Sunday, March 27, 2016
Saturday, March 26, 2016
Thursday, March 24, 2016
Yesterday we spent most of the day collecting cores from the seabed. So, what is a core…well, if you can imagine sticking a tube into the ground and pulling it out with a plug of the bottom. Think about it this way…know when you have a drink at a restaurant, waitress gives you a straw…the you put the straw in your drink and put your finger over the top and pull some drink out of the glass in your straw. You have essentially created a suction in the straw allowing the drink to remain in the straw when you remove it from the glass. We are doing essentially the same thing, but on the sea floor. This allows us to collect "sediment" from the ocean.
To be clear, sediment is the dirt, the soil of the ocean. Particles that wash of the continent or are created in the water column sink through the depths of the ocean and accumulate on the sea floor. This has been happening for thousands, hundreds of thousands of years. So, these sediments hold a record of earth's history…information on ocean properties, changes in climate, alteration of the coast. All of these processes influence the physical and chemical character of the sediments being deposited on the sea floor. So, we collect these sediments to gain information on processes that are occurring in the overlying water column, the atmosphere, and the adjacent continents. These sediments act as a window into the geologic and recent past. The longer core we collect (longer straw), the further back in time we can see…
Given that background, we are interested in using these cores to gain a better understanding of how the continental margin, particularly the shelf-slope break, off NC, has changed and processes that lead to the accumulation or down-slope transport of sediments. We use geochemical tools (natural radionuclides, organic matter, among others) and physical character (grain size, porosity, bulk density, etc.) of the sediments to interpret the source, mechanisms of delivery, age, and how the sediments have been altered with time. The data collected form the sediments, together with the information gained from the multibeam, EK80, and Knudsen (se earlier blog post) will provide the initial data for several working hypotheses we hope to test in greater detail in the near future.
As you walk down the stairs to the main deck, you're faced with a near-life-sized photograph of Neil Armstrong, the ship's namesake. It's a striking photo. Despite the space suit and lunar background, he looks so human, so normal.
Neil Armstrong was an amazing individual: a naval aviator, experimental test pilot, aerospace engineer, university professor, and, of course, world-renown astronaut. It's reported that he flew over 200 different models of aircraft, including the X-15 hypersonic rocket plane (https://www.nasa.gov/centers/glenn/about/bios/neilabio.html). His first step on the moon was a monumental occasion, and indeed, it symbolized much more than a space walk.
Neil Armstrong led the Gemini 8 mission which launched on March 16, 1966 - exactly 50 years prior to the start of our oceanographic research cruise. It's an honor to have one of the first research cruises aboard the R/V Neil Armstrong. I must admit when I boarded the ship, I questioned why it was named after him. I didn't doubt his accomplishments or abilities, but I wondered why not honor a marine scientist. But now I realize there couldn't be a more fitting name for a research vessel - to celebrate one of the United States' greatest explorers. Armstrong has inspired generations of young scientists. To this day, his moonwalk still seems unfathomable. Let's hope a new wave of ocean scientists will use this ship to better understand our water planet.
It is always exciting to go to sea, but this voyage is particularly energizing as we are approaching it with a spirit of exploration. Unfortunately, this is not always possible as most research today (even oceanography) is conducted in a very calculated and controlled fashion, requiring proposals, hypotheses, clear plans and detailed budgets. Certainly, this is important as effective research must follow the scientific method and funding must be invested wisely. But, because this expedition is for scientific verification of the new ship, it is allowing us to have a more flexible and free approach. This is wonderfully refreshing, and the vibe on the vessel seems different as a result (i.e., less stressed and more excited). I'm hopeful that many other scientists that come aboard this vessel will be inspired by Armstrong. Like space, the oceans are vast and largely unexplored. We need more scientific adventurers to help us explore and understand the depths of the sea.
By: David Sybert
The Kasten Core has been unleashed! In an effort to get a more complete and deeper core scientists aboard the R/V Armstrong have turned to the Kasten Core. The Kasten Core is a large square stainless steel tube that is pushed into the sediment by a series of weights that are positioned above the steel tube. The core is dropped down to the seafloor, the weights push the tube into the sediment, and as the core is brought out of the sediment two small doors close inside the tube, which keeps the sediment in the tube as it is brought back to the surface. When it arrives back on deck a side of the tube is removed allowing access to the core inside. Samples are then collected for the numerous studies using the sediment.
Yesterday there was much success in coring with enough mud for everyone! Samples were taken from over 400 meters underwater. As the evening drew late there was also sampling of potential methane seeps on the sea floor using a CTD and deep-water camera. Stay tuned for some imagery of what the sea floor looks like around one of the potential seeps.