Earth's Movements and Changing Landforms | Footprints Class 7: Book Solutions, Notes & Worksheets PDF Download

Short Answer Questions

Q1.
Ans: The epicentre of an earthquake is the point on the Earth's surface directly above the focus or origin of the earthquake underground.

Q2.
Ans: An active volcano is a volcano that has erupted recently or is expected to erupt in the near future.

Q3.
Ans: Weathering is the process by which rocks are broken down into smaller fragments by the action of atmospheric conditions, such as temperature changes, moisture, and biological activity.

Q4.
Ans: Armchair-shaped depressions formed by glaciers are found in mountainous regions where glaciers have carved out deep hollows in the landscape.

Q5.
Ans: A tarn is a small mountain lake or pool, formed in a cirque excavated by a glacier.

Brief Answer Question

Q1.
Ans: Exogenic forces are external forces acting on the Earth's surface, such as erosion and weathering, while endogenic forces are internal forces, such as volcanic activity and plate tectonics.

Q2.
Ans: The Theory of Continental Drift, proposed by Alfred Wegener in the early 20th century, suggests that the continents were once joined together in a single landmass called Pangaea and have since drifted apart to their current positions.

Q3.
Ans: Certain movements, such as the collision of tectonic plates, can lead to the folding of rock layers, resulting in the formation of fold mountains.

Q4.
Ans: A volcano is a vent or opening in the Earth's crust through which molten rock, ash, and gases are ejected during an eruption.

Q5.
Ans: Old fold mountains, such as the Appalachians, are formed millions of years ago and have rounded peaks and gradual slopes. New fold mountains, such as the Himalayas, are still being formed and have pointed peaks and steep valleys.

Detailed Answer Questions

Q1.
Ans: The upper course of a river is characterized by steep gradients and features such as waterfalls and gorges. The middle course has a gentler slope and features like meanders and floodplains. The lower course is near sea level and has features like deltas and estuaries.

Q2.
Ans: Glacial landforms include cirques, aretes, and horns formed by erosion, as well as moraines and drumlins formed by deposition.

Q3.
Ans: Beaches are formed by the deposition of sand and pebbles by waves. Sandbars are formed when sand is deposited offshore and accumulates to form a ridge. Lagoons are formed when a sandbar cuts off a part of the sea, creating a shallow, sheltered body of water.

Q4.
Ans: Wind shapes desert landforms by erosion, creating features like mushroom rocks and arches, as well as by deposition, forming sand dunes and loess deposits.