Earth’s Relief and Features

Coastal zones are areas where the emerged land surface meets the sea. These zones exhibit various landforms, including capes, gulfs, peninsulas, estuaries or fjords, and islands.

• Cape: A part of the land that extends into the sea. A very small cape is called a point.
• Gulf: An inlet of the sea along the coast. A small gulf is called a bay.
• Peninsula: An area of land surrounded by water on all sides except for one, which is called an isthmus.
• Estuary or Fjord: A deep, narrow valley flooded by the sea.
• Island: A piece of dry land surrounded by water on all sides.

Continental relief is varied. The main landforms are plateaus, mountains, plains, and basins or depressions.

• Plateaus: Also called mesas or shields, plateaus are extensive, flat or undulating areas with an average altitude of 650 meters above sea level. Some of Earth’s highest plateaus include the Tibetan Plateau and Pamir in Asia, the Kalahari Plateau and Lake Victoria Plateau in Africa, the Brazilian Plateau in South America, and the Great Artesian Basin in Australia.
• Mountains: The highest landforms. They can occur in isolation but generally form mountain ranges and mountain systems. The world’s highest mountain range is the Himalayas.
• Plains: Low and flat areas with minimal irregularities on their surfaces. They are located along coasts and in the basins of major rivers. A significant example is the Great European Plain, stretching from the Ural Mountains to the coast of France.
• Basins or Depressions: Recessed areas between highlands and mountains, often traversed by a river, such as the Amazon Basin or the Mississippi Basin.

The Earth’s crust presents various roughnesses and deformations, taking different forms on continents and ocean floors.

Continents are large landmasses surrounded by seas and oceans. There are six continents: Asia, America, Africa, Antarctica, Europe, and Oceania.

Oceans are vast bodies of saltwater. There are five oceans: Pacific, Atlantic, Indian, Arctic, and Southern.

The Earth comprises solids, liquids, and gases grouped into three major spheres: the atmosphere (layer of air surrounding Earth), the hydrosphere (bodies of water), and the lithosphere (rocks and other solids).

The lithosphere is divided into three layers:

• Crust: The thin, outer layer of solid rock. It is divided into continental crust and oceanic crust.
• Mantle: The middle layer of solid or semi-molten rock. It is divided into the upper mantle and lower mantle.
• Core: The innermost layer, representing about 15% of Earth’s total volume. It consists mainly of iron.

What are the four main elements found in the Universe?

Stars, planets, satellites, and nebulae.

What is the name of our galaxy? Which planets are in our solar system?

Our galaxy is the Milky Way. Our solar system consists of eight planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.

Is Earth a perfect sphere? What is its circumference at the equator? List three factors that make it the only planet where, so far, life has been found.

No, Earth is a geoid, flattened at the poles. Its circumference at the equator is 40,077 km. Our planet sustains life due to its protective atmosphere, distance from the Sun, and the presence of liquid water.

What are Earth’s two main movements?

Rotation on its axis every 24 hours and revolution around the Sun every 365 days and 6 hours.

How many time zones is Earth divided into, and what is their extent?

Earth is divided into 24 time zones, each covering 15° of longitude.

What does Earth’s rotation cause? And its revolution? Identify the four main positions in Earth’s revolution and their characteristics.

Rotation causes day and night. Revolution causes the seasons due to varying sunlight incidence on the hemispheres. The four main positions are the two equinoxes (spring and autumn, with equal day and night) and two solstices (summer and winter, with unequal day and night).

What are parallels? Name the most important ones. What about meridians? What is the prime meridian?

Parallels are imaginary lines circling Earth parallel to the equator. The five most important are: the Arctic Circle (66°33’N), Tropic of Cancer (23°27’N), Equator (0°), Tropic of Capricorn (23°27’S), and Antarctic Circle (66°33’S). Meridians are imaginary half-circles running north-south. The prime meridian is the Greenwich Meridian (0°).

Is the following statement correct? Why? “Cuenca is located at 40°04′ west longitude and 02°08′ north latitude.”

It’s incorrect. Latitude is the angular distance from the equator (north or south), while longitude is the angular distance from the prime meridian (east or west). It should be: “Cuenca is located at 40°04′ north latitude and 02°08′ west longitude.”

Besides the land surface, what else is always found on a map?

The legend, compass rose, geographic grid (latitude and longitude lines), and scale.

Which scale is more accurate and detailed: 1:10,000 or 1:100,000? Why?

1:10,000 is more detailed. 1 cm on this map represents 10,000 cm (0.1 km) in reality, while 1 cm on a 1:100,000 map represents 100,000 cm (1 km).