Geoscience Australia Survey 267, Post Survey Report: Testing Natural Hydrocarbon Seepage D

The Yampi Shelf in northwestern Australia's Timor Sea was surveyed from March 3 to 18, 2004 aboard the vessel Parmelia K. Geoscience Australia conducted this marine survey to test techniques for detecting natural hydrocarbon seepage in a known active region. Direct observations of seepage plumes, gas bubbles, and associated biotic zones were made using echosounders, sonar, a fluorometer, and sediment sampling.

Use Cases

• Validate remote sensing seepage detection algorithms based on direct observational data from echosounders and side-scan sonar.
• Model tidal influences on seepage activity based on observations of activity variation with low and high tide.
• Correlate seepage sites with geological features based on data associating seeps with hydrocarbon-related diagenetic zones (HRDZs) and pockmark fields.
• Analyze marine biotic distribution patterns based on grab and dredge samples suggesting seeps are zones of preferential macro-biotic distribution.

Strengths

• Provides direct observational validation of hydrocarbon seepage, which was previously only interpreted through remote sensing.
• Survey employed multiple complementary techniques including multi-beam bathymetry, acoustic Doppler current profiling (ADCP), fluorometry, and sediment sampling.
• Focused on a known region of intense and widespread hydrocarbon seepage, the Yampi Shelf.

Limitations

• Survey length was curtailed by unfavourable weather conditions associated with tropical cyclones Evan and Fay.
• Significant down-time was introduced through poorly functioning leased equipment and a lack of staff experience.
• Gravity coring was largely unsuccessful due to carbonate hard-grounds over the seepage sites.
• Column-level documentation is absent; field semantics must be inferred after download.

Provenance

Source

Australian Ocean Data Network

Collection Method

Marine survey aboard the Parmelia K, utilizing echosounders, side-scan sonar, a towed fluorometer, ADCP, multi-beam swath bathymetry, and sediment sampling with grab, dredge, and core.

Time Range

March 3 to 18, 2004

Freshness

Last updated 2026-05-04 23:40:35.298199; freshness should be verified.

Geography

Yampi Shelf, Timor Sea, northwestern Australia