Earthquake is one of the natural disasters that can cause a lot of damage and even loss of casualties. If the earthquake has enough strength. Even earthquakes can cause other disasters such as tsunamis, volcanic eruptions and landslides. The greater the level of damage to the infrastructure that may be caused. See also natural disasters in Indonesia.
Earthquake disasters that occur in Indonesia are mostly natural disasters caused by natural factors. But in reality, earthquakes are not only caused by natural factors. There are several non-natural factors that can cause earthquakes. Then, what are the causes of an earthquake? Here are 13 causes of earthquakes in Indonesia.
1. Indonesia in Pacific Ring of Fire
The Pacific Ring of Fire is a term used to name a region that often experiences active volcanic eruptions and earthquakes. The Ring of Fire area covers around the basin of the Pacific Ocean. This area surrounded by the Ring of Fire has a horseshoe shape.
The length of the area included in the Pacific fire ring is 40,000 km. Of the approximately 90 percent of earthquakes that have occurred so far, 81 percent have occurred in areas included in the Pacific fire ring.
The following are land and sea areas that belong to the Pacific fire ring sorted from the southwest which means anticlockwise
(1) New Zealand, (2) Kermadec Trench, (3) Tonga Trench, (4) Bougainville Trench, (5) Indonesia, (6) Mount Merapi, (7) Philippines, (8) Philippine Trench, (9) Trench Yap, (10) Mariana Trench, (11) Izu Bonin Trench, (12) Ryukyu Trench, (13) Japan, (14) Mount Fuji, (15) Japanese Trench, (16) Trench Kurile, (17) Kamchatka, (18) Aleutia Islands, (19) American Cordillera, (20) Alaska (21) Pacific Coast Range, (22) ) British Columbia, (23) Cascade Mountain Range, (24) Mount St. Hellens, (25) California, (26), Mexico, (27) Trenches of Central America, (28) Guatemala, (29) Nicaragua, (30) Colombia, (31) Ecuador, (32) Peru, and (33) Trenches Peru – Chili Trench.
2. Indonesia’s located in Alpine Belt
In addition, 17 percent of the largest earthquakes or around 5-6 percent of earthquakes that occurred in the world occurred in the Alpine belt area. Both the Pacific fire ring and the Alpine belt, Indonesia is included in its path.
Whereas the regions included in the Alpine belt are as follows : Java, Sumatra, Himalayas, Mediterranean, Atlantika. Based on the names of the regions that belong to the Pacific Ring of Fire and the Alpine Belt, Indonesia is a region that belongs to both.
However, despite its vulnerability to volcanic eruptions and earthquakes, the existence of Indonesia in the Pacific ring of fire and Alpine belt has made the territory of Indonesia has fertile land.
3. Indonesia is at the meeting of 3 plates of Earth
The earth slabs surrounding Indonesia are the Pacific plate, Eurasian plate, and Indo-Australian plate. Earthquakes caused by the plates of the earth occur if the plates shift, break, or even occur.
In addition to the earthquake, especially if there is a collision, it can cause a tsunami after the earthquake. Examples are the 2004 earthquake and tsunami that occurred in Aceh.
Some areas in Indonesia that are prone to earthquakes and tsunamis include Aceh, North Sumatra, Lampung, Banten, Bali, southern East Java, Fak-Fak and Yapen regions in the Papua region, and many more. You may see also historical earthquakes in Indonesia
4. Located at the convergent boundary of the Sunda plate and the Indo-Australian plate
Earthquakes are common in Sumatra because the island is at the convergent boundary where the Sunda Plate is subducted under the Indo-Australian Plate. This plate moves tilted at a speed of 60 mm per year and its right hemisphere component is driven by strike-slip faults on the island of Sumatra, especially in the large fault of Sumatra.
On July 2, 2013, a 6.1 magnitude earthquake rocked the province of Aceh on the Indonesian island of Sumatra. This earthquake was caused by a Sunda plate which was subducted with an Indo-Australian plate.
The movement of the plates resulted in the earthquake in Sumatra being rocked. In addition, several regions of southern Indonesia also experienced earthquakes, from the smallest to the largest.
5. Indonesia’s located between the meeting of two large continental plates and the Semangko fault
The Province of West Sumatra is between the confluence of two large continental plates (the Eurasian plate and the Indo-Australian plate) and the Semangko fracture. Near the plate meeting there is a Mentawai fault. All three are active seismic regions.
According to records, seismic experts in West Sumatra had a 200-year cycle of major earthquakes which at the beginning of the 21st century had entered a period of repeated cycles.
6. Distribution of active faults spread throughout Indonesia
The territory of Indonesia has a great potential for earthquakes because of its position at the confluence of the three main plates of the world.
The plate is the Eurasian Plate, Indo-Australia and the Pacific. From this collision, there are about six active plate collisions which have the potential to trigger strong earthquakes. Read also biggest earthquake in Indonesia
7. Indonesia has many volcanoes
Indonesia is in the Alpin belt region. That is the reason why Indonesia has many volcanoes. A volcano that is still active will emit its magma in the form of eruptions. Eruptions can be light or large eruptions. The area around the volcano is prone to earthquakes.
When the volcano erupts, the surrounding area will experience an earthquake, depending on the size of the eruption.
8. Indonesia has many mining areas
In addition to natural factors, humans can cause earthquakes. Mining activities can damage the natural contours of the earth’s crust, making it unstable and prone to friction. Maybe at the beginning, this situation is not so obvious. But over time the dredging of crops that do not pay attention to environmental rules can cause unusual earthquakes.
9. Drilling of oil and natural gas
Exploitation that occurs on a large scale tends to have a direct effect on the availability of large free space under the earth’s plate. If this empty space experiences instability due to pressure from outside or because of the insistence from within it will undoubtedly cause an extraordinary fracture to be seen after the earthquake stops.
10. Drastic reduction in groundwater
Massive exploitation of groundwater resources can trigger disasters. What’s more when the amount drawn out of the ground is greater than the amount that enters it. This distant difference tends to cause an empty room under the ground. Gravitational / pressure movements or slight impulses can cause faults that initiate unusual earthquakes.
11. Reduced soil density
Soil surface structures that have experienced a deterioration of function will increase the occurrence of earthquakes. Carelessly cutting down trees will further exacerbate the actual function of the land. Coupled with soil pollution by various industrial wastes further reduces its productivity. A barren, unstable and without strong bonding structure by tree roots can magnify earthquakes triggered by landslides.
12. Bomb explosion
Indonesia is one of the countries with the most terrorist targets in the world. Even tourists were afraid to visit Bali because there were bombings in Bali a few years ago. This bomb explosion in Indonesia can cause local earthquakes in the area around the explosion. In addition, bomb explosions can bring down several buildings in the vicinity.
Landslide disasters have many causes. Landslides often occur in mountainous areas. If landslides are large, the surrounding area will experience an earthquake. Although this earthquake is relatively small, the collapse of the land will endanger the houses under it. You can see also history of tsunami in Bali.
Those are 13 Causes of Earthquake in Indonesia. Earthquake can be caused by natural factors and human activities. Indonesia is indeed an area prone to earthquakes because of its location.