Chapter 21 - Crater Types

There are three types of craters that can be distinguished on the Earth’s surface; simple craters, complex craters, and complex craters with a distinct uplift, peak, or ring. Simple craters have have diameters up to 4 km, with uplifted or overturned rim socks surrounding a smooth bowl-shaped depression partially filled by impact breccias. Complex craters are generally over 4 km in diameter and exhibit slumped terraced rims. Complex craters with a central uplift, peak or ring share the same characteristics as complex craters except they exhibit a distinct central uplift and an annular (ring shaped) trough.

Chapter 25 - Active, Dormant, and Extinct Volcanoes

An active volcano is one that has erupted in recorded history, and was observed erupting. A dormant volcano has not been seen to erupt, but it shows evidence of recent activity. When a volcano shows no signs of life and exhibits evidence of long-term weathering and erosion, it is tentatively identified as an extinct volcano. This title is tenuous, as it is not speaking to an absolute dormancy, rather an observed dormancy, leaving room for the volcano to come to life again with little warning. A great number of active continental volcanoes lie in or near spreading and subduction zones. Many of the world’s most famous mountains are volcanic peaks standing astride or near plate margins: mount fiji, Mount Versuvius, Mount St Helen's and Mount Rainier.

Chapter 25 - Composit Volcanoes

Many of the great volcanoes that formed over subductive margins are composite volcanoes which disgorge mainly pyroclastic materials including ash as well as gases. These edifices are the classic ‘volcano’ shape, and in a cross-section such volcanoes look layered. Composite volcanoes, with their acidic, gas-filled lavas, are also notoriously dangerous. They often erupt explosively with little or no warning. Pyroclastics can be hurled far from the crater and volcanic ash can go into the stratosphere and affect the climate of a part of the while of the world. Ash can create health hazards that choke human and animal life away from the volcano. 

Chapter 26 - Earthquake Terminology

Lithospheric plates collide at collision margins, producing fractures in rocks called faults. A fault is a fracture in crustal rock involving the displacement of rock on one side of the fracture with respect to rock on the other side. Like volcanoes, certain faults are active where as others are no longer subject to stress. When rock strata are subjected to stress, they begin to deform or bend. All rocks have a certain rupture strength, which means that they will continue to bend, rather then break, as long as the stress imposed on them does not exceed this rupture strength. When the stress finally becomes too great, the rocks fracture suddenly and move along a plane (the fault) that may or may not have existed before the deformation began. That sudden movement snaps the rocks on each side of the fault back into their original shape and produces an earthquake.

Chapter 26 - Earthquake

An earthquake is the release of energy that has slowly built up during the stress of increasing deformation of rocks. These energy releases take the form of seismic waves that radiate in all directions from the place of movement. Earthquakes can originate at or near the surface of the Earth, deep inside the crust, or even in the upper mantle. The place of origin is the focus (or the center), and the point directly above the focus on the surface is known as the epicenter. Earthquakes range from tremors so small that they are hardly noticeable, to great city destroying shocks This reflects their magnitude, the amount of shaking of the ground as the quake passes as measured by a seismograph.

Chapter 23 - Sedimentary Rocks

Sedimentary rocks are a result of the erosion, transportation, deposition, and compaction (lithification) of rock fragments and minerals derived from other rocks. These grains are weathered and broken away from existing rocks by the action of water, wind and ice. The deposited rock fragments and grains are squeezed tightly together and compacted, finally these fragments are cemented together by thin layers of mineral matter such as silica and calcite. Sandstone, an example of a sedimentary rock, is formed of sand-sized grains that are often quartz grains. Some sandstone is very hard and resistant to erosion, other sandstone is very brittle and can come apart in your hand. This video illustrates very brittle sandstone found in the badlands of Drumheller. This sandstone is so soft that it literally comes apart when rubbed with ones foot. It is clear by the shape of the sandstone that it is not very resistant to erosion, obvious from the wavy like shape it exhibits.

Chapter 9 - Causes of Atmosphere Pressure

Two basic factors explain the circulation of air in the atmosphere: 1) The Earth receives an unequal amount of heat energy at different latitudes, and 2) it rotate son its axis. The area between the equator and the 35th parallel receives a surplus of net radiation, while the latitudes poleward of the 35th parallel has a deficiency of radiation, with the outgoing amount surpassing that of the incoming amount. The main for this unequal distribution of heat energy is because the sun hits the earth at higher angles, and thus the lower latitudes receive a greater intensity. As a result the equator receives about 2.5 times as much solar radiation as the poles.