Dislocation in Elastic Halfspace Model of the Earthquake18

Dislocation in Elastic Halfspace Model of the Earthquake18...

Info iconThis preview shows pages 1–6. Sign up to view the full content.

View Full Document Right Arrow Icon
12.005 Lecture Notes 18 Dislocation in Elastic Halfspace Model of the Earthquake Cycle Interseismic: Slip below depth D Figure 18.1 Coseismic: Region above D “catches up” Figure 18.2 X/D Strain Displacement -15 -10 -5 5 10 15 y X/D -3 0 ε xy 3 -3 -15 -10 -5 5 10 15 0 X/D 3 y X/D ε xy Figure by MIT OCW. Figure by MIT OCW.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Displacements from Earthquakes, Fault Slip, etc Consider a strike-slip fault with displacement S, independent of depth – A screw “dislocation” – i.e., a slip discontinuity. Original ring (dashed) becomes helix (solid). Figure 18.3. Section across a mathematical model of a transcurrent fault. “Dislocations” are used to describe defects in crystals, as well as fault motions. A crystal disrupted by a screw dislocation is shown in the figure below. 1 2 D D i s l o c a t n x S/2 S/2 Fault displacement S S u r f e x 3 x 2 x 1 Figure by MIT OCW.
Background image of page 2
Figure 18.4. A screw dislocation in a cubic lattice constitutes a deformation that is out of the plane of atoms illustrated. The two atoms denotes by solid circles are essentially part of a second plane. The Burgers circuit indicated by the numbered
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 4
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 6
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: steps naturally moves into this second plane. Therefore in order to close the circuit the Burgers vector b* must be perpendicular to the plane of atoms shown. Types: Figure 18.5 7 6 5 4 3 2 1 10 b * 8 9 Screw Edge Figure by MIT OCW. Figure by MIT OCW. Figure 18.6 Side view of an edge dislocation in a cubic lattice. Dislocation motion helps crystals deform (don’t all have to slip at one time). Also helps Earth deform! Figure 18.7 A dislocation. b * 2 1 3 4 5 10 9 6 7 8 1 2 3 4 5 10 9 8 7 6 C D E A S B Figure by MIT OCW. Figure by MIT OCW. Figure 18.8 Upper group: Slip by propagation of an edge dislocation EE. Lower group: Slip by propagation of a screw dislocation SS. E C A b b B E E E S S S S B A C Figure by MIT OCW. Figure 18.9 Displacement as a function of distance from a transcurrent fault. 1 2 2 4 6 8 10 Displacement (meters) Distance from fault (km) NE Figure by MIT OCW....
View Full Document

This note was uploaded on 10/25/2010 for the course MIT Geodynamic taught by Professor Ywn during the Fall '10 term at MIT.

Page1 / 6

Dislocation in Elastic Halfspace Model of the Earthquake18...

This preview shows document pages 1 - 6. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online