Plates in Indonesia – When talking about plates, it cannot be separated from the theory of plate tectonics or the formation of the earth in which the earth was formed due to movement under the earth’s surface. In addition, this theory has become famous around the 1960s. In fact, this theory has replaced earth science which generally uses geological events, such as volcanoes, mountains, and earthquakes.
Then, this theory of plate tectonics consists of the outermost layer of the earth or the lithosphere layer. In this case, this layer of the lithosphere consists of the earth’s crust and mantle which then splits to turn into large plates or rocks.
In addition, the alignment of a plate usually lies over the arrangement of rocks at the top of the asthenosphere. Then, the causal factor for the formation of tectonic plate shifts is the asthenospheric and lithosphere convection currents. Then from the current it forms plates that will move at different speeds.
The movement that occurs is estimated at 2 to 15 cm per year. While the linkages between the major tectonic plates in this world can be said to have a very big role in the geological changes that exist in this world. As for examples of events that have a major influence, such as the Himalayas in the Asian area, the North African Rifr, and the San Andreas Fault in California.
Meanwhile, Indonesia itself is surrounded by 4 tectonic plates. Then, what tectonic plates surround Indonesia? Check out this review until it’s finished, Sinaumed’s.
4 Tectonic Plates in Indonesia
Indo-Australian Plate
The Indo-Australian Plate has an area of approximately 58.9 million square kilometers. Then, the Indo-Australian plate was formed from the union of the plates between the Australian plate and the Indian plate millions of years ago. Then, a few years ago or when the Eurasian plate and the Indo-Australian plate collided with each other, the Himalayas formed.
In addition, several researchers who have done research on the Indo-Australian plate believe that the Indian plate and the Australian plate are two plates that separated from each other several million years ago.
In Indonesia, the Indo-Australian plate is in the eastern region, such as the island of Papua and also the island of East Nusa Tenggara which is then interconnected with the Eurasian plate in the west and the Pacific plate in the north.
Eurasian Plate
The next plate in Indonesia is the Eurasian plate. This one plate is estimated to have an area of approximately 67.8 million square kilometers. Because this plate is quite wide, this one plate is included in the third largest plate in the world. In fact, almost all areas on the continents of Europe and Asia are on this one plate.
In addition, there have been many geological schemes that have occurred on the Eurasian plate. In fact, several geological schemes that occur are quite large, one of which is the formation of the Himalayas and also the formation of the Caspian Sea Lake. The lake is the largest lake in the world.
Until now, the Eurasian plate is arguably the most geologically active plate. Therefore, in the area passed by this plate, volcanic events will usually occur until earthquakes occur.
In Indonesia, the areas traversed by this plate are large islands, such as the island of Sumatra, Java, Sulawesi, and Kalimantan. Therefore, it can be said that the Eurasian plate is the basis of Indonesia today.
Pacific Plate
The third plate that surrounds Indonesia next is the Pacific plate. This Pacific plate is estimated to have an area of approximately 103.3 million square kilometers. Therefore, this plate is the largest plate in the world. In addition, the location of this plate is under the Pacific Ocean which starts from the northern part of the island of New Guinea, Indonesia.
In general, the Pacific plate can be regarded as the crust of the Ocean except in the area around California and New Zealand. In fact, this one plate played a significant role in the formation of the Hawaiian Islands.
At first, the Hawaiian Islands were volcanoes under the sea, then they were pushed up to form land that existed millions of years ago. Then, the formation of this volcano occurred through several points on the Pacific plate. Then, each of the outer boundaries of this Pacific plate forms a Ring of Fire at the bottom of the Pacific Ocean where the Ring of Fire causes volcanoes in some areas.
Philippine Sea Plate
The fourth plate that surrounds Indonesia next is the Philippine Sea plate. If the 3 previous plates are included in the macro category, then the Philippine Sea plate is a micro plate. This is because this one plate has an area of approximately 5.5 million square kilometers.
The Philippine Sea Plate is located in the northern region of Halmahera Island, Waigeo, Papua. In addition, it is also located in the outermost part of the Sangihe Talaud archipelago. The Philippine Sea Plate is in direct contact with 3 macro plates in Indonesia, namely the Eurasian plate, the Indo-Australian plate and the Pacific plate.
Indonesia is on the Earthquake Path of the Confluence of Three Continental Plates
In Indonesia, earthquakes often occur. In fact, there has been a lot of data which later shows that the Indonesian archipelago is often shaken by earthquakes including the July 4, 1991 earthquake in Alor, in fact this event destroyed more than 1,300 houses, and also killed 181 people, leaving around 5,400 people homeless.
Then, on December 26, 2004, Aceh in North Sumatra was rocked by a devastating earthquake with a magnitude of 8.9 which was also accompanied by a tsunami. Around 200 thousand victims are estimated to have died with around 110,146 buried, and another 127,749 were later declared missing.
Then, there was an earthquake that occurred in Yogya and Central Java on May 27 2006. In fact, the victims were estimated at 7,800 people with thousands of buildings destroyed. Then, some time ago this earthquake also hit Palu and Donggala, South Sulawesi.
The geologist who is also the graduate director of UPN Veteran Yogyakarta in a seminar at TMII Jakarta, some time ago, explained that the Indonesian archipelago is a confluence of three continental plates. These plates are the Indo-Australian Plate, the Pacific Plate, and the Eurasian Plate.
Each plate in Indonesia has a different movement, such as the Indo-Australian plate which is moving northeast at a speed of 7.7 cm/year, the Pacific plate which is moving northwest at a speed of 10.2 cm/year. year. Meanwhile, the Eurasian plate is relatively immobile.
In Indonesia itself, the movement of the collision can cause volcanoes, starting from the northern tip of Sumatra Island, to the islands of Java, Bali Island, NTT all the way to the east turning towards Maluku. Therefore, there is evidence that the impact movement is still ongoing.
This collision has made Indonesia the largest archipelagic country in the world which is very complex and at the same time unique. Therefore, we find many different forms of beaches, sea trenches, 129 active volcanoes (and 35 volcanoes on the island of Java) and faults, and finally faults, making it prone to tectonic earthquakes.
As a result of this movement, tectonic earthquakes often occur in Indonesia which can then be dangerous for human civilization. For example, the tectonic earthquake that hit Yogyakarta on May 27 2006.
“The islands of Sumatra, Java, Bali, NTT, Maluku, Papua and Sulawesi are all in the earthquake’s path. In Indonesia, only the island of Kalimantan is stable and not shaken by tectonic earthquakes or tectonic shock activity,” said Danisworo. He added, given the occurrence of earthquakes due to plate collisions in Indo-Australia and Eurasia, it is almost certain that there is a connection between one earthquake and another.
However, if the plates are different, then there is no connection between the earthquakes. The earthquakes in Aceh, Padang and Java were successive, so other areas which were traversed by the same route, namely in East Java, Bali and NTT are areas that are prone to other earthquakes. The release or occurrence of an earthquake is usually followed by aftershocks that occur in several nearby areas.
For example the earthquake in Tokyo on June 1 and July 16 1990, which was then followed by the earthquake in the Philippines. The earthquake that occurred in Yogyakarta on May 27 2006 occurred at 05.54 WIB with the epicenter 37 km southwest of the city of Yogya (on the beach). Then this earthquake was followed by an earthquake that occurred at coordinates 8.007 South Latitude and 110.286 East Longitude, with a depth of 17.1 Km below the ground surface, with a magnitude of M5.9 based on BMKG data.
This earthquake occurred as a result of fault activity or a horizontal fault that was directed southwest-northeast. This fault is also the impact of the Indo-Australian tectonic plate that collides with the Eurasian Plate. The fault then passes through Parangtritis, Imogiri, Piyungan, Prambanan, and continues northeast to Jatinom, Klaten, and to Gemolong, Sragen.
This area and a radius of several kilometers from the track area will be damaged. The damage is also influenced by morphological conditions and rock types. Then, the Bantul area is the worst affected area because besides being close to the source of the earthquake, the rock in the Bantul area usually consists of alluvial deposits, limestone and volcanic eruption deposits which tend to increase the effects of earthquake shocks.
Why didn’t the Yogya earthquake cause a tsunami?
He explained that the source of the earthquake on the coast did not have the potential to cause a tsunami. Tsunami waves themselves can occur if the earthquake strength is at least M6.5. However, this also depends on the distance, to the depth at the epicenter. After the earthquake, it was followed by a rapid decrease in the sea, and then the water seemed to be pushed back in the form of big waves. The speed of the tsunami is between 50-100 km/hour, the height of the tsunami waves varies from 3-500 meters.
Indonesia is Surrounded by 295 Active Faults
In Indonesia, there are 295 active faults and all of these active faults surround Indonesia. The active fault itself is located along the southern islands of Java, Sumatra, NTT up to the top of the Banda Sea. In addition, there were 295 faults, said the BMKG National Earthquake Study Center Coordinator for Earthquake and Tsunami Mitigation Daryono via text message.
Then, the fault moves horizontally and stretches along 1,900 kilometers from the west side of Sumatra Island. The rate or shift of this fault can reach 5 millimeters per year. Then the Mentawai fault moves up and extends in the Mentawai Islands from north to south. The movement of this fault is 14-15 millimeters per year.
Furthermore, the Palu Koro fault moves horizontally and divides the island of Sulawesi from Palu bay to the Bone valley. Then, the movement of this fault can reach 30-44 millimeters per year. Sorong Fault. A horizontal fault formed by the collision of the Indo-Australian Plate with the Pacific Plate. The movement of the Sorong fault itself is recorded at 8.5 millimeters per year.
Then, a shear fault that stretches from the Harbor to Subang. The movement of this fault itself occurs 4 millimeters per year. The Lembang Fault which is located from the Lembang rock mountain to Padalarang which, if calculated, is about 29 kilometers and its movement is 1.5 millimeters per year.
The Opak Fault is a fault that stretches from the Wonosari plateau to Yogyakarta. Its movement is 2.4 millimeters per year. Then, there is the Goat fault. the one where this fault rises through Goat Island. In addition, this fault is also suspected of raising Kambing Island to sea level. It moves 5.5 millimeters per year.
Related Books
Principles of Earthquake Resistant Architectural Design
Second, building failures due to earthquakes in general are not solely the result of the mistakes of civil contractors, but are mostly caused by design errors which mostly result from the work of architects. Third, Indonesia’s location which is surrounded by the ring of fire has required every actor in the building to understand the basic principles of earthquake safe buildings.
This book contains a discussion of how building designs should be prepared against potential earthquakes. Accompanied by clear illustrations and examples and equipped with a method for evaluating the vulnerability of buildings to earthquakes. This book can be used as a basic guideline for earthquake resistant building design in Indonesia, especially for medium and simple buildings which constitute the largest population of buildings in this country.
Geography of Natural Disasters
This book explains the direction and scope of ideological studies in media studies. Its contents provide an explanation of various thoughts that have developed regarding the relationship between the media and society and ideological factors as the background to the problems of media content.
The presence of this book is very important especially for understanding the status and position of the media in social, economic and political constellations and contestations. This book can not only be read by students from the communication science study program or also from other social science groups, but can also be read by observers and activists of media studies as well as media actors themselves.
Natural Disaster Emergency Response
This book provides brief knowledge about several natural disasters, both understanding. Types of disasters and how to deal with them. In addition, this book also provides information on PMI and SAR, which are the front guards in the event of a disaster. Regarding the introduction of first aid, I provide it to make it easier for readers to understand how to deal with disaster victims.
why? Natural disasters
The Southeast Asian region which is one of the beautiful tourism areas has turned into rubble because of the tidal waves. In addition, every year many people have been victimized by the ferocity of hurricanes, droughts and intense snowstorms. Such a force of nature is extremely terrifying. Through this book, we can learn about disasters that have occurred in the past and those that may occur in the future, and we can think together about how to deal with these terrible disasters.
Closing
Thus the discussion about plates in Indonesia . Hopefully all the discussion in this article is useful for Sinaumed’s.
If you want to find various kinds of books on geography, then you can get them at sinaumedia.com . To support Sinaumed’s in adding insight, sinaumedia always provides quality and original books so that Sinaumed’s has #MoreWithReading information .
Also read: