Seismogram on smoked paper
from the Measurements page in Quake Basics

The squiggle is a record of a quake that struck near the town of Coalinga, in centeral California, in 1983. The earth's movement is recorded on paper that is covered with a layer of smoke particles. When the needle moves across the paper, it scratches off bits of smoke, recording the motion with very fine details.
Photo: Adrian Van Allen



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