Some Natural phenomena 8 Flashcards
Tornados generally occur in the regions of
Atlantic Ocean
Speed of tornadoes
Weak - 50 to 60 km per hr
Strong - 400 km per hr
Speed of the wind is measured by
Anemometer
Word monsoon derived from the word
Mausam (Arabic - means season)
In America cyclones are referred as
Hurricanes
In Philippines and Japan cyclones are referred as
Typhoon
Gales
Winds moving at high speed
In land , the crust has an average thickness of
40 km
In oceans,the crust has an average thickness of
10-12 km
Mantle length
2900 km (approx.)
Density of mantle
Increases with depth - 3.5 to 5.5 gram/cm3
Mantle contains
Silicate minerals rich in magnesium and iron.
Outer core contains
Iron and nickel in molten state. Also sulphur
Outer mantle thickness
2300 km
Inner core thickness
1300 km
Inner core contains
A solid ball made of iron
Lithosphere
Crust and upper layer of mantle together called
An Earthquake is the fracture in the
LITHOSPHERE
The crust is divided into
7 large plates and several smaller ones
Plate tectonics -
THEORY that tells that the surface of the earth is made of several lithospheric plates.
Himalayas is believed to be formed by the collision of
Eurasian plate and Indian plate.
A fault is
A crack in the Earth’s crust.
Focus (seismology) -
Point where Earthquake occurs
Epicentre situation
Above the focus of the Earthquake ; on the surface.
San Andreas fault is situated in
California
San Andreas Fault marks the boundary between
Pacific plate and North American Plate
Seismograph also called
Seismometer
The output in a seismograph called
Seismogram
Mild Earthquake; Richter scale reading -
0 - 2.9
An increase of 1 on Richter scale means
A 30-fold increase in energy.
Liquefaction
Process by which water saturated soil ; loses strength and acts like a fluid.
Bhuj earthquake , when ?
26 January 2001 in Gujarat (90000 people)
Kashmir earthquake
Struck indo-Pakistan border on 8 October 2005, magnitude- 7.6. (50000 people)
Some earthquakes in Nepal
25 April and 12 May 2015 (7.8-8.1)
Most earthquake prone country
Indonesia
San Andreas fault dimensions
1000 km long
9 metres deep
An Indian state in which earthquake has a great chance of occurring
Gujarat
Tsunami width and speed
Width - 100 to 200 km
Speed - 700 to 800 km/hr
During lightning air is heated to
30,000 °C
Position of charges in a cloud
-ve charges in base
+ve charges in top
How much Electric current flows during a lightning strike
10000 - 20000 amperes
Strobe effect
Brightening and dimming of lightning
