1. Seismic activity
2. Earth's magnetism
3. Volcanoes
4. Mined rocks
5. Gravitational force
6. Meteors
Seismic Activity: Frequency and size of earthquake.
Earth's magnetism: Due to the movement of molten material under the earth's crust.
Volcanoes: A rupture in the crust of a planetary mass object such as Earth, that allows hot lava, volcanic ash & gases to escape.
Mined Rocks: Excavating hard minerals.
Gravitational force: A natural phenomenon.
Meteors: A bright streak of light.

The formation and deformation of landforms on the surface of the Earth is a continuous activity of two broad processes i.e. internal and external. These processes cause stress and deformation on Earth materials and finally bring changes on the surface of the Earth. These are referred as Geomorphic Processes.
The forces that act from the Earth's interior towards the Earth's surface are called Internal processes or Endogenetic processes. These forces build the landscape and create topographic relief.
The forces that act on the surface of the Earth due to natural agents like running water, glacier, wind, waves etc. are called External processes or Exogenetic processes. These external processes tear the landscape down into relatively low elevated plains.

a) Pacific Ring of fire: It is a major area and an arc in the basin of the Pacific ocean where many earthquakes and volcanic eruptions occur.

(b) Earthquake-prone zones (any two): Turkey, Indonesia

(c) Locate any two active volcanoes of the world: Hawaii, Mount Fuji

(d) Himalayas and Alps ranges

GPS works by sending radio signals from satellites to ground stations. The distance between the satellites and station is recorded. Over time, these distances change slightly. Scientists can measure the rate of Tectonic Plate movements by recording the time it takes for ground stations to move a given distance.