LATITUDE
& LONGITUDE
Complete, source-based exam notes covering Earth's shape, rotation and revolution, axial inclination, latitude and longitude, important parallels and meridians, IST, GMT, International Date Line, great circles, hemispheres, seasons, eclipses, heat zones, tides and tidal energy.
1. Quick Overview
Mean radius of Earth
Axial inclination
Total latitudes in source
Total longitudes in source
23 h 56 min 4 sec
365 days 6 h 9 min
29.8 km/sec
Complete source coverage target: 100%
Visual Library
Responsive conceptual diagrams reconstructed from the uploaded pages. They are study visuals, not scale maps.
2. Earth's Shape
The source describes Earth's shape as Geoid or Oblate Spheroid: slightly flattened at the top and bottom and bulged at the centre/equator.
6378 km
6357 km
6371 km
40,007.863 km
40,075 km
40,040 km
- Equatorial radius > polar radius.
- Equatorial circumference > polar circumference.
- Equatorial speed > polar speed.
Geodesy
Science of accurately measuring and understanding Earth's geometric shape, orientation in space and gravity field.
3. Rotation & Revolution of Earth
Rotation
- Earth rotates on its axis from west to east (anticlockwise).
- One rotation = 23 h 56 min 4 sec.
- Causes day and night.
- Rotational speed is maximum at equator and minimum at poles.
Revolution
- Earth revolves around the Sun in an elliptical orbit.
- 1 revolution = 365 days 6 h 9 min.
- Orbital speed = 29.8 km/sec.
- Seasons result from revolution plus axial tilt.
- Mercury has maximum orbital speed; Neptune minimum, as stated in source.
Earth–Sun and Earth–Moon Distances
| Term | Meaning | Source detail |
|---|---|---|
| Perihelion | Earth is closest to Sun | January 3; 147 million km |
| Aphelion | Earth is farthest from Sun | July 4; 152 million km |
| Perigee | Moon closest to Earth | Moon appears large in sky |
| Apogee | Moon farthest from Earth | Tide-raising force is smaller; tidal ranges less than average |
4. Latitude & Longitude
Latitude
- Imaginary horizontal lines running east–west.
- Angular distance of a place from the Equator.
- Distance between each latitude is same.
- 1° latitude ≈ 111 km.
- Total latitudes: 181.
- Latitude circles: 179.
- Parallel circles from equator to poles are called parallels of latitude.
Longitude
- Imaginary vertical lines running north–south.
- Least distance at poles; maximum at equator.
- Maximum equatorial distance stated: 111.32 km.
- Total longitudes: 360.
- Part between two longitudes is called a “Gore” in source.
Important Latitudes
| Latitude | Value |
|---|---|
| Equator | 0° — largest latitude; radius at equator 6378 km |
| Tropic of Cancer | 23.5°N |
| Tropic of Capricorn | 23.5°S |
| Arctic Circle | 66.5°N |
| Antarctic Circle | 66.5°S |
| Poles | Smallest latitude |
Important Longitudes
- Prime Meridian: 0° longitude; source also associates it with Greenwich Mean Time.
- International Date Line: 180° longitude.
5. Time, GMT & Indian Standard Time
GMT / Prime Meridian
- Source says GMT passes through Europe, Africa and Antarctica.
- Also known as Prime Meridian in the source.
IST
- 82.5° longitude.
- Source says IST passes through 5 Indian states.
- States listed: Uttar Pradesh, Madhya Pradesh, Chhattisgarh, Odisha and Andhra Pradesh.
| Country / region | Time zones stated in source |
|---|---|
| USA | 6 |
| India | 1 |
| China | 1 |
| Russia | 11 |
| France | 13 — maximum in source |
6. Great Circle & Hemispheres
Great Circle
- Largest possible circle that can be drawn around a sphere.
- Divides Earth into two equal hemispheres.
- All longitudes are considered great circles, while only one latitude is considered a great circle: the Equator (0°).
- Source states it gives the shortest distance between two points.
Equal Division of Earth
| Reference | Division |
|---|---|
| Equator | Northern Hemisphere + Southern Hemisphere |
| Prime Meridian | Eastern Hemisphere + Western Hemisphere |
International Date Line
- Imaginary zig-zag line through the Pacific Ocean from where the date changes.
- Source example: crossing eastbound from Japan to USA → date is subtracted by 1 / traveller gains a day; vice versa in the opposite direction.
7. Solstice & Equinox
Axial Inclination
23.5°Inclination of Earth on its axis.
Orbital Inclination
66.5°Inclination of Earth's orbital plane, as stated in source.
Equinox
Time when the Sun's apparent path crosses the equator, making day and night approximately equal in length.
| Event | Date | Source explanation |
|---|---|---|
| Vernal Equinox | 21 March | Equinox |
| Summer Solstice | 21 June | Longest day in Northern Hemisphere; vertical rays over Tropic of Cancer; Northern Hemisphere gets more heat; continuous daylight at North Pole for 6 months. |
| Autumnal Equinox | 23 September | Equinox |
| Winter Solstice | 22 December | Shortest day in Northern Hemisphere; vertical rays over Tropic of Capricorn; Southern Hemisphere gets more heat; continuous daylight at South Pole for 6 months. |
8. Eclipses, Moon Phenomena & Syzygy
Solar Eclipse
Moon passes between Earth and Sun, casting a shadow on Earth. Source: occurs during a new moon (Amavasya).
Lunar Eclipse
Earth passes between Moon and Sun, casting a shadow on Moon. Source: occurs during a full moon (Purnima).
Red Moon
Source explains that when Earth blocks sunlight, blue light scatters more while red light reaches the Moon.
Blue Moon
Source: occurs when there are two full moons within a single calendar month.
Super Moon
Moon's orbit is closest to Earth during a full/new moon; Moon appears bigger than normal.
Syzygy
Sun, Moon and Earth aligned in a straight line. Two types listed: Syzygy Conjunction and Syzygy Opposition.
9. Heat Zones of Earth
Torrid Zone
Receives direct overhead rays; hottest zone; located between the Tropics.
Temperate Zone
Between Tropic of Cancer and Arctic Circle, or Tropic of Capricorn and Antarctic Circle; receives slanting rays.
Frigid Zone
Coldest region; source states daylight for 6 months and night for 6 months due to Earth's tilt.
10. Tides
Tides are periodic rise and fall of ocean water levels caused by gravitational pull of the Moon and Sun on Earth's oceans.
Spring Tide
Occurs when Earth, Sun and Moon are aligned along a straight line.
Neap Tide
Occurs when Earth, Sun and Moon are in perpendicular alignment.
Flood & Ebb
- Low → high tide = flood tide / flow.
- High → low tide = ebb tide.
| Type | Pattern | Time gap stated in source |
|---|---|---|
| Diurnal | One high + one low tide per day | One high to one low: 6 h 12 min |
| Semi-diurnal | Two high + two low tides per day | Between two high & two low tides: 12 h 25 min |
11. Tidal Energy
Where continental shelves are wide.
Funnel-shaped geographical features.
12. Important Terms
| Term | Simple explanation |
|---|---|
| Geoid / Oblate spheroid | Earth's source-described slightly flattened and equatorially bulged shape. |
| Geodesy | Science of measuring Earth's shape, orientation and gravity field. |
| Latitude | Angular distance north or south of the Equator. |
| Longitude | Angular position measured east or west from the Prime Meridian. |
| Perihelion | Earth closest to Sun. |
| Aphelion | Earth farthest from Sun. |
| Perigee | Moon closest to Earth. |
| Apogee | Moon farthest from Earth. |
| Great Circle | Largest circle around a sphere. |
| Equinox | Sun's apparent path crosses equator; day and night approximately equal. |
| Solstice | Astronomical event producing longest/shortest day conditions. |
| Syzygy | Sun–Moon–Earth straight-line alignment. |
| Spring Tide | Tide during straight-line alignment. |
| Neap Tide | Tide during perpendicular alignment. |
13. Key Facts
Equatorial radius
Polar radius
Axial inclination
Prime Meridian / Equator reference values
Tropic of Cancer
Tropic of Capricorn
Arctic Circle
Antarctic Circle
International Date Line
IST longitude in source
Orbital speed
Two high/two low tide interval stated
14. Tables & Comparisons
| Latitude | Longitude |
|---|---|
| Horizontal, E–W | Vertical, N–S |
| Angular distance from Equator | Position relative to Prime Meridian |
| 1° ≈ 111 km | Distance varies; maximum at Equator in source |
| 181 total in source | 360 total in source |
| Rotation | Revolution |
|---|---|
| West → east | Around Sun in elliptical orbit |
| 23 h 56 min 4 sec | 365 days 6 h 9 min |
| Day & night | Seasons with axial tilt |
| Spring Tide | Neap Tide |
|---|---|
| Sun–Earth–Moon aligned | Sun–Earth–Moon perpendicular |
| Stronger tidal range concept in source context | Smaller tidal range concept in source context |
15. Common Confusions
Perihelion vs Perigee
Perihelion = Earth–Sun closest. Perigee = Moon–Earth closest.
Aphelion vs Apogee
Aphelion = Earth farthest from Sun. Apogee = Moon farthest from Earth.
Latitude vs Longitude
Latitude runs east–west and measures north/south angular distance from Equator. Longitude runs north–south and is associated with east/west position.
Equinox vs Solstice
Equinox → approximately equal day/night. Solstice → longest/shortest day conditions.
Solar vs Lunar Eclipse
Solar: Moon between Sun and Earth. Lunar: Earth between Sun and Moon.
Spring vs Neap Tide
Spring = straight-line alignment. Neap = perpendicular alignment.
Flood vs Ebb
Flood = low to high. Ebb = high to low.
16. Exam Focus
- Earth's shape: Geoid / Oblate spheroid.
- Equatorial radius 6378 km; polar radius 6357 km; mean radius 6371 km.
- Rotation: west to east; 23 h 56 min 4 sec; day/night.
- Revolution: 365 days 6 h 9 min; seasons with axial tilt.
- Perihelion January 3; Aphelion July 4 — source.
- Axial inclination 23.5°; orbital inclination 66.5°.
- Equator 0°; Cancer 23.5°N; Capricorn 23.5°S; Arctic 66.5°N; Antarctic 66.5°S.
- Prime Meridian 0°; International Date Line 180°.
- IST longitude: 82.5° in source.
- Great Circle: largest circle; Equator is the only latitude treated as a great circle.
- June 21 Summer Solstice; December 22 Winter Solstice in source.
- Solar eclipse = new moon; lunar eclipse = full moon in source.
- Spring tide = alignment; neap tide = perpendicular alignment.
- Diurnal = one high + one low; semi-diurnal = two high + two low.
- Tidal energy can generate electricity from predictable tidal rise/fall.
17. Quick Revision
Read shape, motion, latitude & longitude.
Recall all important latitudes/longitudes.
Revise time, great circle, seasons.
Eclipses + tides + MCQs.
Full recall + retest.
One-Page Revision Sheet
18. Interactive Practice Test
15 source-based MCQs. No unsupported facts added.
MY NOTES
These fields are separate from AI-generated notes and are saved locally in your browser.
Study Timer
25:0025-minute default session.
NOTE QUALITY CHECK
- Source pages analyzed: 9 / 9
- Unreadable pages: None identified.
- Major topics covered: Earth's shape, motion, latitude, longitude, important lines, time zones, great circles, hemispheres, seasons, eclipses, heat zones, tides and tidal energy.
- Diagrams/tables detected: Yes — source infographics/maps/diagrams on pages 1–9 reviewed and key concepts reconstructed as responsive visuals.
- Questions generated: 15 MCQs.
- Potential ambiguities: Some numerical values, country time-zone counts and date/terminology statements are reproduced as stated in the source. Verify against the prescribed textbook if your exam uses a different convention.
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