Unknown
PANGAEA
In:
Supplement to: Marcon, Yann; Sahling, Heiko; MacDonald, Ian R; Wintersteller, Paul; dos Santos Ferreira, Christian; Bohrmann, Gerhard (2018): Slow volcanoes: The intriguing similarities between marine asphalt and basalt lavas. Oceanography, 31(2), https://doi.org/10.5670/oceanog.2018.202
Publication Date:
2024-04-17
Description:
In 2003, the Chapopote asphalt flow was discovered in the southern Gulf of Mexico at a depth of 2,900 m. Subsequent exploration has expanded the known extent of asphalt volcanism across abyssal depths in much of this region. Aspects of asphalt flow morphology are analogous to ropy pāhoehoe flows known from eruptions of basaltic lava on land, but the timing and formation sequence of asphalt flows has been difficult to infer because limited visibility in the deep ocean makes it challenging to image large areas of the seafloor. Combining data from autonomous underwater vehicle mapping and remotely operated vehicle navigation with powerful optical mosaicking techniques, we assembled georeferenced images of the Chapopote asphalt flows. The largest image captured an area of 3,300 m² with over 15 billion pixels and resolved objects at centimeter scale. Augmenting this optical resolution with microbathymetry led to the recognition that very large asphalt pavements exhibiting highly varied morphologies and weathering states comprised a series of at least three separate flow units, one on top of another. The Chapopote asphalt volcano likely erupts during phases of intensified activity separated by periods of reduced activity. After extrusion, chemical and physical changes in the asphalt generate increasing viscosity gradients both along the flow path and between the flow's surface and core. This allows the asphalt to form pāhoehoe lava-like shapes and to support dense chemosynthetic communities over timescales of hundreds of years.
Keywords:
Center for Marine Environmental Sciences; MARUM
Type:
Dataset
Format:
application/zip, 2 datasets
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