|We are currently developing, jointly with Scripps Institution of Oceanography (SIO), high-frequency recording seismic instruments to enable shallow sub-seabed imaging, at the high-resolutions necessary to investigate the fine-scale detail of the sediment cover and the nature of the fluids within it. Not only does such an approach enable imaging of the properties and characteristics of oil and gas reservoirs, it also enables investigation of methane “ice” accumulations located in the shallower areas on margins of continents, and how the gas released from them vents to the surface. Massive releases from such accumulations are hypothesised to be an influencing factor in periods of rapid climate change, but the mechanisms involved remain poorly understood.
Similarly, we are also in the planning stages of a project to build an instrument capable of recording, during a single deployment, different types of geophysical data at the same time. The scientific rationale for such an approach is that it ensures both data types are recorded along the same transect and under the same temporal geological conditions.
This is necessary to optimise data for simultaneous and joint analysis, which is at the forefront of current developments in data modelling approaches. A combined analysis of seismic and electromagnetic data acquired in the same place at the same time, provides a greater understanding of sub-surface roc characteristics and a greater confidence in the resulting model’s accuracy.
Such acquisition will require significant and technically challenging instrument development to enable, for example, the amplification and digitisation of extremes of signal characteristics as demonstrated by seismic and electromagnetic sensor outputs. An added value to such a development is that it reduces the number of ship days required for any particular multiple data type experiment, since instruments will only need to be deployed and recovered once.
Recently we have been approached to undertake long-time-frame recording of global earthquakes which are used to image the structure in the earth’s deep interior, to support a number of continent-scale multi-nation programmes.
Undertaking such data acquisition will require: