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The Dynamic Earth and Space GeodesyEATS 1010 3.0 [Fall 2011]

Instructor: Gary Jarvis, Department of Earth and Space

Science & Engineering (ESSE)

117 Petrie Science & Engineering Building

jarvis@yorku.ca, 416-736-2100 Ext. 77710

Laboratory Coordinator: Terry Du, 77706 terrydu@yorku.ca

Text: The Dynamic Earth and Space Geodesy, SC/EATS 1010 3.0 (Custom Publication for York University)

ESSE office: 102 Petrie Science & Engineering,

416-736-2100 Ext. 55245

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Topics•Origin of the Earth Large Scale•Impact Craters•Earth’s Interior•Plate Tectonics•Geomagnetism•Seismology•Space Geodesy & Geomatics•VLBI•GPS•GIS•Remote Sensing Small Scale

The Dynamic Earth and Space GeodesyEATS 1010 3.0 [Fall 2011]

What is it?

How do we m

easure it?

Earth as a Planetary Body in Space

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Course Marking Scheme & Schedule

5 Laboratory Exercises: 20% Sept. 19 – Nov. 25

Mid-Term Test: 30% October 25

Final Exam: 50% December 8 – 22.

The Dynamic Earth and Space GeodesyEATS 1010 3.0 [Fall 2011]

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EATS 1010 3.0 Lab. Timetable(Fall 2011)

Group Day Time Lab 1 Lab 2 Lab 3 Lab 4 Lab 5Planet Minerals Plate GPS SeismologyEarth Tectonics

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1 M 11:30 Sept. 19 Oct. 3 Oct. 24 Nov. 7 Nov. 212 M 2:30 Sept. 19 Oct. 3 Oct. 24 Nov. 7 Nov. 21

3 T 11:30 Sept. 20 Oct. 4 Oct. 25 Nov. 8 Nov. 224 T 2:30 Sept. 20 Oct. 4 Oct. 25 Nov. 8 Nov. 22

5 W 11:30 Sept. 21 Oct. 5 Oct. 26 Nov. 9 Nov. 236 W 2:30 Sept. 21 Oct. 5 Oct. 26 Nov. 9 Nov. 23

7 R 11:30 Sept. 22 Oct. 6 Oct. 27 Nov. 10 Nov. 248 R 2:30 Sept. 22 Oct. 6 Oct. 27 Nov. 10 Nov. 24

9 F 8:30 Sept.23 Oct. 7 Oct. 28 Nov. 11 Nov. 2510 F 11:30 Sept. 23 Oct. 7 Oct. 28 Nov. 11 Nov. 25

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Attendance

Lectures

- Notes are essential.

Text only covers about 50% of material

Laboratory Sessions

- Mandatory – zero tolerance

- Change of lab group only with permission of lab. coordinator.

- Lab exercises must be submitted to your group TA. Otherwise no mark.

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galaxy

galaxy cluster

galaxy cluster

galaxy

quasar

quasar

quasar

quasar

The Visible Universe

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Film: Powers of 10

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There are 100 billion "Suns" in a galaxy like our own Milky Way Galaxy.

Astronomers can see billions of galaxies.

The Sun

Photograph from the Hubble space telescope.

Galaxies

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The Milky Way Galaxy as seen edge on from the Solar System

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The Milky Way

On a clear dark night With telescope and time exposure

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Our solar system consists of an average-size star we call the Sun; the planets Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune; and the dwarf planet Pluto.

Our Solar System

It also includes: the satellites of the planets; numerous comets, asteroids, and meteoroids; and the interplanetary medium.

Sun

Mer

cury

Venus

Earth

Mar

s

Jupiter Saturn

Uranus Neptune

Pluto

Relative sizes of planets

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A cloud of interstellar gas/dust, the "solar nebula", including material formed in previous generations of stars, is disturbed (for example, by the shock wave from a nearby supernova).

The “Nebular Hypothesis”

Formation of the Solar System

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The collapsing, spinning nebula begins to flatten into a rotating pancake.

Formation of the Solar System

1. Contraction: The cloud starts collapsing under its own gravity.

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2. A Protostar forms in the centre, when the core becomes dense enough; later will become the Sun.

3. Dust grains stick to each other and sweep their paths, forming larger particles (Planetesimals).

4. Orbital paths are cleared.

5. The Sun and its planets all spin in the same direction.

Formation of the Solar System

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Within the core of the Sun: temperatures exceed 15,000,000° C

and pressure is 340 billion times the atmospheric

pressure at Earth's surface.

Conditions are so intense that nuclear fusion takes place creating new elements.

The Sun

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Nuclear Fusion in the Sun

Four hydrogen nuclei get fused into one helium nucleus,

Accompanied by the emission of neutrinos and release of energy:

4 H1 He4 + neutrinos + energy

H1 is the nucleus of a hydrogen atom (one proton)

He4 is the nucleus of a helium atom (two protons and two neutrons)

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The nucleus of the resulting helium atom is about 0.7 percent less massive than the four component protons.

During the fusion of hydrogen, approximately 0.7% of the mass of hydrogen is converted into energy.

Conversion of Mass into Energy

E = mc2

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Fast-moving ions can escape the Sun's gravitational attraction. Moving outward at hundreds of kilometres/second, these positive and negative charges travel to the farthest reaches of the solar system.

They are called the solar wind.

The Solar Wind

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Bursts of solar wind accompany solar prominences (similar to nuclear explosions) which extend millions of km into space.

Solar Prominences

SolarProminence

Earth

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Interstellar Distances

• The Sun is massive – 99.9% of mass.• The planets are relatively minute: - Jupiter makes up most of the remaining 0.1%.

• The next nearest star appears as a point of light.• Similarly, from the nearest star, our Sun would appear as

a point of light in the night sky- the planets of our Solar System would not be visible. - similarly planets of other stars are not visible to us, but must exist [detected by wobbles of star due to gravity of orbiting planets].

• Distances between the stars are enormous.

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A new unit of distance to measure interstellar space

Light Year:

The distance light travels in a year, travelling at a speed of 300,000 kilometres per second;

1 light-year is equivalent to 9.46053 x 1012 km ( almost ten trillion km).

• The Sun's nearest known stellar neighbour is a star called Proxima Centauri, at a distance of 4.3 light years away (i.e., 4.3 LY).

• Some Quasars are more distant than 10 billion LY.

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The Solar System is Small

Solar System from a Cosmic Perspective

Facts:1. Average distance from the Sun to Neptune is 4.5 x 109 km

2. Distance from the Sun to the nearest star is 4.1 x 1013 km (~ 9000 x distance from Sun to Neptune)

3. The Sun is one of 1022 similar stars.

4. On a cosmic scale the Solar System is microscopic.

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The Solar System is Large

Solar System from an Earth Perspective

Facts:1. The Diameter of Earth is 12.8 x 103 km (DEarth)

2. The distance from the Sun to Earth is 1.496 x 108 km or about 12,000 x DEarth.

3. The diameter of Neptune’s orbit is 700,000 x DEarth.

4. On an Earth scale the Solar System is vast.

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A new unit of distance to measure interplanetary space

Astronomical Unit (AU) : The average distance from the Earth to the Sun; 1 AU = 149,597,870 kilometres (~150 million km)

1 LY= 63,240 AU.

We can measure distances within the solar system in units of AU’s.

e.g., The distance from the Sun to Earth is 1 AU The distance from the Sun to Mars is 1.5 AU

The distance from the Sun to Venus is 0.72 AU