Geophysical Investigation to Map Bedrock Depths and Assess Subsurface Sediment Layering Across an Active Minesite, Papua New Guinea (Q1-Q2 2017).

  • Site View.
  • Site View.
  • Site View.
  • The Boats and Crews used for the Marine Survey.
  • The MASW Survey being undertaken.
  • The ERT Survey being Undertaken.

GBG Australia undertook a geophysical investigation to map bedrock depths, determine sediment layering and resolve the shear wave velocities for those layers. The investigation composed of both Marine and Land based geophysical investigations within and around a harbour.

For this investigation Subbottom Profiling, Side Scan Sonar. Marine ReMi, Land MASW, Land Passive Seismics and Electrical Resistivity were utilised to gain as much information on the subsurface of the harbour and natural slopes as possible.

The Subbottom Profiling data was collected using a Boomer as the source within the confines of the harbour in addition to the seaward side of the harbour wall. This technique was the most widely utilised technique in this investigation as it allowed for high resolution imaging of the subsurface layering while being time efficient. As a complimentry technique the harbour was also investigated using Side Scan Sonar to image any surface features in high resolution.

Marine Passive Seismic (ReMi) investigations were undertaken within the harbour to gain informaton on the S-Wave Velocities of the shallow marine sediments with the harbour.

In conjuction with the marine component of the investigation a number of land surveys were conducted. By utilising ERT, MASW and passive seismic techniques, mapping of bedrock levels around the harbour was undertaken.

Figure 1: Site View.

Figure 2: Site View.

Figure 3: Site View.

Figure 4: The Boats and Crews used for the Marine Survey.

Figure 5: The MASW line spread out along the edge of a roadway.

Figure 6: The ERT survey being undertaken.