Volcanoes and Earhtquakes

1. Measuring earthquakes and volcanoes

There are many ways to measure and earthquake. Magnitude is the most common way to measure an earthquake’s size. It is a measure of the size of the earthquake source and is the same number no matter where you are or what the shaking felt like. The Richter scale measures the largest shake on the recording, but there are other magnitude scales that measure different parts of the earthquake. Another way to measure an earthquake is to measure the intensity, or the shaking or damage done. This value changes depending on the epicenter or focus; the closer to the fault of the earthquake, the more damage done, and visa versa.1



Measuring Earthquakes; http://teamforce.wikispaces.com/CSTC+2.2

The area around a volcano swells, deflates or shifts as the lava or magma moves around inside of it. There are scientists that can watch the movement of these volcanoes and determine if they are going to blow. They use spirit level surveys to measure elevation changes. A spirit level is a telescope with its optical axis aligned to horizontal with a level vial.2

Erupting Volcano; http://denialdepot.blogspot.com/2009/04/co2-levels-may-have-been-over-2000ppm.html

2. Chemical Composition of Magma

Magma is a mixture of liquid rock, crystals, and dissolved gas. The human eyes have seen the only part on earth that is liquid which is the outer core. But the core is not likely to be the source of magma because it doesn’t have the right chemical composition. The outer core, or crust, is mainly Iron, but magma is a silicate liquid. Thus, Magma doesn’t come from the Earth’s crust. Since the rest of the Earth’s crust is sold, some part of the earth, below the surface, must get hot enough to melt the rocks to form magma.3

How does magma move the tectonic plates?

            The earth is like a giant puzzle with the tectonic plates as the pieces. Every year, the tectonic plates move a centimeter or two. The ocean floors are constantly moving and spreading. As these tectonic plates move, the earth’s crust is moving and magma deep in the earth’s core is being pushed upward causing the earth’s crust to bend upward, creating mountains and volcanoes. These plates spread farther to make room for this pressure the magma lays on the earth’s outer core. When the magma is under a great amount of pressure, the volcano will erupt sending tons of ash, lava, and rocks into the air and plummeting down onto earth’s surface.4

Volcano creation; http://www.pacificislandtravel.com/nature_gallery/volcanoes.html

C.) The Atmosphere, Hydrosphere, and other Earth Systems

The Atmosphere:

Volcanoes affect the atmosphere by volcanic eruptions releasing lots of gases into the air, some of which pollute the environment and affect the atmospheric content. A main problem in Hawaii is that the volcanoes create a volcanic fog which lingers in the air long after a volcano erupts. Lava that spurts into the air also releases chemicals such as hydrogen sulfide, hydrogen chloride, and hydrogen fluoride. These gases can add to the greenhouse gases, contributing to global warming. These gases can also create acid rain.5

Hydrosphere:

In Hawaii, the volcanoes erupt quietly but lava will spill out into the ocean. This lava contains chemicals such as hydrogen sulfide. This sulfur can kill of marine life and contaminate the water. This contaminated water can be evaporated and dropped over human life in the form of acid rain.6

Lava running into the ocean; http://lovingthebigisland.wordpress.com/2009/01/15/volcano-watch-worlds-active-volcanoes-keep-scientists-busy-in-2008/

1.       http://earthquake.usgs.gov/learn/faq/?faqID=111

U.S. Department of the Interior; U.S. Geological Survey; EHP Web Team. (2009)

2.       http://hvo.wr.usgs.gov/volcanowatch/1994/

hvowebmaster@usgs.gov; Hawaiian Volcano Observatory. (1998)

3.       http://www.tulane.edu/~sanelson/geol204/volcan&magma.htm

Professor Stephen A. Nelson; Tulane University; Natural Disasters. (2011)

4.       http://www.moorlandschool.co.uk/earth/tectonic.htm

Moorland Private School; England. (2011)

5.       http://wiki.answers.com/Q/How_do_volcanoes_affect_the_earth's_atmosphere

Wikipedia Answers Corp. (2011)

6.       http://volcanoworld.wordpress.com/2009/03/24/how-do-volcanoes-affect-the-atmosphere-and-climate/

Volcano World: Supplement; Volcano Activity Reports and News; Worldpress.com. (2011)

The Water Cycle

 A.) The Water Cycle

The ware on Earth is always moving. The natural water cycle, also known as the hydrologic cycle, describes this movement of water on, above, and below Earth’s surface. Water can change between liquid, vapor, and ice. These processes have been happening in the blink of an eye for over millions of years.

Water Cycle; http://ga.water.usgs.gov/edu/watercycle.html

Why Evaporation/Condensation occurs:

Heat energy is need for evaporation to occur. Energy is used to break the bonds that hold water molecules together. Net evaporation occurs when the rate of evaporation exceeds the rate of condensation. Condensation occurs when saturated air is cooled below the dew point.

Precipitation and Transpiration:

Precipitation is water that is released from clouds in the sky. Precipitation can come in the form of rain, freezing rain, sleet, snow, or hail. It’s is the primary source in the water cycle that provides the delivery of water the Earth. Transpiration is the passage of water from a plants roots and leaves into the atmosphere. The more temperature rises, the higher chance transpiration will occur.

Infiltration and Groundwater/Aquifers:

Infiltration is the seepage of water into soil or rock.6  Some of the water that infiltrates will remain in the shallow soil layer, where it will move through the soil. Some water may infiltrate deeper, recharging groundwater aquifers. Aquifers are a good way to store groundwater, which is fresh, drinkable water. People can drill wells into these aquifers and use this water for whatever purpose they desire.

Surface runoff:

Surface runoff is the water flow that occurs when soil is infiltrated to full capacity and excess water from rain or other sources that flow over the land. When runoff flows along the ground, the water can pick up contaminants of the soil like pesticides or fertilizers. 1

B.) What is a Watershed?

A watershed is an area of land where all the water that is under it or drains off of it goes into the same place. In the words of John Wesley Powell, a scientist geographer, a Watershed is:

"that area of land, a bounded hydrologic system, within which all living things are inextricably linked by their common water course and where, as humans settled, simple logic demanded that they become part of a community." 2

Watershed; http://water.epa.gov/type/watersheds/whatis.cfm

Watersheds are also known as ‘drainage basins’. A drainage basin is an area of land where surface water from rain and melting snow or ice comes to a single point, usually the exit of the basin, where the waters join another water body,

such as a river, lake, reservoir, estuary, wetland, sea, or ocean. 3

C.) Rivers

There are 3 types of rivers: Whitewater, black water, and Clearwater. A Whitewater river is a river where

there are rapids or water turbulence present. There is a classification system from Whitewater Rivers based

on difficulty and danger; they are rated on a scale from I-VI. (1-7) Class I is usually water that is very still

and calm and has few obstructions, while class VI has no visibility (when rafting), very dangerous waters,

and many obstructions. (When rafting, this class of Whitewater River can cause death)

A Black water river is a deep, slow-moving river that runs through swamps and wetlands. White water and

black water differs mainly in ionic compounds. Black waters are more acidic due to vegetation decay.

They also differ in sodium, magnesium, and calcium levels. 5

Clearwater Rivers are named for their clear, clean waters. Because of their elevation, they tend to run

over rocks. Because of the clarity of the water, these rivers tend to have plant growth such as algae in them. 4

All these rivers move and were created by the movement of the Earth’s runoff. Most rivers run

downhill or towards another larger river or an ocean. The flow of the river is determined by the Earth’s

crust and the plant growth, animals and other things around it.

Blackwater River; http://en.wikipedia.org/wiki/File:Blackwater_River_Blackwater_Falls_State_Park_West_Virginia.jpg

 Bibliography:

1.       http://ga.water.usgs.gov/edu/watercycle.html

Howard Perlman; U.S. Geological survey; U.S. Department of the Interior. (2011)

2.       http://water.epa.gov/type/watersheds/whatis.cfm

U.S. Environmental Protection Agency Office of Water. (2011)

3.       http://www.dcr.virginia.gov/stormwater_management/hu.shtml

Hydrologic Unit Geography; Virginia Department of Conservation & Recreation. (2010)

4.       http://rainforests.mongabay.com/0602.htm

Rhett Butler; Mongabay.com. (2009)

5.       http://www.amazonian-fish.co.uk/indexc30.html

Comparison between Black and White waters; Amazonian Fishes and their Habitats. (2006)