Thursday, November 27, 2025

Why some volcanoes spew gas and ash, others lava ??

 After laying dormant for 12,000 years, the Hayli Gubbi in northeastern Ethiopia erupted on Sunday.


But instead of hot, molten lava  flowing down the mountain side, thick plumes of ash and gaseous matter dominated the eruption.


The difference in whether a volcano erupts with flowing lava or violent bursts of ash is determined by these  ----


Magma Viscosity  (  thickness  )

                   Viscosity is fluid's resistance to flow. It says how " sticky " it is.

                    It is primarily controlled by magma's silica (  SiO2  ) content.


Low viscosity gives "  Runny magma  "  having less silica.

High viscosity gives  "  Sticky magma  " having high silica.


Magma contains dissolved gases  (  mostly water vapour and carbon dioxide  ).


As magma rises, pressure decreases.  These gases try to escape and form bubbles.


In low viscosity magma, magma flows out as lava.


But in high viscosity magma, sticky magma traps the gas bubbles, preventing them from escaping.


The pressure builds up immensely.


When the pressure exceeds the strength of surrounding rock, the eruption is violent and explosive.


It shatters the magma into tiny pieces of rock, mineral and glass called volcanic ash.


While Hayli Gubbi is built from low viscosity magma, it was dormant for 12,000 years  !!!


This dormancy developed a high gas pressure and resulted in explosive eruption that produced a large ash plume.



Now the ash cloud has surpassed Himalayas and moving towards Japan   !!!

Longest rivers and countries where they flow

 Here is the list of rivers and where they are located 



1.  Nile river 

                   Flows through Egypt, Sudan, South Sudan, Burundi, Rwanda,  Tanzania, Uganda, Democratic Republic of Congo, Kenya, Ethiopia, Eritrea 



2.  Amazon river

                  Flows through Brazil, Peru, Columbia, Venezuela, Ecuador, Bolivia,  Guyana 




3.  Yangtze river 

                Flows through China 



4.  Mississippi - Missouri river 

                    Flows through United States of America 



5.  Yenisei river

                    Flows through Russia and Mongolia 

Wednesday, November 26, 2025

What are neutron stars ??

 A neutron star is an incredibly dense celestial object formed from the remains of a massive star that has undergone a     supernova explosion.




How a neutron star formed??

A massive star runs out of fuel, collapses and explodes into a supernova.

The star 's core collapses causing protons and electrons to combine with neutrons.





Neutron stars are extremely dense.

They are relatively small having diameter of 10   -  20   kilometers.

They have incredibly strong magnetic field.

They rotate rapidly emitting beams of radiation that sweep through universe.

Wild facts about lions

1.  Lions are the only big cats that live in groups called  ' prides  '.


2.  There are two sub species of lions in the world.

        Asiatic lions

        African lions


3.  Asiatic lion is found in a small population in Gir Forest, Gujarat.


4.  Lion cubs are born with spots that helps them to camouflage in long grass.


5.  Lion's mane helps it appear larger and more threatening towards potential rivals.


6.  Lions need a lot of food to keep them going. 

      They can eat upto 40 kg in one meal  !!!


7.  Lions are clever hunters.

     They choose to hunt at night or during storms where their prey is               unlikely to see or hear them.


8.  Lions are the only one in cat species to roar together.

Tuesday, November 25, 2025

Which is the highest and lowest altitude in India ??

 Highest altitude in India 


 Highest altitude in India is   Kanchenjunga .


It is the third highest mountain peak in the world.

It is located at border between Sikkim and Nepal.

It influences regional climate pattern.

It is home to many glaciers from which rivers are born.


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Lowest altitude in India 


Lowest altitude in India is found at  Kuttanad ,  Kerala 


This is the region where farming is practiced below sea level.

It is primarily a river Delta.

Geographical formation of Kuttanad is part of extensive alluvial plains formed by sediment deposits from western ghats carried by rivers.