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Congrats for spring 2022

Tyler Souza successfully passed his MS comprehensive/qualifying exam this term, and David Go received the 1st place award for undergraduate poster at the 1st annual EMES student research symposium ~ Congrats Tyler & David!

 

Congrats John ~ MS degree 2021

John aboard the R/V Sikuliaq in 2019 (Beaufort Sea) – photo courtesy of John Guillote, OnPoint Outreach.

Congratulations to John Malito for completing his MS degree in November, following the successful defense and submission of his thesis entitled “Evolution of Arctic continental shelves: modelling morphodynamic feedbacks to climate-driven increases in sea states.” John joined the lab in fall 2019 and participated in a R/V Sikuliaq expedition to the Arctic Ocean, presented undergraduate research at AGU, presented Alaska research in several virtual conferences during covid, assisted with local field efforts, and led a collaboration with Dr. Jaap Nienhuis at University of Utrecht during his time at UNC. His research addresses the millennial-timescale morphodynamic evolution of Arctic continental shelves (sections of the Alaskan Beaufort Shelf, specifically) given a change in wave climate that represents the ongoing evolution of Arctic sea states in response to multi-decadal reductions in sea ice. This work is important to helping the Arctic science community understand how coastal erosion leads to feedbacks on the continental shelf, in the form of re-deposition of sediment which attenuate waves and serves to regulate how much wave energy reaches the coast in a warming Arctic.


Fall classes & new Harrison Bay samples – update from Josie

It’s been a whirlwind start in the Eidam Lab! Starting in Summer 2021 I had the honor of joining the 2021 R/V Ukpik expedition to Harrison Bay, AK where we collected seabed samples, cores, CTD and LISST transects, vessel-mounted profiling data, and geotech data for ~2 weeks. This semester I have been taking classes and processing samples from the field. The figure here shows a spatial distribution of our grab samples with the mud fraction denoted by the color bar. “Highly variable” has become my new motto! I’ll be continuing to process samples and analyze results as we plan our second field collection aboard the R/V Ukpik, Summer 2022.


Greenland coastal erosion work – Gregor Lützenburg, visiting PhD student

After a successful field season in Greenland during summer, Gregor joined us at UNC as a visiting scholar in fall. In his PhD, Gregor is investigating the processes of bluff erosion in Denmark and Greenland. From the data collected in the field, Gregor calculated erosion rates of a coastal bluff on Disko Island in western Greenland. The investigated bluff consists of a heterogeneous matrix of hard rock pillars with pockets of coarse clastic sediments in between and parallel fossil beach ridges on top. The coarse sediments are eroding during precipitation events, forming erosion channels at the bluff face and accumulating the sediment at the bluff base. Waves are removing the sediment in front of the bluff during storms with elevated water levels.

Drone image of a section of the 25 m high bluff in the upper panel and erosion rate calculation in the lower panel. Green points indicate no change, orange points indicate medium change and red points indicate high rates of change in a time span of two years.

 


Field trips return!

After an odd year of virtual classes and hyper-local field trips during covid, we returned to the coast this year for our MASC 503 (Marine Geology & Geophysics) field trip to explore coastal barrier-island and lagoon dynamics with Dr. Tony Rodriguez and PhD candidate Molly Bost from IMS. We enjoyed beautiful weather and collected some example marsh cores, sampled the mud in Cape Lookout Bight, and looked at eroded dunes on the barriers.

 

 


Gearing up for Alaska Beaufort Shelf sampling (spring & summer 2021)

This spring and summer we’ve been obtaining permits, UNC travel permissions, and NSF travel permissions, designing mini moorings, and assembling, packing, and shipping all of our field gear for this summer’s Alaska shelf survey. Half of the gear was shipped in April and most of the remainder was shipped in June. Our science party is Emily, Josie, Nick Brilli (VT), and Dan Duncan (UTIG). We’ll be surveying from the R/V Ukpik, a well-outfitted local contract vessel which is commonly used for scientific and industry work. We’ll fly in to Prudhoe Bay, an industrial base serving the nearby oilfields. From there we’ll transfer our gear to the boat at West Dock, on property managed by Hilcorp, an oilfield services company as part of an arrangement with the State of Alaska. The North Slope of Alaska is a gently sloping, low-relief region north of the Brooks Range which encompasses the National Petroleum Reserve and Arctic National Wildlife Refuge. The Trans-Alaska Pipeline System, one of the largest pipeline systems in the world, begins at Prudhoe Bay and runs more than 800 miles south to Valdez, a port near the Gulf of Alaska (northern Pacific). The North Slope lies within a region of continuous permafrost, meaning that below an “active layer” at the surface which freezes and thaws seasonally, the ground remains frozen. This perennially frozen ground accumulates diverse unique geomorphic features, include ice-wedge polygons and thermokarst (“thaw”) lakes. The thaw lakes make the North Slope tundra look like swiss cheese in satellite view. The lakes tend to be elongated. Surprisingly the long axis tends to be oriented perpendicular to the prevailing wind patterns, due to circulation and thawing effects driven by wind patterns.

Because of the ice-rich nature of Arctic coastal plain soils, Arctic coasts are susceptible to rapid retreat when ice-rich ground is thawed during the summertime. Wave action helps remove the sediment that is eroded from bluffs, but the fate of this material is poorly constrained. Does it remain near shore, or is it efficiently transported offshore by waves and currents? Is transport on the continental shelf dominantly along-shelf or across-shelf toward the shelf break? How mobile are sediments on the shelf? We are gathering observations of the ocean physics and resultant sediment transport in order to address these questions.

April packing efforts in the lab – we assembled moorings and sediment sampling equipment, and shipped it by truck to Prudhoe Bay for storage.
Prudhoe Bay region, including West Dock where we’ll depart for the Jul/Aug survey.
Schematic of sediment erosion from the bluffs and delivery to coastal environments. Our research questions begin at the water line: what happens to sediment after it is released from bluffs (and delivered by rivers)?

 


IceSat2 trial survey (6/2021)

Emily, Zach, and Tyler ran a trial survey at Jordan Lake on June 14, coincident with an early evening IceSat2 track located close to the Farrington Point Boat Ramp (about 20 min from campus). The goal of our initial survey was to test equipment and get an example dataset that we can use as a basis for developing processing routines. We will be working with the ATLAS03 product (photon returns) and working to integrate both the photon signal and the suspended-sediment signal within the water column, in an effort to calibrate the ATLAS product for sediment inventories in shallow waters. We’re looking forward to building our database of in situ measurements this fall, including surveys in coastal waters.

First trackline across Jordan Lake
Jordan Lake test survey on an evening with mixed clouds
IceSat2 ground tracks over North Carolina during cycle 11 (early summer 2021) – tracks downloaded from NASA

New River (6/2021)

We teamed up with the Flood Hazards lab for a day trip to New River (a coastal watershed near Jacksonville) to collect bathymetry data by kayak. We successfully sampled at three sites and saw only one snake!

Sarah Brannum (left, UNC Geology ’21) and PhD student Lauren Grimley (right) collecting ADCP data. Lauren is working with Dr. Toni Sebastian to use these data as validation for a hydrologic model of New River.
New River on the North Carolina coast

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


Summer 2021 – general updates

This is shaping up to be a busy summer as we welcome new members to the lab and catch up on 2020 + 2021 field sampling. Here are updates on all the exciting projects we have in progress:

 

John – Alaskan Beaufort Shelf sediment transport & morphology modeling

This spring John has been working to incorporate new shelf data from fall 2020 data as guidance for the model setup, and has been extending the shelf modeling to a second transect near the Flaxman Islands. Through summer, he’ll be running several experiments in the model to assess the 1000-year shelf evolution under modern and projected wave climates, as well as short-term sedimentary response to storms. See a full update on the Alaskan Beaufort Shelf project page.

Beaufort Shelf transects used in the sediment-transport model: Harrison Bay (B) and Flaxman Islands (C).

 

Tyler – Coos Bay sediment dynamics

In partnership with UO and the South Slough National Estuarine Research Reserve, Tyler just completed a successful coring trip to Coos Bay. A full update (with photos!) is available on the Coos Bay project page.

Coos Bay eelgrass beds

 

Owen – OBS construction

This summer I will help with the open OBS sensor project and assist with Coos bay grain size analysis. I have a summer goal of reading a paper a week and will be attempting to build a PC.

 

Gregor – coastal evolution in Denmark and Greenland

We are looking forward to Gregor Luetzenburg, a PhD student from the University of Copenhagen, joining the group this fall as a visiting scholar. This summer Gregor will work to collect data on the sedimentary cliffs at the southern coast of Disko Island in western Greenland. In his PhD project, Gregor is looking at the drivers of coastal cliff erosion in Denmark and Greenland. Together we are investigating the coastal sediment transfer and the mechanisms of cross-shelf transfer in Greenland. Not much is known about the role in sediment supply from those soft sediment cliffs. Rising sea levels and increasing temperatures might accelerate the erosion rates in the coming decades.

Soft sediment bluffs in Greenland. (Photo credit: Kristian Svennevig)

 

 

We are also excited to welcome Daniela Zarate to the lab! Daniela is teaming up with Tyler to analyze grain-sizes, organic contents, and radiochemical signals in the Coos Bay sediment cores.

 

 


Spring 2021

Spring semester was busy – many of us were involved in MASC 490, a special topics course on Fluvial and Coastal Sediment Dynamics. The course was taught in person starting in February, and included some local stream sampling, Matlab-based problem sets, an introduction to fundamental sediment transport equations used in engineering and sedimentology research, and extensive paper discussions about the dynamics of coastal systems. John passed his qualifying exam (congrats John!), Tyler began analyzing short cores from Coos Bay, and McKenzie and Owen made great progress designing sensor housings and constructing PC boards for the OBS project.

An example hysteresis plot of suspended-sediment concentration versus river discharge – made using Matlab for our sediment dynamics course. This example uses USGS data from the lower Mississippi River in 2014.

 


Fall 2020

Fall semester was busy with classes, reading, and field work. Here are some photos from the field:

Neuse River sampling, 14 Nov

We took advantage of some recent rains to collect ADCP transects on the Neuse at New Bern and Kinston. We found mud at the New Bern end where the estuary widens, and sand in the narrower upriver reaches at both New Bern and Kinston. Josh Himmelstein (grad student, IMS) got some great images of the survey – and a video here: Neuse River sampling 14 Nov 2020

An aerial view of the Neuse, with flooded forest areas visible at left (credit: Josh Himmelstein)

 

An aerial view of our survey boat (credit: Josh Himmelstein).

R/V Sikuliaq survey, Sep/Oct 2020

Emily joined the UW-APL CODA team (CODA project page) for a mooring recovery trip in the Chukchi and Beaufort seas, which provided an opportunity to collect data in support of the Alaskan Beaufort Shelf sediment transport study. The trip was a great success, and we learned more about the diversity of sediment textures at three study sites.

 

 


Summer 2020

This summer we maintained momentum with papers, modeling, and reduced lab and field work. So far it has been a good year, all things considered! Here are specific projects we’ve been working on ~

 

From John:

My masters research at UNC has been spent building a cross-shelf model to evaluate long term morphological changes in the warming Arctic. This summer was dedicated to tuning and tweaking the hydrodynamic and sediment characteristics of Arctic shelves to serve as a foundation on which future changes in climate and sediment transport will be investigated. (Figure below) I have taken transects of 90 m bathymetry from the Beaufort shelf and averaged them into one representative cross shore profile to serve as the starting point in my model. Wind and wave data have been taken from time series spanning several decades to provide an approximate “present day” hydrodynamic regime in the model. The result is a representative Arctic shelf that is sensitive to slight changes in wind and wave energy over 2000 years and stabilizes into a steady state of change after several hundred years.

This fall I will continue tuning and adding elements to make the model reflect the unique characteristics of Arctic shelves. I am excited to continue this research and investigate how Arctic sediment transport dynamics will change in the next century!

 

From Tyler:

It was a great first summer in the Eidam Lab! I spent most of the summer working on a project examining sediment transport dynamics in the Peace-Athabasca Delta in northern Alberta, Canada. I started by processing data collected from an acoustic Doppler current profiler (ADCP) a device that uses sonic beams to measure suspended sediment flux using backscattered sound and the doppler shift.  I then focused on sizing hundreds of sediment grab samples collected from the river bottom throughout the delta.  To size the sediments, we used a laser particle sizer that measured refraction of lasers around suspended sediment to detect the size of the particle.  I was also able to get in some fieldwork on our local North Carolina rivers as we field tested sampling methods first in our local reservoir Jordan Lake and later on the Tar River under two different flow regimes.  It has been great to jump feet first into research in the lab and I am looking forward to the fall where I will be beginning to build the basis of my master’s project looking at sediment circulation in a West Coast Estuary.

 


Feb 2020 – Ocean Sciences Meeting

Emily presented the current results of the Coos Bay sediment modeling work at the biennial Ocean Sciences meeting, and connected with polar and coastal colleagues including John and Becca Guillote of the @iceinmotion team – thanks for the great conference photo! The Beaufort Shelf team also had a productive meeting to strategize and coordinate upcoming Arctic field work. Post-conference activities included visiting some of the varied coastal terranes near San Diego – an interesting mix of sandstones and volcanics.

 

 


Dec 2019 – AGU Meeting

Emily and John participated in the annual AGU meeting in San Francisco. John gave an excellent poster on his research in anthropogenically modified Brazos River sediment routing, from his undergraduate research with Dr. Dave Mohrig’s lab at UT Austin. Emily presented on morainal bank evolution in LeConte Bay, and Mekong subaqueous delta dynamics.

C32A-08 – Morainal bank evolution and fjord infilling during a tidewater glacier stillstand, on seasonal to decadal timescales

EP31A-01 – Subaqueous deltas under stress: interplay of bed stress, sediment transport, and transport direction for the Mekong system compared to other global deltas (Invited)

EP23E-2255 – Competition of Nearby River Deltas: How the Brazos River Delta closed the San Bernard River Mouth with the help of Coastal Infrastructure

John presenting his undergraduate thesis work at AGU 2019

 

 

 

 

 

 

 

 

 

 

 


Nov 2019 – R/V Sikuliaq cruise

Emily and John traveled to Nome to join Dr. Jim Thomson’s team from the UW Applied Physics Lab on a survey of wave-sea ice interactions in the Chukchi Sea and Beaufort Shelf – part of their ongoing Coastal Ocean Dynamics in the Arctic project. We were tremendously grateful for the opportunity to collaborate during the survey, as part of our ongoing NSF study of sediment dynamics on the Beaufort Shelf. Being able to use the Sikuliaq platform during the fall freeze-up season allowed us to access and measure seabed sediment textures toward the end of the higher-energy open-water summer season, and measure particle fluxes in the water column during some wave events. The cruise was documented in fine style by John and Becca Guillote of the @iceinmotion team through their blog. We are grateful to for the wonderful photos they shared highlighting some of the sediment sampling!

John shares his experience from his first major research cruise (and first time working in the Arctic) here:

In November of 2019, the research vessel Sikuliaq made a transit northward through the Bering Strait at the start of a month-long journey to the Arctic. It was on the first leg of this transit that I was introduced to the wonderous, adventurous, and dangerous world of polar oceanography. The Sikuliaq is an ice-breaker featuring a spoon shaped hull that is designed to push itself over sea-ice and crush it from the top. With that being said, the stormy Bering sea is not the Sikuliaq’s natural habitat. Conditions were turbulent during this first leg of the trip, but I would later find this to be an outstanding experience in science and beyond.

The primary mission of the research cruise was to support the Coastal Ocean Dynamics in the Arctic (CODA) project, a study led by chief scientist Dr. Jim Thomson of the University of Washington aimed at observing the changing Arctic, particularly the Chukchi and Beaufort seas on the northern coast of Alaska. Given the decreasing presence of sea ice in the Arctic, it is expected that the increased extent and duration of ice-free open water could lead to dramatic changes in the energetic regime of the coasts. With less sea ice to suppress wave action driven by storms, one might expect these larger waves to accelerate coastal erosion, alter the physics of ice freeze-up in the fall, or lead to unpredictable changes in the morphology of the continental shelf. Though these topics have been studied previously, in-situ observations of the Arctic are few and far between given the remote location and hazardous conditions of the study area. Therefore the 2019 CODA cruise was a tremendous opportunity to collect brand new data to provide insight into the rapidly changing Arctic.

Dr. Emily Eidam and I were graciously invited onto the cruise by Jim Thomson to act as “scientific stowaways”, to assist in the CODA operations when applicable but also to collect data for use in our own Arctic research project. Dr. Eidam and I have begun investigating the fate of Arctic coastal sediments in continental shelf environments, an NSF-funded project to observe and model sediment transport and seabed properties on the Alaskan Beaufort Shelf. In the rapidly warming Arctic an increase in sediment supply (via coastal erosion and riverine input) and increasing wave energy may change the characteristics of Arctic coastal environments. The CODA cruise was an opportunity for us to gather preliminary datasets of the seabed and energetic characteristics of our study area. We joined a diverse group of coastal oceanographers, wave physicists, field technicians, crew members, and a team of fisheries biologists to gather brand new data to help observe the changing Arctic firsthand.

To achieve this, we spent weeks at sea stopping at pre-defined transects in the coastal Chukchi and Beaufort seas to deploy and recover equipment that measure the physical properties of the water column, waves, and seabed. More than once we found ourselves chasing stormy weather, where we sought to conduct multi-day sampling operations to document the conditions before, during, and after wind events that alter the properties of the water column and affect the timing of the fall freeze-up of sea ice. Of course this means that we spent hours on deck in somewhat rough seas (our proximity to the shore and sea ice considerably dampens wave action), gusty winds, snow, and cold temperatures. We measured wave and current driven sediment suspension on the seabed and found a diverse spatial distribution of sediment sizes on the seafloor. At every hour of the day a new observation was made, or a new time-series plot left us all huddled around a laptop screen enthusiastically discussing a squiggly line on a graph.  In all, over 360 individual CTD (Conductivity-Temperature-Depth) readings and 195 samples of seabed sediment were collected to document sediment transport processes – representing only a fraction of the total data obtained by all teams on the trip, and a key step toward learning about the changing Arctic.

Life on the ship with a diverse assortment of scientists for a month is exactly as fascinating as one would expect. It is impossible to be an introvert on the ship, with small spaces being constantly busy. But this provided a great opportunity to meet new people, share stories, talk science, and shoot the breeze with any of the wonderful scientists and crew members on board. We learned about particle physics, seabirds, whale migration, sediment dynamics, fish nets, and many other topics in our daily science meetings that featured a short seminar-style lecture from one of the scientists about their research. We spent hours each day waiting to arrive at the next sampling site, changing batteries, thawing the ice off of our gear, sorting through mountains of sediment sample bags, writing up code to process our data, and so much more, but there was never a moment of monotony. As a true rookie aboard the ship (a first year masters-student), I spent the bulk of the month functioning like a sponge, absorbing every piece of information and experience that crossed my path. I am incredibly grateful for Jim Thomson and Emily Eidam’s invitation to begin my young academic career with an adventure that provided countless experiences that will be difficult to ever replicate. These include playing ultra competitive games of UNO, spending a week yearning to see the sun peek re-emerge from the darkness of the Arctic winter, throwing the grappling hook to recover our buoys (Deadliest-Catch style), gazing in awe at the slowly undulating Northern Lights, and squinting desperately at a moving speck on the horizon that I was told was a polar bear.

 


Oct 2019 – Survey of high-altitude lakes

Emily joined a UNC team on a novel survey of a series of glacier-marginal lakes Khumbu region of Nepal, in order to learn more about the physics and sedimentary characteristics of high-altitude lakes in a region facing rapid environmental changes. The team included Drs. Rich McLaughlin and Roberto Camassa (Mathematics), Lauren Leave (Religious Studies), and Harvey Seim (Marine Sciences). This work was featured by the UNC College of Arts and Sciences: New Revelations in Nepal, Dec 2019.

 


Sep 2019 – Trial sampling trip on the Neuse

We teamed up with Abby, an undergraduate researcher in Biology interested in sediment records of water quality in North Carolina rivers, to collect some muddy cores in the Neuse. This was a good trial run for our lab as we gear up to survey sediments in coastal plain rivers. The water levels were low and fine sediment was patchy, but we found some satisfyingly muddy side channels for Abby’s work. Our mini research vessel worked like a champ.

 


Aug 2019 – Welcoming John Malito to the lab

John Malito joined the lab this year to work on modeling the morphodynamic evolution of the Alaskan Beaufort shelf. John is an alumni of UT Austin, and comes with field experience from the Brazos River in Texas and GIS experience analyzing the large Amazon River system. He’s definitely a Texas fan but we’re excited that he’s decided to make a new second home at Carolina. #GoHeels

 


Summer 2019 – Undergraduate research in the lab

This summer we worked with three talented UNC undergraduates – Carly joined us from Computer Science to work on sensor design and construction, Rachael Rankin joined us from the UNC IDEA program to study sediment accumulation in the White Oak Estuary, and Alan Xie lent his electronics knowledge to our sensor designs to help us move forward with DIY platforms. It was a great group and we learned a lot about technology, geochemistry, and muddy coastal systems.