Japan issues tsunami advisory after 6.9 magnitude earthquake.

Why in the NEWS?

• A strong earthquake with a preliminary magnitude of 6.9 hit the Kyushu region at 9:19 pm local time in south-western Japan on January 13, according to the Japan Meteorological Agency. 

Key Points:

• It said the quake was centred at a depth of 30 kilometres.
• The earthquake mainly affected Miyazaki Prefecture and nearby Kochi Prefecture.
• The tsunami warning predicted waves up to 1 meter high in the Kyushu region.
• A 20-cm high tsunami was recorded in Miyazaki City.

What is the Ring of Fire?

• The Ring of Fire, also called the Pacific Rim or Circum-Pacific Belt, is a region along the Pacific Ocean where most active volcanoes and earthquakes are recorded.
• 75% of the Earth's volcanoes, or more than 450 volcanoes, are located along the Ring of Fire. 
• 90% of the Earth's earthquakes occur in this region.

Shape and Extent:

• The Ring of Fire is shaped like a half-moon or horseshoe, and it extends for about 40,250 kilometres (25,000 miles). 
• This region forms a large barrier that encircles the coasts of the Pacific Ocean.
• Some of the important places located in the Ring of Fire are Bolivia, Chile, Ecuador, Peru, Costa Rica, Guatemala, Mexico, United States, Canada, Russia, Japan, Philippines, Australia, Papua New Guinea, Indonesia, New Zealand and Antarctica.

Tectonic Plates:

• The Ring of Fire is the meeting point of the Eurasian, North American, Juan de Fuca, Cocos, Caribbean, Nazca, Antarctic, Indian, Australian, Philippine and other smaller plates. 
• All these plates together surround the larger Pacific plate, which forms the centre of the Ring of Fire.

Seismic and Volcanic Activity:

• Earthquakes: 
  • Earthquakes occur frequently within the Ring of Fire, as tectonic plates collide here, and this results in seismic movements.
• Volcanic Eruptions: 
  • There are also many active volcanoes in this region, which erupt frequently due to pressure and heat inside the Earth.

Climate Change and the Ring of Fire: 

• Although the movements of the Ring of Fire are primarily caused by tectonic plates, climate change has exacerbated the effects of these events. 
• Global warming, rising ocean temperatures, and changes in weather patterns can increase the intensity and frequency of natural disasters.

Impact of the Ring of Fire on Environment and Human Life:

• Natural Disasters: 
  • Earthquakes and volcanic eruptions in the Ring of Fire cause many natural disasters that can cause massive losses. 
• Tsunami Hazards: 
  • When earthquakes under the Ring of Fire occur under the ocean, it can also generate tsunamis that affect coastal areas.
• Volcanic Ash and Gas: 
  • During volcanic eruptions, toxic gases and ash are emitted into the air, which can have a negative impact on the environment and human health.

Major incidents that occurred in the Ring of Fire:

• The 2011 earthquake and tsunami in Japan, which killed nearly 16,000 people.
• The 2004 earthquake and tsunami in Indonesia, which affected more than 200,000 people.
• The 2010 8.8 magnitude earthquake in Chile, which killed more than 500 people.

Existence of Volcanoes in the Ring of Fire and the Subduction Process:

Existence of Volcanoes: 

• Volcanoes in the Ring of Fire exist mainly due to the movement of tectonic plates. 
• This region is one of the most active volcanic regions on Earth, with extreme earthquakes and volcanic eruptions.

Subduction Process: 

• Many volcanoes are caused by a process called subduction. 
• This process occurs when two tectonic plates collide, and one plate goes under the other. 
• This collision creates deep trenches (subduction zones), and results in volcanic activity.

Description of the Subduction Process:

• When an oceanic plate (such as the Pacific Plate) goes under another plate, it is very hot. 
• During this process, that part of the plate is pushed into the mantle and heats up.
• This heat causes volatile elements to be introduced from the plate, forming magma.
• This magma then rises up through the overlying plate, and as it reaches the surface, it is released in the form of volcanic magma, causing volcanoes and eruptions.

Subduction Zones in the Ring of Fire:

• Most of the subduction zones are located in the Ring of Fire. 
• This is the place where the collision between two tectonic plates pushes one plate under the other.
• These subduction zones of the Ring of Fire are responsible for volcanic activity and many active volcanoes are located on these zones.

Cause and Effect:

• A large number of volcanoes are found here due to subduction in the Ring of Fire. 
• Due to this, this region is one of the most sensitive and active regions for volcanic activity on Earth.
• When plates collide in the subduction zone, it causes earthquakes and volcanic eruptions, which are a constant threat to the countries of the Ring of Fire.