Bad weather—bad for some, good for others

August 4, 2013

Bad weather has unfortunately meant that we are unable to investigate gas hydrate sites in the vicinity of Eel Canyon. Instead we are steaming south to use the remotely operated vehicle (ROV) to explore and collect cores in Mendocino Canyon. Whilst this is bad news for most people, it’s good news for me, as we will be collecting cores that will complement a larger dataset of cores that I have been working on during my postdoctoral fellowship at MBARI.

The existing core dataset comprises a suite of over 100 precisely located vibracores collected in numerous canyons along the northern California margin. The purpose of analyzing this dataset is to better understand the types of sedimentary deposits that exist within submarine canyons, their distribution, and the processes responsible for their formation. This is important because submarine canyons are the conduits by which sediment, pollutants, and nutrients are transported from the continental shelf out into the deep ocean. Despite their importance, submarine canyons are remarkably poorly understood because it has proven difficult to accurately sample these heterogeneous and bathymetrically complex environments using traditional ship-based coring techniques. The MBARI vibracoring system operated by a remotely operated vehicle (ROV) provides the unusual opportunity to locate cores precisely within the canyon system.

So far, the core dataset has not only revealed the great variety in the types of deposits that occur in the canyons: from coarse-grained deposits containing boulders and gravel to fine grained deposits comprising silt and mud, but also that distinctive processes operate locally within the canyons. For example, pairs of cores collected within 30 meters elevation of one another reveal that coarse-grained chaotic deposits are restricted to the basal canyon floor, while finer-grained deposits occur at higher elevations on the canyon walls. This enables us to better understand the nature of the flows that laid down these deposits by constraining the thicknesses of different components of these flows. This is important because the flows that transport sediment through submarine canyons remain one of the most poorly understood and least well monitored major sediment transport processes on our planet.

Esther Sumner works with sample cores.

Esther splits, photographs, and describes the sediment collected with push cores.

— Esther Sumner

Steward Patrick Mitts enjoys fishing and often shares his catches with the lucky crew and scientists on the Western Flyer. He will serve these salmon over the next couple of days and freeze some for later legs of the cruise. He also has a smoker on board to make smoked salmon. As a vegetarian, I can’t tell you firsthand how good they are, but from what I’ve heard, it’s the best salmon you can get. Patrick takes care of all of our various dietary needs and adapts to each new team of scientists that comes aboard. We can’t thank him enough for keeping us fed and happy!

Erik Larson and Patrick Mitts catch salmon

It’s salmon season! In the evenings, some of the crew take advantage of our northern location close to shore to fish for salmon. Erik Larson and Patrick Mitts proudly hold up their catches.

— Susan von Thun