Help From Above, Part Two: Creeping Towards Earthquake Prediction

The state of California is characterized by, among other colorful attributes, its natural hazards.

Earthquake risk provides the most obvious example. Landslides are another substantial risk for the state. Intensive human settlement doesn't mix that well with extremely active geologic processes. So constant measurement of myriad dynamic physical features is a must. When it comes to seismic activity (where event predictability remains an out-of-grasp brass ring), the more data available the better.

As featured in the June 29 edition of the San Francisco Chronicle, science editor David Perlman presents a look into the efforts of NASA scientists to detect extremely small rates of change.Through the use of extraordinarily sensitive radar equipment fixed to the belly of aircraft, geophysicists are gathering extremely fine-resolution information throughout the state, especially on the all-important San Andreas and Hayward faults.

How fine is fine? To the millimeter, quite literally. And from an elevation of 45,000 feet, no less.Analysis of same-place landform geometries over time means scientists can follow changing rates of creep in hill slopes, and in the relative movement between areas sitting on opposite sides of fault lines.

Detection of changes in annual rates of movement that are measured in millimeters is of great value in identifying areas at greater relative risk for landslides or seismic events, and in determining whether such events are more likely to occur sooner rather than later.