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

Ragay Gulf in the Philippines archipelago contains vertical methane measurements in a semi-enclosed basin. The data includes mid-water and bottom-water methane plumes between 80 and 100 m thick, confined to depths of 100-220 m, with an average surface supersaturation of 206±16.5% and an estimated minimum sea-air flux of 101 nmole.cm-2.y-1. The dataset is provided by the Australian Ocean Data Network and was last updated in June 2026.

Use Cases

• Modeling methane transport from seafloor seeps to the atmosphere based on described vertical plume distributions.
• Comparing natural fossil methane fluxes from this region to anthropogenic or biogenic fluxes measured elsewhere.
• Analyzing the relationship between methane concentration and thermocline structure based on the temperature-depth gradient mentioned.
• Estimating regional contributions to atmospheric greenhouse gases based on the reported sea-air flux calculations.

Strengths

• Includes specific quantitative measurements: average methane supersaturation of 206±16.5% in the top 5 meters at nine locations.
• Provides calculated environmental metrics: estimated minimum sea-air methane flux of 101 nmole.cm-2.y-1 with a provided range.
• Describes detailed spatial characteristics of methane plumes, including thickness (80-100 m) and depth confinement (100-220 m).

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 single gulf.

Provenance

Source

Australian Ocean Data Network

Collection Method

Vertical distribution measurements of methane in the water column.

Freshness

Last updated 2026-06-27 21:10:23.676869; freshness should be verified.

Geography

Ragay Gulf, Philippines archipelago