Is Indonesia prone to tsunamis? Tsunami Risk Identification

Indonesia is a country composed of beautiful islands. Those islands have beautiful beaches, serve delicious food, and offer many tourist attractions. However, behind this beauty, the country hides some dangers as it lies in an earthquake and tsunami zone. Is Indonesia prone to tsunamis?

Earthquakes are a daily occurrence in this country. The Meteorology, Climatology, and Geophysics Agency (BMKG) announces earthquake reports almost every day. Most of those earthquakes do not trigger tsunamis. However, it does not mean that tsunamis will not hit Indonesia.

Is Indonesia Prone to Tsunamis? Why?

Indonesia is vulnerable to tsunamis. According to a report, at least 77 tsunamis have hit this country since the 1600s. This report also stated that over 200,000 people in this country died due to this hazard. 

Moreover, scientists have predicted that some coastal areas in Indonesia are prone to massive tsunamis triggered by megathrust earthquakes. Why is Indonesia prone to tsunamis?

• Located in the Ring of Fire: This country lies in the Pacific Ring of Fire, where most earthquakes and tsunamis on Earth occur. Therefore, it is not surprising that this country is prone to tsunamis.

• Low-Lying Coasts: Many coasts in Indonesia’s tsunami zone are low-lying areas. They don't have a natural embankment to block massive waves. 

• Plate Tectonics: The Indonesian islands are on the boundary of two or three tectonic plates. They are the Indo-Australian, Eurasian, and Pacific plates. These plates may collide with each other anytime and cause destructive underwater earthquakes that lead to tsunamis.

• Underwater Volcanoes: Indonesia is home to several underwater volcanoes. They may explode and cause a large displacement of seawater. Thus, massive waves will hit nearby coastal regions.

Tsunami-Prone Areas in Indonesia 

Is Indonesia prone to tsunamis? Yes, but not all coastal regions in this country have high tsunami risks. Below are Indonesia’s coasts that are at risk of being swept by massive tsunamis.

1. The West and South Coasts of Sumatra

The west and south coasts of Sumatra border the subduction zone of the Indo-Australian and Eurasian plates. Moreover, megathrust earthquakes have hit these regions and caused tsunamis. The most phenomenal one is the 2004 Aceh Tsunami. 

Recently, scientists have released a report that another massive earthquake and tsunami have the potential to hit Sumatra’s coasts. The highest tsunami risk is in the Mentawai-Siberut segment. This area has a long tectonic gap. 

Therefore, it may release a powerful tectonic energy anytime soon. Scientists predict this earthquake will trigger a tsunami of up to 34 m tall. Moreover, this massive tsunami may only need 10 minutes to reach the Mentawai Islands and the west coast of Sumatra.

2. South Coast of Java

The south coast of Java is also at high risk of tsunamis as it is on the boundary of the Indo-Australian and Eurasian plates.. There are three tectonic segmentations on this coast, i.e., the Sunda Strait-Southern Banten, West-Central Java, and East Java segments. 

According to a report, a megathrust earthquake may hit one of those segments at a magnitude of 8.7 to 9.1SR. Moreover, it may trigger a tsunami up to 20 m tall. This wave may sweep the coast 20 minutes after the earthquake.

3. Sulawesi

Sulawesi is tsunami prone because it lies in a complex boundary of the Pacific, Eurasian, and Indo-Australian plates. Moreover, this island has several active tectonic faults. Therefore, almost all coastal regions on this island are vulnerable to tsunamis.

Many large earthquakes and tsunamis have hit this island in the past. The latest one was the 2018 Palu Earthquake and Tsunami, which killed over 4,300 people. Despite this recent occurrence, a tsunami risk remains to be anticipated.

According to a report, the north arm of Sulawesi has the highest megathrust and tsunami risks compared to other regions on the island. The maximum magnitude of this potential earthquake is 8.5SR. Therefore, it can trigger a destructive tsunami in northern Sulawesi within 10 minutes.

4. Bali, Lombok, and Maluku

Is Bali at risk of tsunami? Tsunami-prone areas in Bali are the east and south coasts. However, the East Coast has a higher tsunami risk. Together with the west coast in Lombok, eastern Bali receives tsunami threats from earthquakes on the Flores back-arc thrust. 

The Flores back-arc thrust is an active fault system under the Lombok Strait, a sea separating Bali and Lombok. Scientists forecasted an earthquake of 8.5 near Bali and Lombok. They calculated that this hazard will trigger a 26-m tsunami.

The neighboring islands of Lombok, including Maluku, are also prone to tsunamis. However, tsunamis in those islands are not always the result of earthquakes. According to a report, a potential tsunami caused by a submarine landslide is present in those islands.

5. North Coast of Papua

The north coast of Papua is extremely prone to earthquakes and tsunamis because this region is on the boundary of complex tectonic plates. Moreover, this region also has several active tectonic faults. 

The tectonic movements in Papua often result in powerful earthquakes that trigger tsunamis. Tsunami risk on the north coast of Papua may also come from submarine landslides. 

In addition, this region is also vulnerable to distant tsunamis. However, these tsunamis typically arrive at this coast more than an hour after the warning. Thus, people have time to evacuate from the danger.

Is Indonesia prone to tsunamis? Yes, it is. That’s why the government established a tsunami early warning system to reduce this disaster risk. This risk-reduction strategy will be more effective if the government adopts the best cell broadcast technology. This technology can be purchased on smsbroadcaster.com.