Sticky acid lava on cooling, solidifies and hardens before flowing long distances. Sometimes it has become possible to control or divert the lava flow by constructing retaining walls or by some provision to chill the front of the lava flow with water.
The effects of eruption on the atmosphere are precipitation of salty toxic or acidic matter. World Distribution of Volcanoes: Generally the vent opens out to a depression called crater at the top of the volcano.
Between these two main types viz. In fact, volcanic eruptions are very closely associated with the plate boundaries. The image below shows how it appears as if it were migrating eastward.
It depends on how much rainfall the area receives, as rainfall is the main way you clear ash off the land. These are called seamounts. Dormant volcanoes are The nature of volcanic hazards essay which become quiet after their eruptions for some time and there are no indications for future eruptions but suddenly they erupt very violently and cause enormous damage to human health and wealth.
Vesicles are small cavities in lava, frozen bubbles of gas. The weaker zones of the earth are represented by folded mountains western cordillera of North America, Andes, mountains of East Asia and East Indies with the exceptions of the Alps and the Himalayas, and fault zones.
Visuvious volcano is the best example of dormant volcano which erupted first in 79 A. A peleean eruption named after the eruption of Mt. Himalayas and the North-eastern mountain regions 2. Volcanoes also release chlorine and carbon dioxide.
When magma rises, it may encounter groundwater causing enormous phreatic, i. From the geological historical view point, volcanic activity was crucial in providing to the earth a unique habitat for life.
This belt includes the volcanoes of Alpine mountain chains and the Mediterranean Sea and the volcanoes of fault zone of eastern Africa. Earth scientists continued to focus on the physical causes of disasters.
Much of this variation in composition depends upon what happens to the basalt magma once it leaves the mantle and begins its upward journey through the crust. Explosive eruptions cause burning clouds of gas with scraps of glowing lava called nuees ardentes.
They are formed by the expansion of the steam and other gases beneath the hardened crust of a lava. Natural hazards are elements of circumstances in the natural environment that have the potential to cause harm to people or property or both.
The chart in Fig. They can permanently change a landscape. This is also known as ropy lava. This splitting and lateral spreading of plates creates fractures and faults transform faults which cause pressure release and lowering of melting point and thus materials of upper mantle lying below the mid-oceanic ridges are melted and move upward as magmas under the impact of enormous volume of accumulated gases and vapour.
As basaltic magma changes composition toward rhyolite the volatiles become concentrated in the silica-rich magma. On the basis of size pyroclastic materials are grouped into: Either melt water from snow or rain at the summit of the volcano can mix with the volcanic ash and start a deadly mud flow called as lahar.
The basic subdivision is based on the proportions of the gas, liquid and solid components, which can be represented on a triangular diagram. Besides, some volcanoes are also found in intraplate regions e. Many of the gases escaping from the vents may be poisonous, such as hydrogen sulphide and carbon monoxide which are suffocating and may settle at low places in the topography.With reference to examples, discuss the ways in which the nature of volcanic hazards can vary Events that cause death, injury and damage to property and infrastructure are known as natural hazards.
Volcanic eruptions can swiftly become natural hazards which can quickly lead to major loss of life and widespread damage.
Essay about. Environmental hazards Essay Sample. The whole doc is available only for and the erosive power of flowing water and ice. The Yellowstone Supervolcano is the volcanic field which produced the past three supereruptions from the Yellowstone hotspot.
he was surrounded by the beauty and tranquillity of nature.
Frost, through his poems. Change is the law of nature. It is continuous process that goes on uninterruptedly involving phenomena, big and small, material and non-material that make over physical and socio-cultural environment.
Essay on Environmental, Hazards and Disasters. Volcanic eruptions. vi. Tsunamis. vii. Drought (ii) Man-Made Hazards. Essay on Volcanoes | Geology. Article shared by: ADVERTISEMENTS: Essay on the Volcanic Hazards Essay on the Volcanoes and Atmospheric Pollution; ADVERTISEMENTS: The nature of a volcanic eruption is determined largely by the type of materials ejected from the vent of the volcano.
Volcanic eruptions may be. Essay on Volcanoes: Top 7 Essays on Volcanoes| Disasters | Geography. Article shared by: Classification on the Basis of the Nature of Volcanic Eruptions: Volcanic eruptions occur mostly in two ways viz.: (i) Violent and explosive type of eruption of lavas, volcanic dusts, volcanic ashes and fragmental materials through a narrow pipe and.
Essay on Natural Hazards in India | Geography. Article shared by: Volcanic eruptions (v) Cosmic collisions. Based on the causes, nature and character, drought can be classified as: (i) Hydrological drought—when water level of the surface and ground falls.Download