Methane Anomalies in Ragay Gulf Seawaters: Vertical Distribution and Atmospheric Flux

Vertical methane distribution in the Ragay Gulf, Philippines, reveals unusual mid-water and bottom-water plumes 80-100 m thick. The average methane supersaturation in the top 5 meters of sea water at nine locations was 206±16.5%, with an estimated minimum sea-air flux of 101 nmole.cm-2.y-1. This dataset, hosted by the Australian Ocean Data Network, was last updated in April 2026.

Use Cases

• Model methane transport from seafloor seeps to the atmosphere based on vertical concentration profiles.
• Compare natural fossil methane fluxes from this region to anthropogenic or biogenic fluxes measured elsewhere.
• Investigate the relationship between methane plume location and steep temperature-depth gradients described in the data.
• Estimate regional greenhouse gas contributions from oceanic sources using the provided sea-air flux calculations.

Strengths

• Includes specific quantitative measurements: average methane supersaturation of 206±16.5% and estimated minimum sea-air flux of 101 nmole.cm-2.y-1.
• Describes distinct, persistent geophysical features: methane plumes 80-100 m thick over kilometre-scale distances.
• Provides geochemical context suggesting a thermogenic origin for the methane anomalies.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.
• Data may reflect geographic bias inherent to data_gov_au, focusing on a specific gulf in the Philippines.

Provenance

Source

Australian Ocean Data Network

Collection Method

Vertical measurements of methane concentration in the water column at multiple locations.

Freshness

Last updated 2026-04-16 08:46:09.138778; freshness should be verified.

Geography

Ragay Gulf, Philippines archipelago.