Survey
Geographical Area:
Hawaiian Islands
Date:
May 4, 2004

Latitude: 19 19
Longitude 156 05
Sunny with scattered clouds
Air temp 26C
Barometer 1013.75
Wind 130 degrees at 9 knots
Relative humidity 59%
Sea temp 26.5
Ocean depth 2770 meters

Scientific and Technical Log

This morning we hauled in the longline. This is the first time this team has used the larger hooks and herring (as opposed to squid) for bait as a means of avoiding taking of turtles. In that sense, we had tremendous success — no turtles. But on the downside, we caught only two fish — a mahi mahi (Coryphaena hippurus),still alive, and a wahoo (Acanthocybium solandri) which had died on the line. Eyes, liver, blood, and muscle tissue were taken from both. For the experiments on vision that Kerstin is doing only live eyes are useful.

Some surface plankton tows were conducted over a couple hours this afternoon. Several eggs were gathered and preserved. More tows will be conducted after the longline is set.

When nothing else was going on, two lines were trolled off the stern.   This method yielded 4 fish including bigeye tuna (Thunnus obesus), skipjack tuna (Katsuwanus pelamis) and yellowfin tuna (T. albacares). These were sampled as above and in addition we kept stomachs for later study of contents. So 400 hooks sitting in the longline for 12 hours so far isn’t looking nearly as effective as a good old fishing line and a lure.

Tonight at 8PM we again set the longline, this one about 20 miles north of last night’s set. Because the winds are still very strong outside the shelter of the big island we are a bit restricted as to where we can go to fish right now. Winds are to becomes calmer over the next 48 hours.

Here is the longline set up in more detail than before. A spool holding about 40 miles of line sits parallel to length of ship on port side approx. mid-ship. Line feeds off to a pully along side of ship which directs line 90 degrees to stern. Via a couple more pullies the line goes to starboard side of stern. A team on the stern takes care of it from here. At center is person with basket of hooks attached to metal or monofilament leads with a clip on the other end. He withdraws the hook and clip, passing the hook to his right and the clip to his left while pulling the leader from the basket. The hook is baited, while the clip is passed to the next man to the left. On a signal about every 12 seconds, the leader is clipped to the line as it pours off the stern and the baited hook is tossed. A light stick goes on every fourth leader or so to attract fish. Better luck to us tonight!

Personal Log

My role this morning as line was retrieved was to record information (catch location, length, weight, sex) about each fish brought aboard and to assist in gathering muscle tissue samples for Brittany who is not present on this cruise as well as for others. Again I was brake man and bait boy on the longline tonight.

The afternoon hours seem to be those of least to do unless the troll lines are hot. Today I felt settled enough in the stomach to dare to enter a very confined space and enjoy my first shower at sea. Then I sought out a shady spot on the upper deck where I parked myself for a bit of reading. The wind was light and sea calm; I had a nice view of the west side of Hawaii. The lush, green slopes were interrupted in several places by lava flows. I had the opportunity to talk with the captain about many aspects of the ship, weather, ocean currents much of which I will try to incorporate into upcoming reports. But I was particularly interested in our rough weather of Sunday and he explained it as follows. As we crossed open water we were encountering winds of 20-25 knots, but as we entered the channel between Maui and Hawaii wind speeds were 35-40 knots. The reason for the increase is that both islands have very high mountains so the air is being funneled through a rather narrow slot and speeding up. This produced 10-12 foot waves with very short periods, and the ability to create a lot of discomfort in those at sea.

Tonight as we work, the light of a full (?) moon dances on the water.

Question:

One more (easy) location question for the astronomy buffs: Our latitude today is about 19 degrees north. What is the altitude of the North star (Polaris) as we view it from here? What is its altitude at your latitude?

OK, so we know where we are, but how did the Hawaiian islands get here? All of these islands are of volcanic origin. The Hotspot theory explains how the islands formed here. Briefly describe this theory.

Which of the islands (easternmost or westernmost) are the oldest in the Hawaiian Island chain? How long ago are the oldest islands estimated to have formed?

The Galapagos Islands also formed according to the hotspot theory. Which islands in that chain are oldest (eastern or western islands)? How old are the oldest of those islands?

For those who are wondering, yes, I do expect to be able to post some pictures, but we are not quite set up yet at this end to do so. That’s all for now,

Geoff