Overview

Geophysics has been a core science discipline at Berkeley Lab for over 40 years, predating the 1977 formation of the former Earth Sciences Division (ESD). During the world energy crisis of the mid-1970s, keen interest arose in finding alternative sources of energy. A number of UC Berkeley/Berkeley Lab scientists began exploring the possibility of finding geothermal energy sources using advanced geophysical techniques. This interest led to geothermal field explorations in Northern California, Nevada, and Mexico. Such projects soon expanded into geophysical studies of potential nuclear waste storage sites, and were the beginnings of ESD.

Since then, in addition to continuing and expanding its geothermal studies (in response to the abiding interest in locating and developing alternative energy sources), the Geophysics Department has expanded its mission and now conducts work on a wide variety of geotechnical problems for energy and environment. This work includes remediation projects at contaminated DOE sites, CO₂ sequestration studies to mitigate the impacts of global warming, development and testing of new geophysical technologies for fossil energy and mining applications, geological and man-made hazard investigations, and basic research in geophysics. In these endeavors, our geophysicists employ subsurface modeling and imaging, and laboratory and field-scale studies for varied applications, including:

• Mapping contaminant transport near the surface of polluted areas
• Identifying geothermal fluids, oil and gas deposits, and CO₂ plumes
• Investigating earthquake and volcanic hazards
• Locating unexploded ordnance (UXO).

Today, the Geophysics Department resides within the Earth and Environmental Sciences Area (EESA) where scientists, postdocs, research associates, and graduate students carry out a wide range of advanced research in fundamental and applied geophysics. The Geophysics Department is currently driven by two primary objectives.

• One is to advance geophysical approaches for quantifying subsurface properties, including fluid properties, saturation, porosity, pore pressure, permeability, and in situ stress, from laboratory studies and field measurements at the earth surface and in boreholes.
• The other is the development of technologies for subsurface resource access and monitoring, such as seismically enhanced oil recovery, geomechanics-based subsurface-permeability enhancement, and microearthquake-based reservoir monitoring.

Recent Activities

In 2015, the Geophysics Department hosted a series of forums to bring together its members, other invited guests, and other interested individuals to talk about the various seismic modeling software programs and electromagnetic modeling codes used in the Department and their applications. Attendees gained overall knowledge of Department capabilities and shared best practices and latest developments.

Core Capabilities

The focus of this research area is the development of innovative geophysical hardware and methodologies for subsurface imaging and monitoring, such as high-resolution borehole tomographic tools (radar and seismic), and micro-earthquake monitoring systems.

Research in environmental geophysics area combines the disciplines of geophysics, hydrogeology, statistics, and biogeochemistry to develop new approaches for characterizing shallow subsurface properties and for monitoring complex processes associated with natural or induced subsurface perturbations.

Geomechanics is concerned with the elastic and/or poroelastic response of earth materials, typically in a scientific or engineering setting that involves fluids such as water or oil stored in earth reservoir.

Our subsurface imaging research is now focused on combining multiple types of geophysical data sets to better quantify the subsurface and reduce ambiguity. The degree to which joint images of geophysical attributes can be used successfully to infer rock properties (fracture orientation, fracture density, temperature and fluid saturations) from geophysical attributes is also an active area of research. Complementing this imaging capability is our robust computational capability, the challenge for which is to develop accurate and efficient computer codes capable of modeling the seismic and electromagnetic response in complex geologic media.

The relationships between geophysical attributes (such as seismic velocities and attenuation, electrical conductivity, and dielectric constant) and rock properties (such as porosity, permeability, and fluid saturation) are provided by rock-physics measurements and/or theoretical understanding.