2Earth’s Interior Intro-duction We never have been able to visually see into the center of the Earth.The largest mine is in South Africa and is about 3.8 kilometers (2.4 miles) deep.
3Earth’s Interior Finding Indirect Evidence Scientists use indirect observation to observe the Earth’s interior.Scientists know about the interior of the Earth from waves produced by earthquakes.Seismic waves – waves produced by earthquakes.
4Earth’s Interior Finding Indirect Evidence The speed of the seismic waves tell scientists about the structure of the Earth.
6Earth’s Interior A Journey to the Center of the Earth To begin a journey to the center of the Earth, you would need to travel through solid rock.Temperatures and pressures would change as you travel towards the center.
7Earth’s Interior A Journey to the Center of the Earth Temperatures At first, the temperature around the surface is cool. Then temperatures increase rapidly for several miles and then increase slowly after that.For every 40 meters you travel inward, the temperature rises 1ºC (33.8ºF).A Journey to the Center of the Earth
8Earth’s Interior A Journey to the Center of the Earth Pressure The deeper you travel into the Earth, the greater the pressure.Pressure – the force pushing on a surface or area
9Earth’s Interior Chemical Layers of the Earth You will travel through several layers as you travel through the Earth.The Earth is made up of three main chemical layers.crustmantlecore
11Earth’s Interior Chemical Layers of the Earth Each layer has its own conditions and materials.Diagram From:eoearth.org
12Earth’s Interior The Crust Crust – a layer of rock that forms Earth’s outer skinVery thin layer of the Earth.Includes both the dry land and the ocean floor.Thickest under high mountains and thinnest under the ocean.
13Earth’s Interior The Crust Oceanic crust is made of dense materials. Continental crust is made of less dense materials.5-40 km thickMade of oxygen, silicon, aluminum, calcium, iron, sodium, potassium, and magnesium
20Earth’s Interior The Core The core makes up about 33% of the Earth’s mass but only 15% of the Earth’s volume.The core is VERY dense.Made of iron and nickelTemperatures range from 3630ºF – 5430ºF (2,000ºC – 3,000ºC)
25Earth’s Interior Astheno-sphere Material in the mantel is softer and can bend, somewhat like plastic.
26Earth’s Interior Astheno-sphere Asthenosphere – the soft rock layer of the Earth that can flow slowlyThe lithosphere floats on top of the asthenosphere.Enormous heat and pressure allow this soft, solid rock to move.
27Earth’s Interior The Crust Lithosphere Crust (rigid) Asthenosphere (plastic)MantleCore
28Earth’s Interior Meso-sphere Mesosphere– the hard rock layer that makes up most of the mantleExtreme pressure at this depth makes the rock very hard and unable to move like the asthenosphere.
29Earth’s Interior The Crust Lithosphere Crust (rigid) Asthenosphere (plastic)MantleMesosphere(rigid)Core
30Earth’s InteriorCoreThe core has two parts, an outer core and inner core.Outer core – a layer of molten, liquid metal that surrounds the inner coreInner core – a dense ball of solid metal
32Earth’s Interior Physical Layers of the Earth Diagram From: geophysics.ou.edu
33Earth’s Interior Physical Layers of the Earth Diagram From: faculty.weber.edu
34Earth’s InteriorPhysical Layers of the EarthDiagram From:spring.net
35Earth’s Interior Physical Layers of the Earth Layers of the Earth Depiction
36Earth’s Interior Earth’s Magnetic Field Currents in the liquid outer core force the solid inner core to spin at a slightly faster rate than the rest of the planet.The currents created by the outer core create the Earth’s magnetic field.
37Earth’s Interior Earth’s Magnetic Field The Earth acts like a giant bar magnet.A compass will point to the Earth’s magnetic North pole.
38Earth’s Interior Earth’s Magnetic Field Diagram From: glossary.oilfield.slb.com