Survey of Astronomy Astro1010-lee.com Chapter 6 Our Living Earth

Survey of Astronomy Astro1010-lee.com Chapter 6

Astro1010-lee.com UVU Survey of Astronomy Solar System Formation Cloud of gas and dust contracts due to gravity. Conservation of Angular Momentum means it spins faster and faster as it contracts

Survey of Astronomy Astro1010-lee.com Chapter 6 Our Solar System Condensation theory : Interstellar dust grains help cool the cloud, and act as condensation nuclei to produce flakes, grains, lumps, planetesmals then planets

Foucault Pendulum Survey of Astronomy Astro1010-lee.com Chapter 6

Coriolis Force Survey of Astronomy Astro1010-lee.com Chapter 6

The interior of the Earth has been determined by studying the transmittal and reflection of Seismic Waves within the Earth. Survey of Astronomy Astro1010-lee.com Chapter 6

Seismic waves are sound waves generated by earthquakes. They are compression waves and sinesoidal waves. They reflect from and transmit through layer interfaces with the Earth. Survey of Astronomy Astro1010-lee.com Chapter 6

Can use the pattern of reflections made during earthquakes to deduce interior structure of Earth Survey of Astronomy Astro1010-lee.com Chapter 6

Results from Seismometers Survey of Astronomy Astro1010-lee.com Chapter 6

Tectonic Plates Survey of Astronomy Astro1010-lee.com Chapter 6

The crust of the Earth is divided into several plates that move with respect to each other. The movement is driven by convection currents in the mantle. Plate movement results in earthquakes and volcanism. Survey of Astronomy Astro1010-lee.com Chapter 6

Interactions between the plates are: transform, sliding against each other; divergence, separating; convergence, coming together. Survey of Astronomy Astro1010-lee.com Chapter 6

Ocean Floor Spreading shows evidence of Magnetic Field Reversal Survey of Astronomy Astro1010-lee.com Chapter 6

When plates slide against each other cracks (faults) occur and earthquakes happen. Survey of Astronomy Astro1010-lee.com Chapter 6

The twisting Pacific plate has produced many earthquake zones and many active volcanoes. Survey of Astronomy Astro1010-lee.com Chapter 6

At divergent boundaries new crust is made. Survey of Astronomy Astro1010-lee.com Chapter 6

At convergent boundaries crust is lost by subduction (sliding under) and crumpling (mountain building) Survey of Astronomy Astro1010-lee.com Chapter 6

The Earth’s magnetic field appears to be generated by electric currents circulating the liquid iron core. Survey of Astronomy Astro1010-lee.com Chapter 6

The Magnetic Field deflects the Solar Wind around the Earth much like a stone in a stream deflects water. Charged particles that penetrate the boundary are trapped in the Van Allen Belts Survey of Astronomy Astro1010-lee.com Chapter 6

The trapped hot charged particles in the Van Allan belts are shunted toward the magnetic poles where they interact with the air molecules. The particles are cooled by the air which glows as auroras. Survey of Astronomy Astro1010-lee.com Chapter 6

The Earth’s Biosphere, Oceans and Atmosphere, come from hydrogen rich gasses trapped inside the Earth during creation. By far the most abundant of the trapped gasses are methane, ammonia, and water. The Earth is the only planet where conditions are right for liquid water to exist on the surface. Survey of Astronomy Astro1010-lee.com Chapter 6

Free H CH 4 NH 3 OH 2 CO 2 N2N2 Water Plant Life O2O2 Trapped gasses Outgassing Water Nitrogen Carbon Dioxide Plant Life Oxygen Survey of Astronomy Astro1010-lee.com Chapter 6 Earth’s Atmosphere

Troposphere is where convection takes place – responsible for weather The blue curve shows the temperature at each altitude Survey of Astronomy Astro1010-lee.com Chapter 6 The Atmosphere

Convection depends on warming of ground by the Sun Survey of Astronomy Astro1010-lee.com Chapter 6

Ionosphere is ionized by solar radiation, and is good conductor Reflects radio waves in the AM range, but is transparent to FM and TV Ozone layer is between ionosphere and mesosphere; absorbs ultraviolet radiation Survey of Astronomy Astro1010-lee.com Chapter 6

The Human Element More Humans, Industrial Revolution Global Warming (?) Survey of Astronomy Astro1010-lee.com Chapter 6

Survey of Astronomy Astro1010-lee.com Chapter 6 End Chapter 6