The Science of Dune (Psychology of Popular Culture) by Kevin R. Grazier

Author:Kevin R. Grazier [Kevin R. Grazier]
Language: eng
Format: epub
ISBN: 9781935251408
Publisher: BenBella Books
Published: 2007-12-11T00:00:00+00:00

The Big Picture: Thresholds, Patterns, and Networks

One emerging field of science which attempts to predict events taking place over large time scales is threshold and pattern dynamics. Rather than looking at everyday events like weather, it examines uncommon and important events such as volcanic eruptions, tsunami, algae blooms, and disease epidemics. These types of events occur suddenly, but they have telltale signs of buildup which often go unnoticed because they take place over long periods of time. Threshold and pattern dynamics attempts to model the factors driving these events using mathematics and computers to identify critical thresholds where the system will shift dramatically. Not only must scientists recognize which factors influence an event, they must develop methods to observe and measure these factors. Then, the next challenge lies in identifying patterns in the observations which indicate where a future threshold will be crossed.

This new field started with efforts to predict earthquakes. For many years, teams of scientists have been collecting data from seismic sensors in earthquake-prone regions. Joining this data with information about geological makeup of the region, they are able to create computer models of stress buildup and movement along fault lines. The enormous number of calculations required for this modeling can only be done on very powerful and fast computers. Today’s supercomputers operate in the terabytes (TB) range. (1 TB equals 1,024 gigabytes or over 1 million megabytes. In comparison, the average home computer has 512 megabytes to 1 gigabyte of RAM.) Scientists use this computing power to run detailed computer simulations of earthquakes, such as the TeraShake simulations run by the Southern California Earthquake Center. Using data on how different types of soil and bedrock move in earthquakes of varying depth and magnitude, and how seismic waves travel through these rocks and soils, TeraShake predicted the widespread effects of a future earthquake occurring along the San Andreas Fault. (TeraShake required 1 TB to run, took five days, and output 47 TB of data. It ran on DataStar at the San Diego Supercomputer Center.)

Studies of threshold and pattern dynamics can provide the key information for making these types of projects true earthquake predictors—the key is where and when an earthquake is likely to happen. To do this, a team at the University of California, Davis has developed simulations of entire fault systems, showing the geologic activity over thousands of years. The program simulates the constant rate of tectonic plate movement along a fault, which causes stresses to build up until the rocks slip, triggering an earthquake. By identifying the threshold at which the stress becomes too great, this program can predict when and where an earthquake will occur. Due to the difficulty of modeling complex systems, current simulations can’t yet predict exact times and locations of earthquakes. However, they can show that an earthquake is likely to occur in one of a small number of areas and within a specific window of time. The geologic time scale is very long compared to human life, but as the methods

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