Dispatches from the Field: Massachusetts, Maine, and the Merrimack

Hello from Gloucester Point, Virginia!

I am already missing the cooler weather of New England, having just returned to muggy Virginia from two very intense, very rewarding weeks of field work with my project advisors Dr. Christopher J. Hein and Claudia Shuman, a PhD student at the Virginia Institute of Marine Science.

While we worked on many field projects, the overarching goal of all the projects (including my summer research) is to better understand how sediment feeds barrier islands and the system of marshes, tidal  channels, and mud flats behind barrier islands, called the back-barrier system. We can consider coastal sediment supply in the long-term (thousands of years), short-term (decades to years), and/or somewhere in between (hundreds of years). We can also consider various types depositional locations, from barrier islands, to marshes, to tidal flats. Our two week field work adventure involved all three timescales and all three locations.

June 7 — The Long Haul. 

Fourteen hours of driving from Gloucester, Virginia, to Rowley, Massachusetts. On the way up we towed an insane amount of equipment (~10,000 pounds, including the still-to-be-named Geoprobe drill rig (a powerful tool for taking cores to look at thousands of years of coastal sediment deposition). The trailer pictured here houses the Geoprobe (….George? Geo? Jim? Richard?….suggestions on a good name?) and our ground penetrating radar (GPR) system that allows us to look at sedimentary structures present underground. (GPR can also be used to attempt to find union leader Jimmy Hoffa, as seen on Mythbusters. Seriously, the video does a decent job of showcasing how GPR works).

Tools of Coastal Geology:

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Top: Coastal Geology Trailer; Bottom: Geoprobe drill rig and miscellaneous equipment  

Our team had the pleasure of staying at Rowley House, a part of the Long-term Ecological Research Station at Plum Island and a facility of the Marine Biological Laboratory. It was a real treat with spectacular views of the Rowley River and Great Marsh!

Rowley House at dusk:

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June 8-9 — Going deep. 

We worked with the local Geoprobe salesman Vic Rotonda who introduced us to a dual-tube system that allowed us to core deeper than ever before with the Geoprobe system on Plum Island, a barrier island in Massachusetts. We got 75 feet down, all the way to the glaciomarine deposits underlying the barrier island layers. The glaciomarine clay is more famously known as “Boston Blue Clay” and formed from a combination of glacial and marine processes.

The VIMS Team:

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The next day, Claudia, Chris, and I took an additional core at the same location also using the new dual-tube system. Once again we hit Boston Blue Clay. Going this deep will allow Claudia to use “biomarkers” to understand the origin of the sediment that built the barrier islands. This work looks at timescales of thousands of years.

June 10-11 — Coring Joppa Flats. 

With the help of UMass graduate student Zach Strommer and VIMS graduate student Andy Fallon, Claudia, Chris, and I learned to use a canoe-mounted piston-core system. The system allowed us to core ~2 meters (about 6 feet) deep into Joppa Flats, an estuarine sand and mud flat at the mouth of the Merrimack River in Massachusetts. We cored a transect of 5 cores with duplicates at each site. Using these cores we can look at changes in the deposition (in terms of amount, mineral components, texture, size) at multiple time scales, including at least the last few hundred years dating back to early Colonial occupation and potentially earlier. In the time from about 1600 to the present we want to better understand how human actions (deforestation, damming, dredging) impact sediment supply to the coastline, particularly to barrier islands and their back-barrier systems.

Piston Coring on Joppa Flats:

IMG_2110 IMG_2126 IMG_2146_2 IMG_2128_2 The piston core system involves a canoe-based pontoon system, with a platform for coring. 

 

June 12 — To Rockport, Massachusetts.

In Rockport, Andy and I helped Zach with exploratory work for his masters thesis. In addition to contending with a brood of potentially angry swans, we cored a coastal pond in Rockport looking for evidence of washover deposits from coastal storms. Overwash, the process that produces washover deposits, results when high energy waves entrain beach sediment and send it over the beach crest, where it remains deposited after the storm has died down. Coastal ponds, or barrier ponds, are ideal locations to capture preserved records of overwash events. These deposits allow geologists like Zach to reconstruct past tropical storms and hurricanes, providing better understanding of how climate influences these systems.

June 13 — The Maine Idea. 

We spent Friday night and most of Saturday enjoying the coastal areas of Maine at Popham Beach and the areas around Bath. While lobsters rolls were consumed, we did get some work in, running ground penetrating radar lines in search of the 5000 year old abandoned (and now filled in) channel of the Kennebec River. Again, different timescales and different tools—a good example of the diversity of work taking place in coastal geology.

June 14 — Boston and Cambridge, MA via Rowley, MA. 

A day of rest in a busy schedule of field work. Thanks to the convenience of commuter rail proximate to Rowley House, Claudia and I were able to spend a few hours in Boston, exploring Cambridge and dining on delicious Irish food. The beauty of a field site so close to major cities and the comforts of home? Priceless.

June 15-19 — To the backbarrier! 

For the second week of field work, the Virginia Institute of Marine Science team joined colleagues from Boston University and the University of New Orleans. Early in the week, we took vibracores in diked freshwater marshes/ponds behind Plum Island to better understand the stratigraphy of these manmade systems.

Additionally, Chris used a hand auger to collect samples from the salt marsh where a study is underway to determine how quickly the marsh is accreting, or building up vertically.

Towards the end of the week, we ventured out in boats to retrieve instruments that spent the most recent month of their electronic lives collecting important data on waves, tides, and salinity in and around the Plum Island Sound.

Not only do I have the cores for the summer research I am doing, but the trip provided hands-on lessons in essential field methods of coastal geology.