Materials courtesy of Scripps Institute of Oceanography.
When scientists set out to study the history of a marine area, they often turn to push cores. These are clear tubes, typically between 2 and 6 feet long, that are carefully pressed into the seafloor by an underwater robot called a submersible, deployed from the main research vessel. The method offers an uninterrupted snapshot of the seafloor’s history. By studying the layers and using techniques like carbon dating, scientists can piece together the timeline of volcanic eruptions, earthquakes, and changes in marine life.
From “Ocean Floor Sediments” (CliffsNotes): The ocean floor is made up of three primary types of sediment: terrigenous, pelagic, and hydrogenous. Terrigenous sediment, which comes from the land, is usually deposited on the continental shelf, rise, and abyssal plain, carried by rivers, wind, ocean currents, and glaciers. Pelagic sediments consist of tiny clay particles and the microscopic remains of marine life that fall slowly to the ocean floor. Some of these organic materials—called calcareous or siliceous "oozes"—are thick, gooey, and rich in marine life. The clay (and sometimes volcanic ash) is blown from land by the wind and settles on the ocean’s surface. Hydrogenous sediments, like manganese nodules, are formed by minerals precipitating directly from seawater on the ocean floor.¹
In collaboration with the Scripps Institute, I set out to explore innovative ways to apply oceanic sediments in art, aiming to continue the story of the seafloor by giving these materials a new voice and inspiring a more public focus. Through this process, we also observe how the materials transform under heat, gathering insights that may prove valuable in the future.
Above: Push core sampling at the deep-sea floor. Image showing aluminum tube push cores used alongside polycarbonate tube push corers (HOV Shinkai 6500, Dive #1553, 5719 m depth, 3380.2359° N, 14580.7300° E; ROV Hyper-Dolphin, Dive #2041, 1548 m depth, 34854.8968° N, 138839.0413° E).²
Above: Researchers collecting core samples with ROV SuBastian off the coast of Guam, Schmidt Ocean Institute.³
As ceramicists, we are intimately familiar with terrestrial materials. Clays are mined from regions around the world, each mineral combination influencing the final ceramic product. Wild clay artists like myself work directly with freshly foraged materials, often understanding their properties through basic research and in-studio testing. Marine sediments, however, present a different challenge. I have found no precedent in the artistic community for how to approach these materials—no roadmap to understand their melting points, water retention, plasticity, or the changes they undergo at high temperatures (up to 1260°C / 2300°F).
Above: Marine sediment slip tests on porcelain tiles.
Knowing that the terrestrial clays in my region (Southern California and Baja) are typically low-fire earthenware, I began experimenting with marine sediments at low temperatures, starting at 800°C, applied as slips on white mid-range porcelain tiles. Some materials behaved similarly to clay, while others, particularly the calcareous oozes, crumbled, lacking any plasticity and simply resting as a loose powder on the tile. As I gradually increased the firing temperatures, familiar red clays exhibited their own unique transformations—flaking off at 1000°C and melting into a dark iron sludge by 1260°C. The calcareous oozes, however, offered the most intriguing results. These samples, derived from the endoskeletal remains of Thecosomata (or "sea butterflies"), demonstrated striking changes.
Thecosomata – Sea butterfly from the Pteropoda family. Image taken by Alexander Semenov, Cold Water Project.⁴
"Pteropods are foundational to the oceanic food chain—sea butterflies, sea snails, and sea angels. Their endoskeletal remains, which settle as dust on the ocean floor, are used in works like Still Waters and Aloha Aina, where they appear as blue streaks on porcelain. This pure calcium carbonate remains chalk white through much of the firing process, but at 1200°C, it undergoes a transformation, blooming into a brilliant ocean blue. This color, rare in nature and almost impossible to replicate in geological work, is a reminder of the beauty found in the most unlikely places. Before working with pteropod dust, I had never felt such a deep connection with the remains of living creatures in my clay practice.”
Above: Testing and application of pteropod dust on "Still Waters."
To understand these transformations more fully, I’m collaborating with the team at Scripps to analyze the materials at each firing temperature. Using a scanning electron microscope and an X-ray fluorescence (XRF) analyzer, we’re studying the molecular changes that occur as the materials are subjected to heat.
Below: Snippets from the ceramic studio and Scripps geological lab, 2023-2024.
Above: Data sheet of 8 marine sediments provided by Scripps, tested in the Olla Ceramic Studio.
Above: Precipitating salts from giant kelp (Macrocystis pyrifera) before being burned down to ash, ready for rinsing.
Above: Scanning test tiles in Scripps' XRF analyzer.
Below: A late-night studio session applying raw marine sediments, kelp ash, and oceanic clay to a piece.
The red clays used in Red Tide show traces of past organisms, highlighted in yellow against the deep maroon backdrop after firing. These sediments are full of surprises—gifts that reveal themselves with each viewing. They cannot be replicated; they are specific to a place and time, retrieved only after the labor of countless scientists. I am honored to give these materials a second life, advocating for their origin through art.
Above: Pieces from this collection displayed at the new Scripps Marine Conservation and Technology Facility in November of 2023.
2. Tsuchiya, Masashi, et al. “Sediment Sampling with a Core Sampler Equipped with Aluminum Tubes and an Onboard Processing Protocol to Avoid Plastic Contamination.” ResearchGate, Nov. 2019, www.researchgate.net/publication/337003750_Sediment_sampling_with_a_core_sampler_equipped_with_aluminum_tubes_and_an_onboard_processing_protocol_to_avoid_plastic_contamination.
3. Schmit Ocean Institute, "One Step Closer to the Sea Floor." Aug. 2016, https://schmidtocean.org/one-step-closer-seafloor-new-underwater-robotic-vehicle-tested-guam/
4. Pteropoda Image Credits: Semenov, Alexander. Cold Water Science, coldwater.science/project/pteropoda.
