English Deutsch Français Italiano Español Português 繁體中文 Bahasa Indonesia Tiếng Việt ภาษาไทย
All categories

How does seismic evidence help?

2007-02-25 08:42:13 · 3 answers · asked by :] 1 in Science & Mathematics Earth Sciences & Geology

3 answers

By studying the records of earthquakes worldwide, seismologists have been able to determine how long it takes seismic waves to pass through the Earth, depending on the path that the wave travels. From this data, they can calculate how seismic-wave velocity changes with depth. The data reveal that there are specific depths inside the Earth at which velocity abruptly changes and waves bend-these depths are called seismic discontinuities. Seismic discontinuities divide the Earth's interior into distinct shells; within a shell, seismic wave velocity increases gradually, and waves bend gradually, but at the boundry between shells, wave velocity changes suddenly and the waves bend. The understanding of the two types of seismic waves; P-waves and S-waves, and how they react differently in a given material and composition, also helps us to understand how the different layers of the Earth's interior are constructed.

2007-02-25 08:58:53 · answer #1 · answered by eiscubes 2 · 0 0

Eathquakes produce diverse kinds of waves. P waves (or compressional waves that are resembling sound - the wave fluctuates parallel to the route of propagation) S waves (or sheer waves that are resembling a stone on a pond - the wave fluctuates perpendicular to the route of propagation). those waves commute by the Earth the diverse parts of the Earth at diverse speeds, are pondered in diverse way and absorbed in diverse recommendations. Seismologists can study those conventional and predictable houses of P and S waves to make certain the interior structure of the Earth. It does no longer advise its acceptable, notwithstanding it does provide an precise theory of massive scale structure.

2016-12-04 22:45:35 · answer #2 · answered by ? 4 · 0 0

p and s waves react differently when passing through different material. p and s waves are produced by earth quakes and are recorded by sensors all over the earth in studying the time it takes to reach certain stations and which waves reach you can build up a model of the earth in terms of density and fluid behavoiur. you vcan go into great depth with pkkk and pikik waves etc but im sure that is more advanced to what you need

2007-02-25 08:48:56 · answer #3 · answered by Kev P 3 · 0 0

fedest.com, questions and answers