Measuring a Moving Earth - Tectonic Plate Displacement Vocabulary

Vocabulary flashcards defining key techniques and concepts used to measure modern tectonic plate displacement and motion.

Velocity (Plate Displacement)

The rate of tectonic plate movement over time, calculated using the formula $\text{Velocity} = \frac{\text{displacement}}{\text{time}}$.

GNSS / GPS

Global Navigation Satellite System / Global Positioning System; a system that receives timed signals from several satellites to calculate exact ground position and track 3-D movement (east–west, north–south, and up–down).

InSAR

Interferometric Synthetic Aperture Radar; a technique that compares radar signals from satellite images taken over the same area at different times to map wide-area ground movement toward or away from the satellite.

VLBI

Very Long Baseline Interferometry; a technique where radio telescopes observe the same distant quasar and compare signal-arrival times to measure changes in distance and direction between telescopes.

Satellite Laser Ranging

A technique that sends a laser pulse to a satellite reflector and times the returning light to calculate the precise distance between the ground station and the satellite.

Seismic Monitoring

The use of seismometers to record P waves, S waves, and surface waves from earthquakes to locate sudden fault movements and identify active boundaries.

Geological Evidence

The study of displaced landforms, fault layers, rock ages, and magnetic patterns to record past fault movement and long-term seafloor spreading across thousands or millions of years.

Global Reference Frame

A precise global coordinate standard maintained and improved through techniques like VLBI and Satellite Laser Ranging to track large-scale plate motions globally.