Chapter 2

The Earth’s History (section 1)

  • God’s work in the earth’s history can be divided into four phases: the Creation, the Flood, the modern world, and the future world.
  • Uniformitarianism—the belief that the universe has existed unchanged for an immeasurable amount of time and will continue to exist forever; the principle that the same scientific laws and processes are constant throughout space and time.
  • People who hold to the belief of uniformitarianism support the theory of evolution.
  • Christians believe the earth’s features were changed by a cataclysm (the New Testament word for the Flood).
  • The Flood waters softened the earth’s surface greatly because of this the earth was easily shaped.

The Earth Today (section 2)

  • God has divided the earth into three parts:
  • The atmosphere—the covering of air that surrounds our plant
  • The lithosphere—the solid part of the earth
  • The hydrosphere—the water on the earth’s surface
  • The outer skin of the earth’s surface is called the crust.
  • Sima—The bottom layer of basaltic rock
  • Sial—slabs of granitic rock
  • Mantle—the hot middle layer of the lithosphere
  • Core—the center of the earth made of iron and nickel
  • Islands—landmasses surrounded by water
  • There are six continental landmasses, but seven continents.
  • Eurasia is often considered two continents.
  • If the oceans were a little lower, the largest islands of the world would all become part of the nearby continents. We call these areas continental islands.
  • There are four principal bodies of water in the world: the Pacific, the Atlantic, the Indian, and the Arctic Oceans.
  • The whole system is sometimes called the world ocean.

Major Landforms (section 3)

  • Landform—slight variation in the landscape
  • Plains—wide areas of level land
  • Plains are the most valuable landform for farmers.
  • Rivers bring water and sediments down from the mountains, and deposits, called alluvium, settle in the flat plains.
  • Plateaus are wide areas of relatively flat land, like plains, but they rise abruptly above surrounding lands.

At the Water’s Edge (section 4)

  • Tributaries—rivers that “feed” other rivers
  • River System—the main river and all its tributaries
  • There are several ways to compare rivers
  • Length—how long it flows
  • Discharge—their flow of water
  • Drainage Area—the total land area drained by it
  • Navigability—their depths
  • The Nile is the longest river.
  • Navigability—the most important factor for trade
  • Barges rely on deep, navigable rivers for carrying food, coal, lumber, and other goods from their distant sources to coastal cities.
  • The Caspian Sea is the world’s largest lake
  • At the Water’s Edge (continued)
  • Areas of stagnant water, often referred to as bogs, swamps, moors, fens, muskegs, or marshes, are collectively known as wetlands.
  • Bogs describe spongy areas that look dry but are covered with wet organic materials.
  • A marsh has visible standing water.The main kinds of vegetation are grasses and small water plants.
  • Swamps are covered by standing water and dominated by large trees.

Forces that Change the Earth’s Surface (section 5)

  • According to the plate tectonics theory, the plates crash into one another and pull apart, releasing energy from the earth’s interior and causing earthquakes and volcanoes.
  • Folding—a bend in the earth’s crust
  • Volcanoes deposit new lava on the earth’s surface, which hardens into depositional mountains.
  • Weathering is the breakdown of rocks by temperature changes, water, plant roots, and the formation of ice and mineral crystals.
  • Weathering produces particles of sand, silt, and clay (called sediment) that mix with humus (decayed substances produced by living organisms) to form soil. Farmers carefully study their soils to find out what fertilizers will make the land most productive.
  • Erosion—the natural removal of material
  • Many forces cause erosion, such as wind, waves, glaciers, and running water.
Bookmark and Share

Comments are closed.