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

Ragay Gulf in the Philippines archipelago contains vertical measurements of methane in the water column, revealing mid-water and bottom-water plumes between 80 and 100 meters thick. The dataset, sourced from the Australian Ocean Data Network, includes average methane supersaturation of 206±16.5% in surface waters and estimated sea-air fluxes averaging 101 nmole.cm-2.y-1. These measurements suggest naturally occurring thermogenic methane seepage from the sea floor contributes to atmospheric greenhouse gases.

Use Cases

• Modeling methane transport from seafloor seeps to the atmosphere based on vertical plume distribution data.
• Comparing natural fossil methane fluxes from this region to anthropogenic or biogenic fluxes measured elsewhere.
• Investigating the relationship between methane anomalies and steep temperature-depth gradients in semi-enclosed basins.
• Assessing the contribution of thermogenic methane from marine sediments to global greenhouse gas budgets.

Strengths

• Includes specific quantitative measurements: average methane supersaturation of 206±16.5% and estimated sea-air flux of 101 nmole.cm-2.y-1.
• Describes spatially localized features: methane plumes persisting 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 solely on Ragay Gulf.

Provenance

Source

Australian Ocean Data Network

Collection Method

Vertical distribution measurements in the water column of Ragay Gulf.

Freshness

Last updated 2026-06-04 05:38:20.533236; freshness should be verified.

Geography

Ragay Gulf, Philippines archipelago.