First-year junior high school students have just entered the junior high school campus and are also exposed to geography for the first time. The following is a summary of some key geographical knowledge points. Hope it helps everyone.

1. The Earth and Map

1. The shape and size of the Earth

(1) The Earth is a sphere.

(2) The fleet led by Portuguese navigator Magellan achieved the first human voyage around the earth.

(3) The earth has a surface area of ??510 million square kilometers, a maximum circumference of 40,000 kilometers, an equatorial radius of 6378 kilometers, a polar radius of 6357 kilometers, and an average radius of 6371 kilometers.

2. Latitude and longitude

(1) Latitude: a circle perpendicular to the earth's axis and surrounding the earth.

The latitude lines are of different lengths, and the equator is the largest latitude line.

(2) Longitude: a semicircle that connects the north and south poles and intersects perpendicularly with the latitude.

Meridians are of equal length.

3. Latitude and longitude

(1) The changing pattern of latitude: increasing from the equator (0° latitude) to the south and north poles. The maximum latitude is 90 degrees, at the South Pole and the North Pole.

(2) The latitude north of the equator is called northern latitude, represented by "N"; the latitude south of the equator is called southern latitude, represented by "S".

(3) Taking the equator as the boundary, the earth is evenly divided into two hemispheres: the northern and southern hemispheres. North of the equator is the northern hemisphere, and south of the equator is the southern hemisphere.

(4) The change pattern of longitude: from the prime meridian (0° longitude) to the west and east to 180

(5) The longitude east of the prime meridian is called east longitude , represented by "E"; the longitude west of the prime meridian is called west longitude, represented by "W".

(6) The dividing line between the eastern and western hemispheres is: the longitude circle composed of 20°W and 160°E.

West of 20°W to 160°E belongs to the Western Hemisphere (greater than 20°W or greater than 160°E)

East of 20°W to 160°E belongs to the Eastern Hemisphere (less than 20° W or less than 160°E)

2. Seven continents and four oceans

1. The earth’s surface area is 510 million square kilometers, of which there are six large and countless small land masses. , the larger one is the continent, the smaller one is the island, together they are called the continent, the protruding part extending into the ocean is called the peninsula, and Haiyang is the narrow waterway that connects the two oceans.

2. Continents crossed by the equator: African continent, South American continent.

3. The seven continents arranged by area are Asia, Africa, North America, South America, Antarctica, Europe, and Oceania. The largest area is Asia, the smallest area is Oceania, and the largest area in the world is The island is Greenland.

4. The dividing line of each continent: the dividing line between Asia and Europe: Ural Mountains, Ural River, Caspian Sea, Greater Caucasus Mountains, Black Sea, Turkish Strait, Mediterranean Sea; the dividing line between South America and North America: Panama The canal connects the Atlantic and Pacific Oceans; the dividing line between Asia and Africa: the Suez Canal, connecting the Indian Ocean and the Atlantic Ocean; the dividing line between Europe and North America: the Denmark Strait, connecting the Atlantic and Arctic Oceans; the dividing line between Asia and North America: the White The Strait, connecting the Arctic Ocean and the Pacific; the dividing line between South America and Antarctica: the Drake Strait, connecting the Atlantic and Pacific; the dividing line between Europe and Africa: the Strait of Gibraltar, connecting the Atlantic and the Mediterranean; the dividing line between Asia and Oceania : The Strait of Malacca connects the Indian Ocean and the Pacific Ocean.

3. Distribution of temperature

1. Isotherm: A line connecting points with the same temperature on a map is called an isotherm. On the same isotherm, the temperature at each point equal.

2. Where isotherms are dense, the temperature difference is large; where isotherms are sparse, the temperature difference is small.

3. When the isotherm has a closed shape, if the central temperature is lower than the surrounding temperature, it means that this is a low-temperature center; if the central temperature is high, it means that this is a high-temperature center.

4. The distribution pattern of temperature: (1) Gradually decreases from the equator to the poles (2) The temperature is high at low latitudes and low at high latitudes (3) At the same latitude, the land temperature in summer is high and the ocean temperature is low. In winter, the land temperature is low and the ocean temperature is high (4) In the same place, the temperature is high when the altitude is low, and the temperature is low when the altitude is high (for every 100 meters of altitude increase, the temperature drops by about 0.6°C)

5. Influence on temperature Distribution factors: latitude factors; land and sea factors; terrain factors