logging in or signing up 01 13 05 Andersonian Heng Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINTLite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 270 Category: Entertainment License: All Rights Reserved Like it (0) Dislike it (0) Added: November 15, 2007 This Presentation is Public Favorites: 0 Presentation Description No description available. Comments Posting comment... Premium member Presentation Transcript The last of the CIRCULAR GRAPHS which will HAUNT YOU ALL QUARTER: The last of the CIRCULAR GRAPHS which will HAUNT YOU ALL QUARTER January 13, 2005 [Many thanks to H. Bob]Stress - Real Time: Stress - Real TimeSlide6: Map of global seismicityDefinitions: FRICTION: Definitions: FRICTION Same as sliding blocks from physics class (kinetic friction) Determines slope of Coulomb failure envelope For unconsolidated materials, m = angle of internal friction = angle of repose. For rocks, m = coefficient of friction of sliding surfacesDefinitions: COHESION: Definitions: COHESION For whole rocks: C = breaking strength. For broken surfaces: C = static friction. For unconsolidated sediment: C = ZERO. Like “static friction” from physics class No shear stress on a FREE SURFACE: No shear stress on a FREE SURFACEIf stresses were everywhere aligned with the earth’s surface…: If stresses were everywhere aligned with the earth’s surface…But if stresses are angled at depth…: But if stresses are angled at depth… Then they rotate to alignment near the surface!Andersonian Theory of Faulting:: Andersonian Theory of Faulting: The optimum shear fracture plane is always oriented at 60° to s1, 30° to s3, s2 is in the plane. Simple idea but VERY USEFUL - Provides link between faults and stresses - present and past.Rules of Thumb: Rules of Thumb “Thinning Direction” parallel to s1 “Thickening Direction” parallel to s3 Simple model - no motion along s2 SIMPLIFICATION! For now anyway. Remember the sandbox model from last week’s lab…s1 horizontal, s3 vertical: s1 horizontal, s3 verticals1 horizontal, s3 vertical: s1 horizontal, s3 verticals1 horizontal, s3 horizontal: s1 horizontal, s3 horizontals1 horizontal, s3 horizontal: s1 horizontal, s3 horizontals1 vertical, s3 horizontal: s1 vertical, s3 horizontals1 vertical, s3 horizontal: s1 vertical, s3 horizontalThe last of the CIRCULAR GRAPHS which will HAUNT YOU ALL QUARTER: The last of the CIRCULAR GRAPHS which will HAUNT YOU ALL QUARTER And Now, As Promised…Plane intersects sphere = Arc!: Plane intersects sphere = Arc!Convention: use the “Southern” Hemisphere of an imaginary sphere : Convention: use the “Southern” Hemisphere of an imaginary sphere Let’s start with a vertical plane cutting the hemisphere. It intersects on an ARC.: Let’s start with a vertical plane cutting the hemisphere. It intersects on an ARC.Now let’s look down from the North Star…: Now let’s look down from the North Star…Assign a coordinate system to get us oriented…: Assign a coordinate system to get us oriented…Reduce the clutter to a circle. : Reduce the clutter to a circle. Now let’s graph a plane onto it! Vertical plane - straight line through the pole Strike=45How about a horizontal plane?: How about a horizontal plane? Strike=?? It sits through the equator - all lines are horizontal so there’s no unique strike lineHow about plane 0/25W? : How about plane 0/25W? Strike=0 Or plane 0/55W? How about plane 45/25NW? : How about plane 45/25NW? Strike=45Template on which we can draw our circles: stereonet: Template on which we can draw our circles: stereonet You do not have the permission to view this presentation. In order to view it, please contact the author of the presentation.
01 13 05 Andersonian Heng Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINTLite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 270 Category: Entertainment License: All Rights Reserved Like it (0) Dislike it (0) Added: November 15, 2007 This Presentation is Public Favorites: 0 Presentation Description No description available. Comments Posting comment... Premium member Presentation Transcript The last of the CIRCULAR GRAPHS which will HAUNT YOU ALL QUARTER: The last of the CIRCULAR GRAPHS which will HAUNT YOU ALL QUARTER January 13, 2005 [Many thanks to H. Bob]Stress - Real Time: Stress - Real TimeSlide6: Map of global seismicityDefinitions: FRICTION: Definitions: FRICTION Same as sliding blocks from physics class (kinetic friction) Determines slope of Coulomb failure envelope For unconsolidated materials, m = angle of internal friction = angle of repose. For rocks, m = coefficient of friction of sliding surfacesDefinitions: COHESION: Definitions: COHESION For whole rocks: C = breaking strength. For broken surfaces: C = static friction. For unconsolidated sediment: C = ZERO. Like “static friction” from physics class No shear stress on a FREE SURFACE: No shear stress on a FREE SURFACEIf stresses were everywhere aligned with the earth’s surface…: If stresses were everywhere aligned with the earth’s surface…But if stresses are angled at depth…: But if stresses are angled at depth… Then they rotate to alignment near the surface!Andersonian Theory of Faulting:: Andersonian Theory of Faulting: The optimum shear fracture plane is always oriented at 60° to s1, 30° to s3, s2 is in the plane. Simple idea but VERY USEFUL - Provides link between faults and stresses - present and past.Rules of Thumb: Rules of Thumb “Thinning Direction” parallel to s1 “Thickening Direction” parallel to s3 Simple model - no motion along s2 SIMPLIFICATION! For now anyway. Remember the sandbox model from last week’s lab…s1 horizontal, s3 vertical: s1 horizontal, s3 verticals1 horizontal, s3 vertical: s1 horizontal, s3 verticals1 horizontal, s3 horizontal: s1 horizontal, s3 horizontals1 horizontal, s3 horizontal: s1 horizontal, s3 horizontals1 vertical, s3 horizontal: s1 vertical, s3 horizontals1 vertical, s3 horizontal: s1 vertical, s3 horizontalThe last of the CIRCULAR GRAPHS which will HAUNT YOU ALL QUARTER: The last of the CIRCULAR GRAPHS which will HAUNT YOU ALL QUARTER And Now, As Promised…Plane intersects sphere = Arc!: Plane intersects sphere = Arc!Convention: use the “Southern” Hemisphere of an imaginary sphere : Convention: use the “Southern” Hemisphere of an imaginary sphere Let’s start with a vertical plane cutting the hemisphere. It intersects on an ARC.: Let’s start with a vertical plane cutting the hemisphere. It intersects on an ARC.Now let’s look down from the North Star…: Now let’s look down from the North Star…Assign a coordinate system to get us oriented…: Assign a coordinate system to get us oriented…Reduce the clutter to a circle. : Reduce the clutter to a circle. Now let’s graph a plane onto it! Vertical plane - straight line through the pole Strike=45How about a horizontal plane?: How about a horizontal plane? Strike=?? It sits through the equator - all lines are horizontal so there’s no unique strike lineHow about plane 0/25W? : How about plane 0/25W? Strike=0 Or plane 0/55W? How about plane 45/25NW? : How about plane 45/25NW? Strike=45Template on which we can draw our circles: stereonet: Template on which we can draw our circles: stereonet