Chapter 9: Plate Tectonics
continental drift Wegener's hypothesis that all continents were once connected in a single large landmass that broke apart and drifted slowly to their current positions.
Pangaea the large "supercontinent” that is believed to have connected all of the continents on earth about 225 million years ago
Evidence for Continental Drift Hypothesis The continental puzzle – continents fit together like a puzzle Matching fossils – fossil evidence for continental drift includes several fossil organisms found on different continents. Rock type and structures – rock evidence for continental drift exists in the form of several mountain belts that end at one coastline, only to reappear on a landmass across the ocean. Ancient climates – ancient climate evidence supported continental drift
plate tectonics the theory that the earth's outer shell is composed of a number of large plates, or slabs of rock, whose constant movement explains earthquakes and volcanic activity.
Plate tectonics : chapter 9.3 & 9.4
tectonic plate a large section of Earth's lithosphere that moves around on the asthenosphere.
Convection currents Convection currents occur when a gas or a liquid is heated from the bottom. Warm gasses & liquids are less dense than cold. The warm substance rises and the cold sinks. This process is responsible for air, ocean, & mantel currents. Pair share: what lab did we do that demonstrated convection currents?
Convection currents Convection currents occur when a gas or a liquid is heated from the bottom. Warm gasses & liquids are less dense than cold. The warm substance rises and the cold sinks. This process is responsible for air, ocean, & mantel currents. Pair share: what lab did we do that demonstrated convection currents?
Convection currents Convection currents occur when a gas or a liquid is heated from the bottom. Warm gasses & liquids are less dense than cold. The warm substance rises and the cold sinks. This process is responsible for air, ocean, & mantel currents. Pair share: what lab did we do that demonstrated convection currents?
Types of Plate Boundaries The three main types of boundaries are convergent, divergent, and transform fault boundaries.
Divergent Boundaries in divergent boundaries plates move apart Most divergent boundaries are located along the crests of oceanic ridges.
seafloor spreading The process by which plate tectonics produces new oceanic lithosphere at ocean ridges
Convergent Boundaries Convergent Boundaries – two tectonic plates move TOGETHER
Convergent Boundaries Oceanic – Continental When a continental plate converges with an oceanic plate, the more dense oceanic plates subducts under the continental plate Continental volcanic arc / volcanic activity is caused by the subduction of the oceanic crust melting below when it sinks into the asthenosphere.
Convergent Boundaries Oceanic – Continental plate boundary
Convergent Boundaries Continental- Continental the collision of the two continental plates form complex mountains. ex: Himalayan Mountains
Convergent Boundaries: Continental-Continental
subduction zone A destructive plate margin where oceanic crust is being pushed down into the mantle beneath a second plate
subduction zone A destructive plate margin where oceanic crust is being pushed down into the mantle beneath a second plate
trench A surface feature in the seafloor produced by the descending plate during subduction
Transform Boundaries At a transform plate boundary, plates grind past each other without destroying the lithosphere. Ex: San Andreas Fault
Transform Boundaries At a transform plate boundary, plates grind past each other without destroying the lithosphere. Ex: San Andreas Fault
Earth Science – Chapter 9.2 9.2 Plate tectonics
Earth Science – Chapter 9.2 9.2 Plate tectonics
Earth’s Major Plates
Types of Plate Boundaries Quiz
Types of Plate Boundaries Quiz
volcanic island arc A chain of volcanic islands generally located a few hundred miles from a trench where subduction of one oceanic slab beneath another is occurring