How many stars are there

How Many Stars in the Universe?

There are about 1,000,000,000,000,000,000,000 stars in space, or about 10 raised to the 21 (10 21 power, roughly.

Scientists estimate that there are about 1 000 000 000 000 stars in the Milky Way

Submarine earthquake


The moment magnitude scale (abbreviated as MMS; denoted as MW or M) is used by seismologists to measure the size of earthquakes in terms of the energy released.

nderstanding plate tectonics helps to explain the cause of



seismogram is a graph output by a seismograph. It is a record of the ground motion at a measuring station as a function of time. Seismograms typically record motions in three cartesian axes (x, y, and z), with the

Seismic waves

Seismic wave

Seismic wave, vibration generated by an earthquake, explosion, or similar energetic source and propagated within the Earth or along its surface. Earthquakes generate four principal types of elastic waves; two, known as body waves, travel within the Earth,

What to do during earthquake

What Should I Do Before, During, And After An Earthquake?


What to Do Before an Earthquake

  • Make sure you have a fire extinguisher, first aid kit, a battery-powered radio, a flashlight, and extra batteries at home.
  • Learn first aid.

Magnitude Classes

Earthquake Magnitude Classes

Earthquakes are also classified in categories ranging from minor to great, depending on their magnitude.

Class Magnitude
Great 8 or more
Major 7 – 7.9
Strong 6 – 6.9
Moderate 5 – 5.9
Light 4 – 4.9
Minor 3 -3.9

Magnitude Scales

Magnitude Earthquake Effects Estimated Number
Each Year
2.5 or less Usually not felt, but can be recorded by seismograph. 900,000
2.5 to 5.4 Often felt, but only causes minor damage. 30,000
5.5 to 6.0 Slight damage to buildings and other