As many of you probably heard, there was an 8.2-magnitude earthquake off the coast of Northern Chile on Tuesday night. As with any earthquake around a coastal region or on the ocean floor, there is great concern about the formation of a tsunami. A Tsunami is series of waves with a very large wavelength. Think of a series of waves hitting a beach. The distance between each wave hitting the shore is the wavelength. Now picture a wavelength that is 100s of miles long! Because the wavelengths are so long, the waves travel at very high speeds, around 600 miles per hour, in the deep ocean. This is the speed at which a commercial jet plane travels! However, the wave height (the height from the base of the wave at the water line to the top of the wave) is very small, maybe a few feet tall. As you can imagine, a boat or ship in the open ocean wouldn’t even notice such a tiny wave.
Below is a screen shot from a CNN video report about the earthquake. In this video you can see how the waves propagate out from the source of the earthquake out into the ocean (red arrow).
The story changes, however, when the depth of the ocean decreases, such as when approaching land. All of that energy in that fast wave gets slowed down and subsequently the height of the wave gets bigger, and sea level near shore can rise at least 50 feet! Thankfully, our colleagues are out of harms way from tsunamis because they are in the middle of the deep, open ocean.
The ship and its inhabitants ARE, however, subject to waves that are created by storms and strong winds. Joaquin made a video of the wave action that you can see below. Here are some freeze frame ‘action shots’ from the video.
And, lastly, I thought it would be good to show some pictures of how cold it is that far south and how challenging it can be to work outside on deck in the cold. In this picture you can see icicles hanging off the ship during recovery of an IOP package deployment.
Water intrusion during recovery of the IOP package
Mike and Scott are having a conversation as they wait for the IOP package to return to the surface of the ocean. I wonder what they are talking about???
A very intense conversation ensues while waiting for the IOP package to return to the ocean surface
You can watch an entire IOP deployment below.
Lastly, when working so close to the continent of Antarctica, there must be a sighting of an iceberg.
At approximately 60° South and 174° East the FSG members sampled their first official station of the field campaign. The solid red line in the map below denotes the current ship track (as of March 27th). The ship has not yet reached the P16S line that begins at 150° West (the blue circles on the map below).
The FSG will deploy an IOP package at one station each day. The FSG IOP package is an assemblage of instruments that collect data for temperature, salinity, depth, absorption of particles and dissolved components, and particle scattering. The instruments are contained within a metal ‘cage’ that is lowered on a wire to a chosen depth in the water column. The data collected by the instruments are saved to a type of hard drive located within the cage. Before the cage can be deployed, weight must be added so that it can sink.
Adding weight to the IOP cage
Here, the cage with all of the instruments is being lifted off the deck of the ship and lowered into the water.
Deploying the IOP package off the side of the ship
And, sometimes, King Neptune decides to send a wave your way. But that is why we wear our safety gear!
Scott catching a wave-It’s all part of the job
The FSG also collects surface water samples in conjunction with the IOP package deployment. A weighted tube is lowered over the side of the ship, and a large peristaltic pump gently transfers seawater to a large container (carboy).
Lowering tubing over the side of the ship to collect surface water
Joaquin filling a carboy with surface water pumped off the side of the ship
The water is filtered and processed back in the laboratory on the ship.
Now, let’s take a moment to understand the significance and importance of hydrographic field campaigns. Oceanic and atmospheric processes are tightly coupled. Temperature and freshwater fluxes between the ocean and atmosphere are in control of climate variability. A good example of this strong ocean-atmosphere relationship is El Nino Southern Oscillation or ENSO. During an El Nino event, the temperature structure of the equatorial Pacific Ocean is disrupted. The central equatorial Pacific Ocean becomes warmer than normal affecting tropical rainfall in Indonesia and global weather patterns. The objective of the Climate Variability and Predictability of the ocean-atmosphere system, or CLIVAR, program is to understand this dynamic coupling and model future ocean-atmosphere variability by collecting and analyzing ship-based global observations. The International CLIVAR program is a continuation of its predecessors: the Tropical-Ocean Global Atmosphere (TOGA) and the World Ocean Circulation Experiment (WOCE). The TOGA program was formed in 1985 to study the relationship between the tropical ocean and the global atmosphere with the ultimate goal of predicting variability on various time scales. The WOCE program began in 1990 with the objective to study global ocean circulation and its relationship to the global climate system over long time scales using global observations. The US-CLIVAR program contributes to the international program as well as the World Climate Research Program. You can learn more about the US-CLIVAR program here.
The guys are finally on their way! The R/V Nathaniel B. Palmer set sail from Hobart, Tasmania on March 20, 2014 ( GMT +11 hours). The science party is made up of a total 29 scientists, 9 of which are graduate students. The first Go-SHIP station is located at 67°S, 150°W. While in transit, scientists will deploy the first Bio-Argo float of the campaign, 6 days from sail. An Argo float is a battery-operated, autonomous float that can move up and down the water column collecting temperature and salinity profiles up to a 2000m depth by pumping fluid into and out of a bladder to manipulate buoyancy. A Bio-Argo can collect measurements of chlorophyll-a and backscattering, in addition to salinity and temperature profiles. The deployment of Bio-Argo floats is particularly important for validating ocean color remote sensing data. For more information about Argo floats, you can proceed to the following links:
Setting up a scientific laboratory on a ship is no easy task. Space is usually limited and you must be able to play well with others. We have filtration equipment (the large wooden frames) set up to collect the biogeochemical parameters, i.e. phytoplankton pigments, particulate organic carbon and particle absorption. The parameters are collected onto small paper filters and frozen for future analyses back at NASA Goddard. We also have two instruments set up on board to measure colored dissolved organic matter (CDOM), which is like tea, compounds extracted from plant material that can flow out into the ocean via rivers. While in transit to the first station Mike, Joaquin and Scott are busy collecting samples.
Mike Novak filtering samples
Particles on a filter pad
Joaquin Chaves preparing samples for storage
A major addition to this year’s field campaign is a ‘souped-up’ underway-sampling system built by none other than Scott Freeman, our optics expert on board the Palmer. The set-up contains multiple instruments that collect dissolved and particulate absorption, CDOM fluorometry, chlorophyll and particle scattering at 660nm. The system is connected to the ship’s seawater system that pumps clean seawater from <10m depth through the ship and then to faucets at which the water can be accessed. The term ‘clean’ means the plumbing that facilitates seawater pumping to the laboratories is routinely checked for clogs and algae growth.
Scott Freeman and the underway sampling system
Lastly, a blog post isn’t complete without a gratuitous photo of macrofauna. Here is a photo of a petrel taken by Joaquin Chaves. Can anyone identify what kind of petrel this is?
Week 3 provided 7 days of much needed sunshine allowing for a study-site-wide dry down of soils and a significant increase in crop growth. Field crews were able to collect vegetation samples twice and soil moisture measurements four times!
We’ve been rained out for four straight days Friday through Monday due to unstable weather conditions in the area – not exactly what we expected! On the other hand we should certainly observe some pretty wet fields when we make our next PALS flights.
On Saturday things looked good in the early morning despite some low-lying fog and expectations that a weather front to the East might move into the area by early afternoon. So we gave the “Go” signal for the sampling teams to head for the fields. Meanwhile at the airport the fog thickened, so take-off was put on hold. Seth and Ian took advantage of the delay to work on some instrument troubleshooting.
By the time the fog at the airport lifted Rich determined that the weather front was moving in much faster than expected and would probably reach the edge of our sampling domain by mid-morning. So we reluctantly aborted the Twin Otter flight for the day and notified the field crew (who were no doubt also anxious not to get caught in the storm). When the storm hit it was a big one! The tornado chasers were out in force, we heard, but none were sighted according to the news (tornados, that is).