Our field experiments
Up to 2023 Coastal Carbon has taken part in two large scale field experiments. We set up a measurement campaign to the green olivine beaches in Hawaii (2022) and did measurements at the back basalt coastline of Iceland.
Olivine weathering in Hawaii
The green sand Papakōlea beach in Hawaii is one of only five natural olivine beaches in the world. The beach is situated in an old cinder cone that was formed by a volcano eruption almost 50 000 years ago, and olivine has been weathering in the area ever since. Today, the sand on the beach and in the water contains about 40% olivine. This makes the area ideal for studies of olivine weathering in a natural setting, as well as evaluation of long-term effects of the process.
In the summer of 2022, we visited Papakōlea to measure the dissolution rate of olivine in these natural sediments. We used flow-through incubations in which sediment was packed into containers, through which water was pumped to simulate waves and tidal flows. We sampled the water at regular times to measure the accumulation of olivine dissolution products and calculate how rapidly the olivine is weathering.
The field work in Hawaii was conducted in collaboration with Vesta.
Basalt weathering in Iceland - DEHEAT
Iceland is known as the land of ice and fire for a reason. It is a volcanic island comprised largely of basalt. The seafloor on the continental shelf continuously receives basalt from Iceland’s famous black basalt beaches. In the summer of 2023, we set sail for the southern coast of Iceland with the new Belgian research vessel Belgica to study basalt weathering on the seafloor.
We used benthic chamber landers to measure weathering directly on the seafloor and collected samples for experiments on the ship and analysis at home. The results from the field measurements will be used together with state-of-the art numerical models to investigate silicate weathering.