Study Notes : Movement of the Earth.

Study Notes : Movement of the Earth.

• Rotation: West to east in 24 hours (produces day and night) – Line separating light and dark halves is known as the circle of illumination.
• Revolution: Movement around the sun 365 ¼ days (produces seasons) – Jan 2 Closest to the sun- called Perihelion.
• July 4: Farthest from the sun- called Aphelion.
• Eccentricity: (Produces Ice-age and Global Warming) Shape of the earth’s orbit changes in a cyclic period running between 90,000-1, 00,000 years.
• Precession: This is the conical motion of the axis of the spinning earth, like a spinning top. Takes about 26,000 years to complete one cycle.
• Presently – pointing at Pole star.
• AD 4000- pointing at Alpha cephai
• AD 14,000 – pointing at Star vega
• Summer Solstice: 21st June: Sun overhead at tropic of cancer.
• Winter Solstice: 22nd Dec: Sun overhead at the tropic of Capricorn.
• Vernal Equinox: 21st March.
• Autumn Equinox: 23rd Sep

Moon

Our moon is 1/4th of the size of Earth.

Blue Moon is said to occur when the second full moon appears within the same month.

Highest Mountain on Moon: Leibnitz: 10,660m

Neil Armstrong and Edwin Aldrin: Set foot on the ocean of Tranquillity

In a calendar year, a maximum of seven eclipses can occur( combining solar and lunar eclipses)

Longitude and Latitudes

Any location on Earth is described by two numbers-its latitude and its longitude. If a pilot or a ship's captain wants to specify position on a map, these are the “coordinates" they would use.

Latitudes

• Latitude is a measurement on a globe or map of location north or south of the Equator.Each degree of latitude is approximately 69 miles (111 km) apart; there is a variation due to the fact that the earth is not a perfect sphere but an oblate ellipsoid (slightly egg-shaped). To remember latitude, imagine them as the horizontal rungs of a ladder 
• ("ladder-tude").
• The equator is at 0° latitude and separates Earth’s Northern and Southern hemispheres.
• Locations north of the equator have latitudes between 0° (the equator) and 90° N (the North Pole).
• Locations south of the equator have latitudes between 0° (the equator) and 90° S (the South Pole)

Longitude and Time

• The vertical longitude lines are also known as meridians. They converge at the poles and are widest at the equator (about 69 miles or 111 km apart). Zero degrees longitude is located at Greenwich, England (0°). The degrees continue 180° east and 180° west where they meet and form the International Date Line in the Pacific Ocean. Greenwich, the site of the British Royal Greenwich Observatory, was established as the site of the prime meridian by an international conference in 1884.
• Earth moves 1 degree in 4 minutes.
• Standard meridians differ from Greenwich Meridian by the multiples of 15 degree or 7.5degree.
• Russia have 11 time zones
• USA and Canada have 5 time zones.
• India has one time zone from 82.5 degree east from the Standard time it is near Allahabad 5 hours and 30 minutes ahead of GMT

The International Date Line

1. 180 degrees meridian is the International Date Line

2. A traveller crossing this date line from east to west will lose a day.

3. A traveller going from west to east will gain a day.

Construction of Earth's Interior

• Relative Density= 5.5
• Seismic Waves
• p-waves or primary waves: Also called longitudinal or compressional waves- like sound waves- fastest
• Secondary waves or S-waves: Also called transverse or distortional waves- like water ripples- cannot pass through liquid material.
• Surface Waves or L waves: Long wave length waves- cause most destruction.
• Movement of the Earth.
• Rotation: West to east in 24 hours (produces day and night) – Line separating light and dark halves is known as the circle of illumination.
• Revolution: Movement around the sun 365 ¼ days (produces seasons) – Jan 2 Closest to the sun- called Perihelion.
• July 4: Farthest from the sun- called Aphelion.
• Eccentricity: (Produces Ice-age and Global Warming) Shape of the earth’s orbit changes in a cyclic period running between 90,000-1, 00,000 years.
• Precession: This is the conical motion of the axis of the spinning earth, like a spinning top. Takes about 26,000 years to complete one cycle.
• Presently – pointing at Pole star.
• AD 4000- pointing at Alpha cephai
• AD 14,000 – pointing at Star vega
• Summer Solstice: 21st June: Sun overhead at tropic of cancer.
• Winter Solstice: 22nd Dec: Sun overhead at the tropic of Capricorn.
• Vernal Equinox: 21st March.
• Autumn Equinox: 23rd Sep

Moon

Our moon is 1/4th of the size of Earth.

Blue Moon is said to occur when the second full moon appears within the same month.

Highest Mountain on Moon: Leibnitz: 10,660m

Neil Armstrong and Edwin Aldrin: Set foot on the ocean of Tranquillity

In a calendar year, a maximum of seven eclipses can occur( combining solar and lunar eclipses)

Longitude and Latitudes

Any location on Earth is described by two numbers-its latitude and its longitude. If a pilot or a ship's captain wants to specify position on a map, these are the “coordinates" they would use.

Latitudes

• Latitude is a measurement on a globe or map of location north or south of the Equator.Each degree of latitude is approximately 69 miles (111 km) apart; there is a variation due to the fact that the earth is not a perfect sphere but an oblate ellipsoid (slightly egg-shaped). To remember latitude, imagine them as the horizontal rungs of a ladder 
• ("ladder-tude").
• The equator is at 0° latitude and separates Earth’s Northern and Southern hemispheres.
• Locations north of the equator have latitudes between 0° (the equator) and 90° N (the North Pole).
• Locations south of the equator have latitudes between 0° (the equator) and 90° S (the South Pole)

Longitude and Time

• The vertical longitude lines are also known as meridians. They converge at the poles and are widest at the equator (about 69 miles or 111 km apart). Zero degrees longitude is located at Greenwich, England (0°). The degrees continue 180° east and 180° west where they meet and form the International Date Line in the Pacific Ocean. Greenwich, the site of the British Royal Greenwich Observatory, was established as the site of the prime meridian by an international conference in 1884.
• Earth moves 1 degree in 4 minutes.
• Standard meridians differ from Greenwich Meridian by the multiples of 15 degree or 7.5degree.
• Russia have 11 time zones
• USA and Canada have 5 time zones.
• India has one time zone from 82.5 degree east from the Standard time it is near Allahabad 5 hours and 30 minutes ahead of GMT

The International Date Line

1. 180 degrees meridian is the International Date Line

2. A traveller crossing this date line from east to west will lose a day.

3. A traveller going from west to east will gain a day.

Construction of Earth's Interior

• Relative Density= 5.5
• Seismic Waves
• p-waves or primary waves: Also called longitudinal or compressional waves- like sound waves- fastest
• Secondary waves or S-waves: Also called transverse or distortional waves- like water ripples- cannot pass through liquid material.
• Surface Waves or L waves: Long wave length waves- cause most destruction.