Lesson 19: Other Geological Hazards (Landslides and Sinkholes) PDF

LETS HAVE A QUICK REVIEW  LETS HAVE A QUICK REVIEW  LETS HAVE A QUICK REVIEW  LETS HAVE A QUICK REVIEW  LETS HAVE A QUICK REVIEW  WHAT DO YOU THINK OUR TOPIC FOR TO DAY CLASS? OTHER GEOLOGICAL HAZARDS (LANDSLIDE AND SINKHOLE) WHAT IS A LANDSLIDE CLASS?  WHAT IS A LANDSLIDE CLASS?...

LETS HAVE A QUICK REVIEW  LETS HAVE A QUICK REVIEW  LETS HAVE A QUICK REVIEW  LETS HAVE A QUICK REVIEW  LETS HAVE A QUICK REVIEW  WHAT DO YOU THINK OUR TOPIC FOR TO DAY CLASS? OTHER GEOLOGICAL HAZARDS (LANDSLIDE AND SINKHOLE) WHAT IS A LANDSLIDE CLASS?  WHAT IS A LANDSLIDE CLASS? A landslide is defined as the movement of a mass of rock debris, or earth down a slope. Landslides are a type of "mass wasting", which denotes any down-slope movement of soil and rock under the direct influence of gravity WHAT IS A LANDSLIDE CLASS? Landslides occur when gravitational and other types of shear stresses within a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. WHAT IS A SINKHOLES CLASS? Landslides occur when gravitational and other types of shear stresses within Landslides occur when gravitational and other types of shear stresses within a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. WHAT IS A SINKHOLES CLASS? Sinkholes are common where the rock below the land surface is limestone, Landslides occur when gravitational and other types of shear stresses within carbonate rock, salt beds, or Landslides occur when gravitational and other types of shear stresses within a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. rocks that can naturally be dissolved by groundwater circulating through them  WHAT IS A SINKHOLES CLASS? As the rock dissolves, spaces and caverns develop underground. Sinkholes are dramatic because the Landslides occur when gravitational and other types of shear stresses within Landslides occur when gravitational and other types of shear stresses within a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. land usually stays intact for a while a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. until the underground spaces just get too big TYPES OF LANDSLIDES  TYPES OF LANDSLIDES Slides Falls Topples Flowss Lateral Spreads  TYPES OF LANDSLIDES The Slides Although many types of mass movements are included in the general term "landslide," the more restrictive use of the term refers only to Landslides occur when gravitational and other types of shear stresses within Landslides occur when gravitational and other types of shear stresses within a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. mass movements, where there is a distinct zone of weakness that separates the slide material from more stable underlying material  TYPES OF LANDSLIDES Two major types of slides Rotational slides Landslides occur when gravitational and other types of shear stresses within Landslides occur when gravitational and other types of shear stresses within a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. Translational slides - Block slide  TYPES OF LANDSLIDES Rotational slide This is a slide in which the surface of rupture is curved concavely upward and the slide movement is roughly Landslides occur when gravitational and other types of shear stresses within Landslides occur when gravitational and other types of shear stresses within a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. rotation about an axis that is parallel to the ground surface and transverse across the slide TYPES OF LANDSLIDES Landslides occur when gravitational and other types of shear stresses within Landslides occur when gravitational and other types of shear stresses within a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. a slope exceed the shear strength (resistance to shearing) of the materials that form the slope.  TYPES OF LANDSLIDES Translational slide: In this type of slide, the landslide mass moves along a roughly planar surface with little rotation or backward tilting. Landslides occur when gravitational and other types of shear stresses within Landslides occur when gravitational and other types of shear stresses within a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. - A block slide is a translational slide in which the moving mass consists of single unit or a few closely related units that move downslope TYPES OF LANDSLIDES Landslides occur when gravitational and other types of shear stresses within Landslides occur when gravitational and other types of shear stresses within a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. a slope exceed the shear strength (resistance to shearing) of the materials that form the slope.  TYPES OF LANDSLIDES Falls - are abrupt movements of masses of geologic materials, such as rocks and Landslides occur when gravitational and other types of shear stresses within Landslides occur when gravitational and other types of shear stresses within a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. boulders, that become detached from steep slopes or cliffs TYPES OF LANDSLIDES Landslides occur when gravitational and other types of shear stresses within Landslides occur when gravitational and other types of shear stresses within a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. a slope exceed the shear strength (resistance to shearing) of the materials that form the slope.  TYPES OF LANDSLIDES Topples - Toppling failures occur when large blocks of material rotate forward Landslides occur when gravitational and other types of shear stresses within Landslides occur when gravitational and other types of shear stresses within a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. and outward, often around a pivot point located below the center of gravity of the mass. TYPES OF LANDSLIDES Landslides occur when gravitational and other types of shear stresses within Landslides occur when gravitational and other types of shear stresses within a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. a slope exceed the shear strength (resistance to shearing) of the materials that form the slope.  TYPES OF LANDSLIDES FLOWS: There are five basic categories of flows that differ Landslides occur when gravitational and other types of shear stresses within Landslides occur when gravitational and other types of shear stresses within a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. from one another in fundamental ways.  TYPES OF LANDSLIDES FLOWS: Debris flow Debris avalanche Landslides occur when gravitational and other types of shear stresses within Landslides occur when gravitational and other types of shear stresses within a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. Earthflow Mudflow Creep  TYPES OF LANDSLIDES Debris flow - A debris flow is a form of rapid mass movement in which a Landslides occur when gravitational and other types of shear stresses within Landslides occur when gravitational and other types of shear stresses within a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. combination of loose soil, rock, a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. organic matter, air, and water mobilize as a slurry that flows downslope TYPES OF LANDSLIDES Landslides occur when gravitational and other types of shear stresses within Landslides occur when gravitational and other types of shear stresses within a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. a slope exceed the shear strength (resistance to shearing) of the materials that form the slope.  TYPES OF LANDSLIDES Debris avalanche This is a variety of very rapid to extremely rapid debris Landslides occur when gravitational and other types of shear stresses within Landslides occur when gravitational and other types of shear stresses within a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. flow TYPES OF LANDSLIDES Landslides occur when gravitational and other types of shear stresses within Landslides occur when gravitational and other types of shear stresses within a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. a slope exceed the shear strength (resistance to shearing) of the materials that form the slope.  TYPES OF LANDSLIDES Earthflow - Earthflows have a characteristic "hourglass" Landslides occur when gravitational and other types of shear stresses within Landslides occur when gravitational and other types of shear stresses within a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. shape. The slope material liquefies and runs out, forming a bowl or depression at the head. TYPES OF LANDSLIDES Landslides occur when gravitational and other types of shear stresses within Landslides occur when gravitational and other types of shear stresses within a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. a slope exceed the shear strength (resistance to shearing) of the materials that form the slope.  TYPES OF LANDSLIDES Mudflow - A mudflow is an earthflow consisting of material that is wet Landslides occur when gravitational and other types of shear stresses within Landslides occur when gravitational and other types of shear stresses within a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. enough to flow rapidly and a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. that contains at least 50 percent sand-, silt-, and clay-sized particles.  TYPES OF LANDSLIDES Creep - Creep is the imperceptibly slow, steady, downward movement of Landslides occur when gravitational and other types of shear stresses within Landslides occur when gravitational and other types of shear stresses within a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. slope-forming soil or rock. Movement is caused by shear stress sufficient to produce permanent deformation TYPES OF LANDSLIDES Landslides occur when gravitational and other types of shear stresses within Landslides occur when gravitational and other types of shear stresses within a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. a slope exceed the shear strength (resistance to shearing) of the materials that form the slope.  TYPES OF LANDSLIDES Lateral spreads - are distinctive because they usually occur on very gentle slopes Landslides occur when gravitational and other types of shear stresses within Landslides occur when gravitational and other types of shear stresses within a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. or flat terrain TYPES OF LANDSLIDES Landslides occur when gravitational and other types of shear stresses within Landslides occur when gravitational and other types of shear stresses within a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. WHAT ARE THE 5 TYPES OF LANDSLIDES? Landslides occur when gravitational and other types of shear stresses within Landslides occur when gravitational and other types of shear stresses within a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. a slope exceed the shear strength (resistance to shearing) of the materials that form the slope.  TYPES OF LANDSLIDES Slides Falls Topples Flowss Lateral Spreads TYPES OF SINKHOLES Landslides occur when gravitational and other types of shear stresses within Landslides occur when gravitational and other types of shear stresses within a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. a slope exceed the shear strength (resistance to shearing) of the materials that form the slope.  TYPES OF SINKHOLES Cover-collapse sinkholes Cover-subsidence sinkholes Landslides occur when gravitational and other types of shear stresses within Dissolution sinkholes Landslides occur when gravitational and other types of shear stresses within a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. a slope exceed the shear strength (resistance to shearing) of the materials that form the slope.  TYPES OF SINKHOLES Cover-collapse sinkholes - may develop abruptly (over a period of hours) and thus cause catastrophic Landslides occur when gravitational and other types of shear stresses within Landslides occur when gravitational and other types of shear stresses within a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. damages. They occur when there is a a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. thick layer of cover material (clay, sand, or other sediment) overlying a void in the bedrock TYPES OF SINKHOLES Landslides occur when gravitational and other types of shear stresses within Landslides occur when gravitational and other types of shear stresses within a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. TYPES OF SINKHOLES Landslides occur when gravitational and other types of shear stresses within Landslides occur when gravitational and other types of shear stresses within a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. a slope exceed the shear strength (resistance to shearing) of the materials that form the slope.  TYPES OF SINKHOLES Cover-subsidence sinkholes - tend to develop gradually where the covering sediments are Landslides occur when gravitational and other types of shear stresses within Landslides occur when gravitational and other types of shear stresses within a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. permeable and contain sand. They are smaller and thus may go undetected for long periods. TYPES OF SINKHOLES Landslides occur when gravitational and other types of shear stresses within Landslides occur when gravitational and other types of shear stresses within a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. TYPES OF SINKHOLES Landslides occur when gravitational and other types of shear stresses within Landslides occur when gravitational and other types of shear stresses within a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. a slope exceed the shear strength (resistance to shearing) of the materials that form the slope.  TYPES OF SINKHOLES Dissolution sinkholes - These sinkholes form when rainwater (which is slightly acidic) dissolves the Landslides occur when gravitational and other types of shear stresses within Landslides occur when gravitational and other types of shear stresses within a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. soluble bedrock (typically limestone, gypsum, or salt) near the surface. The rock is slowly eroded away by the water, creating a depression TYPES OF SINKHOLES Landslides occur when gravitational and other types of shear stresses within Landslides occur when gravitational and other types of shear stresses within a slope exceed the shear strength (resistance to shearing) of the materials that form the slope. a slope exceed the shear strength (resistance to shearing) of the materials that form the slope.