Category Archives: Blog

Ocean Sciences Meeting 2020 (+ sunshine)

This week the Sed Lab has been in sunny San Diego at the 2020 Ocean Sciences Meeting. Conferences are a great opportunity to share research, hear fresh ideas, and learn about new opportunities. Evan and Andrea presented early results from Astoria Canyon. Robin presented posters for both her education research and the final chapter of her PhD (!!!), which examines particle aggregation and deposition in the Mekong River. Hannah gave two oral presentations, one on building a global scientific community and one on sediment dynamics in the Ayeyarwady River Delta.

Robin presenting her poster

Andrea’s presentation

Conferences are also a wonderful chance to catch up with old friends and make new friends. We hung out with Rip, Dan, and Emily, and heard about their latest research. And, most importantly, we also got a good dose of sunshine after a long PNW winter.

Evan and Rip discussing Astoria Canyon

Hannah’s presentation

Back to Myanmar

This past week the Sediment Dynamics Group was back in Myanmar! Andrea and I presented results at the International Joint Symposium at Pathein University. The focus of the symposium was “Challenges in educational development on agricultural and food resources in tropical Asia”. It was very different from the usual presentations we see! There were lots of talks about rice farming and fishing. But we met up with some old friends and made some new ones too. It’s always exciting to connect with researchers from other countries.

After the symposium we met up with Aaron and Evan, and headed back to Meinmahla Island to collect some new data. For the past 2-3 years, we’ve been investigating sedimentary processes in different types of tidal channels in the island. The island is a mangrove preserve, so we’re able to study processes in a natural environment. There are also agricultural fields along the banks of the river near the island, so we can investigate processes in a modified landscape. It’s an ideal study site! There are also lots of crocodiles, snakes, and centipedes (oh my!).

Even though it’s the rainy season we had amazing weather, and there was only one downpour. We measured water and sediment flow in the tidal channels and surveyed the island. We collected lots of videos of the river banks so that we can understand how the bank shapes change through the island. We also measured the elevation of the island and agricultural fields. It was a long week of hot work, but we got some awesome data!

CERMIT the tripod returns!

This May, the UW Sediment Dynamics Lab deployed a benthic tripod in the head of Astoria Canyon to measure canyon hydrodynamics and sediment flux. Over the summer, our tripod recorded minute-by-minute data, documenting the forces that move sediment through Astoria Canyon and into the deep water sediment record. This fall, it was time to recover our tripod from the seafloor. Andrea and Evan boarded the RV Rachel Carson, steamed out to the deployment site, and sent our tripod a signal to release its recovery float… After sleepless nights worrying about bottom-trawl fishing nets hauling away our tripod, we were relieved to discover it was intact and upright, just where we left it. Recovery went smoothly in low seas, and within the hour, our tripod was on deck. We spent a few hours cleaning sandy mud off its feet, scrubbing “biology” off of its sensors, and downloaded data from its instruments.

CERMIT the tripod, above water for the first time in four months.

This little crab was recovered with our tripod.

Although the tripod was safely on deck, our jobs were far from over–we had also set out to collect seismic profiles and sediment cores from the canyon! The USGS accompanied us aboard the RV Carson, and in collaboration with this project, they created a survey plan to map the geologic structure of Astoria canyon with seismic gear (CHIRP and multichannel). Together, the crew logged ten days of 24-hour seismic data collection, and through all that surveying, we managed to have some fun. We caught salmon and tuna, saw dozens of humpback and pilot whales, and had heated discussions over the best practices in coffee brewing. After returning to port, the USGS crew returned to Santa Cruz, reinforcements from UW’s Sed Lab arrived, and we boarded the vessel yet again for two final days of coring. Over this two day effort, the sediment lab collected 25 box cores in and around the canyon head and shelf rim, coring efficiently in spite of large swell and mechanical difficulties. 

USGS scientists deploy the CHIRP seismic package behind the boat, where it will be towed for the next week. This unit contains both the seismic source and receiver.

Aaron takes in the sunrise while steaming out to the first coring station of the cruise.

All told, three datasets were successfully collected from Astoria Canyon, and this is a big step forward in understanding what phenomena drive sediment from the continental shelf to the deep ocean. We’re excited to begin sharing results!

Aaron enjoying the little things on the ride home.

CERMIT the tripod has landed!

The sediment dynamics group has been thinking deep thoughts lately–170 meters deep, to be exact. This winter, the lab outfitted a new benthic tripod frame with instruments to quantify sediment transport in Astoria Canyon, the submarine counterpart to the Columbia River. Fast forward to this May, the lab hitched a ride on the RV Oceanus for a week and set our tripod in the head of the Canyon to record a summer of canyon events and processes. While the Oceanus pitched and rolled a few extra degrees with its heavy lift crane atop the second story, the ship and its crew were wonderful help in nestling our tripod safely into the narrow canyon head.

Both amphibious and gangly, we believe the acronym CERMIT will stick (Canyon Edge ReMote In-situ Tripod), though fans should feel free to write in with their suggestions. CERMIT is outfitted with a long list of additional acronyms: multiple ADCPs, OBSs, CTDs, an ABS, a LISST, and more. These instruments will tell us precisely where and how fast the water is moving, and the concentration of sediment along for the ride. This summer, with a bit of luck, we will catch a few of the sediment-gravity flows that travel through Astoria Canyon, and determine what caused them: earthquakes, dredging for fish, or the (less-and-less) mighty Columbia may be the culprits. This information, in turn, helps our lab and other geologists interpret sedimentary deposits nearby and across the globe.

Stay tuned for its recovery and results this September!

UW vans arrive at the Oceanus carrying the tripod (deconstructed for travel). After this photo was taken, we got to work assembling it in the sunshine!

After construction on the dock, a crane brings the tripod aboard the Oceanus.

On the morning of deployment, the tripod is moved under the A-frame for lowering.

The tripod sneaks overboard, with everyone thankful for small swell.

Goodbye for now, CERMIT!

Science Writing for Diverse Audiences

This quarter, I’m up at Friday Harbor Labs teaching Science Writing for Diverse Audiences. As a class, we are exploring effective ways to read, write, and commicate science – all the way from peer-reviewed articles to op-eds and blog posts.

Friday Harbor is an excellent place to find inspiration to write. This past week, we headed out on the R/V Centennial to explore ecosystems around the island. We dug through sand and shell hash to get our hands on wriggly sand lances. We sifted through dredge material to find slime stars and anemomes. And, we gazed through microscopes to spot a myriad of zooplankton. The students’ enthusiasm clearly demonstrated their curioisity and love of natural science. We practice effectivelly describing our experiences with thoughtfully structured sentences, active verbs, and descriptive adjectives – skills that are needed to write well-received science articles.

Students explore rocks and organisms pulled up from the seabed.

Zooplankton under a microscope were displayed for all of us to see and discuss.

Students practice describing what they see in words.

But, this group of students has self selected to be here, and we’ve discussed that not everyone shares our views of science. Perspective colors how science is performed and perceived. Even within this self-selected classroom, students represent diverse views of science. As individuals, we tend to see science as beautiful and inviting. But, our families and cultures tend to see science more as a means to financial gain, often with devious conotations.

Students describe their own, their family’s, and their identified culture’s perception of science.

So, to add to our list of writing skills, we also practice how to frame our writing to fit our audience’s perspective. Research shows that scientists are often viewed as trustworthy, but cold. So, to present ourselves as authors that are both competent and warm, we practice contructing narrative arcs and adding humor and personality.

The quarter isn’t even half way over, and the students  are already better writers. Their arguments are persuasive, their desciptions are vivid, and their confidence is rising. I expect to see great things from this group. After all, science is often not driven by the best scientists, but instead by the best communicators.

Written by Robin McLachlan

Cooking Myanmar Food in Seattle!

Our lab has an ongoing research project examining sediment dynamics within the mangrove forests and distributary channels of the Ayeyarwady Delta in Myanmar.  During each of our field efforts we are enchanted by the food of Myanmar, which has hints of Thai, Chinese, or Indian influence, but is ultimately a cuisine all its own.

After tracking down a number of hard-to-find ingredients, we gathered to create our Burmese feast right here in Seattle.  In the end we made Yinmabin-Chowle Kyattha (chicken curry with okra), julienne green beans with garlic, Bottle gourd soup, and Shrimp Tom Yum Goong Soup.  This last dish is actually a Thai classic, but we made it as an homage to our favorite Thai Restaurant in all of Myanmar, the famous “G7 Gym and Restaurant” in the city of Pathein, located on the westernmost distributary of the Ayeyarwady Delta.

While we can’t claim to have mastered any of these dishes, it was fun to bring a bit of Myanmar cuisine to friends and family back here in Seattle.

Mesophotic reefs at the Amazon River mouth: an inconvenient truth

Did you know that there’s a reef near the mouth of the Amazon River?

Reefs off the Amazon River mouth at ~180 m depth, close to the Brazil-French Guiana border. They’re, thriving from abundant nutrients but with less light and more suspended sediment.

Our group has recently been involved in the study of the mesophotic reefs that are at the outer shelf where the Amazon River discharges into the Atlantic Ocean. Mesophotic means that the reef is composed of organisms that use photosynthesis to grow and organisms that don’t need light to grow.

Although evidence of a reef system in the region has been presented since the ‘70s, a simplistic view remained that the Amazon River plume prevented reef development. The existence of this reef system is now incontestable, due to results from scientific cruises performed in cooperation with the Brazilian Navy in 2014 and 2017, as well as with Greenpeace, in 2017 and 2018.

The  area is also facing potential threat from new oil & gas exploration, resulting in conflicting interests between environmental conservation and exploration of natural resources. Although oil companies themselves recognize the reef existence and its relevance, there have been unscrupulous people trying to convince the authorities and general public that the reef does not even exist (aka fake news).

Our mission is to better understand this reef system and how it survives so close to the Amazon River plume. The plume carries much suspended sediment, which decreases the light reaching the sea bed. We are working to understand the dynamics of suspended sediments of the Amazon River and the sedimentary and oceanographic mechanisms that enable this reef system to exist.

The Brazilian branch of the Sediment Dynamics Group

Nils and family at Drumheller Fountain, UW-Seattle

Nils outside the UFPA campus in Braganca.








Nils and his family have returned to Bragança, but they’re keeping in touch! Here’s his news on settling back into life and work in Brazil:

After spending one very pleasant and fruitful year at UW-Seattle, I’m back home in Bragança, Brazil where I work at the UFPA campus. Right now, the challenges for science are bigger than ever in Brazil, but the scientific tools I brought from UW are really helping me through. One major challenge is the drastic decrease in public funding for research for all disciplines and levels. I’m overcoming this impediment by taking advantage of all the data collected along the lower Amazon River, Tapajós and Xingu tributaries, as well as along the Brazilian Amazon mangrove belt and at the Amazon shelf. All this data is a result of large cooperative fieldwork efforts during the last five years. This backlog assures us long hours of data analysis at the lab and even more time trying to understand and publish the results. We have been making good progress so far, with the recent publication of papers in journals such as Estuarine, Coastal and Shelf Science; Earth Surface, Processes and Landforms; and Geochimica et Cosmochimica Acta. Several papers are under review as well and are coming out soon.

Stay tuned to our blog to hear more from Nils and get notifications for his upcoming publications!

Recent field work in Myanmar

The lab just finished a short, two-week trip to Myanmar. The primary goal of this trip was to discuss research with our Burmese colleagues. We participated in a conference at Yangon University, where we also heard presentations from American colleagues who have been working in the Gulf of Martaban.

Aaron preparing to discuss results with collaborators from VIMS and Yangon University

Next we presented our results at Pathein University, where we also led a data processing workshop and a short research trip on the Pathein River.

Filtering water samples doesn’t have to be boring!

We also managed to fit in two days of field work on the Yangon River with Myanmar Maritime University. During the winter period of dry weather, the river discharge decreases, and the amount of sediment in the water increases. During our previous trip, in March 2018, we measured as much as 15 grams of sediment per liter and our acoustic instruments didn’t work! This time, we came prepared for very high sediment concentrations. We were able to track the high concentrations during a full tidal cycle and also measure the river discharge. It’s very exciting to see such an extreme riverine environment!

Large vessels using the Yangon River. This one parked in the middle of our sampling location.

Improvised raft for measuring water flow.

Our Yangon River crew