Fri. April 25 Do Now Describe the three types of volcanoes. What does it mean if something is described as a composite (like a composite volcano)?

The Surface of Earth Earth’s surface is constantly changing. Recall that earthquakes, volcanoes, mountains, and the construction of new lithosphere are events that occur at plate boundaries. These events are changing the Earth’s surface all the time.

The Surface of Earth The features we see on Earth’s surface represent the balance between constructive processes versus destructive processes.

Mountain Building Mountain-building is a major constructive process. Mountains form in three main ways: by folding at convergent plate boundaries by movement of chunks of land at faults by volcanic activity

Erosion Erosion (also known as weathering) is a major destructive process. Erosion describes the continuous physical and chemical events that cause land & rock to wear down.

Erosion The rate of erosion is related to the height and steepness of the mountain—the steeper the mountain is, the faster it erodes because it is easier to push material down a steep slope than a gradual slope.

Soil: Why should you Care?! Soil is formed as a result of erosion. Soil is made of weathered rock and decayed plants and animals. Soil is rich in nutrients (substances that provide energy or building material for the survival and growth of a living things). It provides a good place for plants to anchor their roots and grow. Through plants, the nutrients are passed on to us!

Young soil does not have each of these layers. Soil Profiles A soil profile is a cross-section that shows the different layers of soil in the ground. It takes a long time & a lot of weathering for soil to have all the layers. Young soil does not have each of these layers.

A glacier is a huge mass of ice that can be many kilometers thick and thousands of kilometers wide. Glaciers at the poles are a frozen form of about 2 percent of all the water on Earth. Glaciers are formed from the accumulation of snow over hundreds or thousands of years. Glaciers

Geologic Hazard Maps Geologic hazard maps indicate the location of faults where earthquakes occur, areas where volcanoes are active, and where landslides, avalanches, floods, or other natural hazards are possible.

Urban Sprawl The term urban sprawl refers to how living areas around a city “sprawl” as they grow instead of concentrate near facilities that serve the people of the community.

Urban Sprawl Building roads changes the land. Roads and parking lots prevent water from slowly seeping into the ground to replenish the water supply in aquifers.

Volcanic activity results in formation of two kinds of igneous rocks: extrusive intrusive A batholith is a large underground rock formed when a mass of magma cools underground.

29.3 Rocks and Minerals A mineral is a solid, naturally-occurring object with a defined chemical composition. Minerals are inorganic and have a crystalline structure. Minerals are the building blocks of a rock. Granite- a type of rock

29.3 Rocks and Minerals Graphite and diamonds are two different minerals that are made of pure carbon.

29.3 Rocks and Minerals A mineral is a material that is naturally occurring, inorganic, and crystalline. There are more than 3,000 minerals on Earth. About 20 minerals make up Earth’s crust.

29.3 Identifying Minerals Mohs hardness scale was developed in 1812 by Friedrick Mohs (an Austrian mineral expert) as a method to identify minerals. Most minerals (except metals) have one or more cleavage planes that also help in determining their identity.

29.3 Identifying Rocks A rock is a naturally formed solid usually made of one or more minerals. The terms igneous, sedimentary, and metamorphic refer to how a rock was formed. The rock cycle illustrates the formation and recycling of rocks by geological processes.

29.3 Identifying Rocks Observe and ask questions: What does the rock look like? Examine the grain of a section. What is the rock's composition? Determine what minerals are in it. Where was the rock found? Mountain Stream or river Volcano Ocean floor

29.3 Rocks and Minerals Key Question: How can we interpret the stories within rocks? *Read text section 29.3 BEFORE Investigation 29.3