Curtin researchers are finding ways to combine seismic and electromagnetic data to generate highly detailed pictures of the subsurface. These pictures are then used by mineral explorers searching for new mega-deposits of gold, copper, lead, zinc and other commodities at varying depths below the surface.<\/p>\n
For the past century, the search for oil and gas has relied primarily on seismic reflection. More recently, they have deployed electromagnetic methods in deep ocean settings. Seismic reflection involves the creation and measurement of seismic vibrations in the earth as a means to map the earth\u2019s subsurface, while electromagnetic methods, such as magnetotellurics (MT), measure distribution of electrical and magnetic fields in grids of sensors to reconstruct electrical properties in the earth, and in doing so, gain insight to what lies beneath.<\/p>\n
Vastly different, each technique has been treated quite independently. However, according to Curtin Associate Professor Brett Harris, there are clever ways to combine the technologies to achieve an improved representation of subsurface geology with important application in hydrocarbon industries, groundwater, hydrothermal and minerals industries. These \u201ccooperative inversion\u201d methods will be needed as Australia explorers transition to searching at much greater depths for new massive tier one mineral deposits.<\/p>\n
\u201cSeismic is tremendous in that it\u2019s accurate and it can usually identify boundaries of a subsurface layer or even mineral deposit,\u201d Harris explains.<\/p>\n
\u201cThe problem with electromagnetic technology is that it gives a low-resolution image of the subsurface. So instead of seeing the presence of ore minerals in an area, you just see this big hairy blob.<\/p>\n
\u201cHowever, when you couple the power of the seismic with the electromagnetism, you can locate a target in a specific subsurface geological horizon.\u201d<\/p>\n