Sunda Strait

The Sunda Strait is a thin channel between the Indonesian islands of Java and Sumatra. The strait connects the Java Sea and the Indian Ocean. Although narrow and shallow in areas, the Sunda Strait provides a valuable shortcut for small ships conducting travel and trade missions. The area is most famous for eruptions of the Krakatoa volcano, mainly in 1883, and battles fought in the strait in 1942 by Japanese and Allied forces.

Background

The Sunda Strait is a narrow water channel between Java and Sumatra, two major islands of Indonesia. A strait typically connects two large bodies of water; in this case, the Sunda Strait connects the Indian Ocean (to the southwest) and the Java Sea (to the northeast). The strait runs approximately from the northeast to the southwest. At its narrowest point, near Cape Pujat and Cape Tua, it is about 15 miles (24 kilometers) wide. In this narrow area, the strait is also at its shallowest; in some areas, the water is only about 66 feet (20 meters) deep.

Although most of the western area of the strait is deeper, the shallows make it traditionally quite challenging to pass through. Adding to this challenge are natural obstacles such as sandbanks, powerful tides, and industrial outposts, including Javanese oil rigs. Very large vessels may avoid the Sunda Strait altogether and opt instead for the Strait of Malacca, located north of Sunda between the Malaysian Peninsula and the northern coast of Sumatra.

The Sunda Strait is part of the so-called Ring of Fire, a region of the Pacific Ocean that experiences frequent volcanic and seismic activity. This activity is due to plate tectonics, the gradual motion and frequent collisions of huge masses of crust under the planet's surface. Several islands in the Sunda Strait are home to volcanoes, most notably Krakatoa. Other volcanic islands are Panaitan, Sangiang, Sebesi, and Sebuku.

The name Sunda Strait derives from groups of people in nearby Java, the island to the southeast. It alludes partially to the Indigenous Sundanese people of western Java, and partially to the Sunda Kingdom, a power in the same region.

Overview

People have lived in the Sunda Strait region and the surrounding islands since ancient times. The Sunda Strait first came to international significance around the seventeenth and eighteenth centuries, when traders from the Dutch East India Company passed through it on journeys to Indonesia to gather valuable spices.

One of the most noteworthy—and tragic—events in the Sunda Strait’s history occurred in 1883. Starting in May of that year, the volcano on the island of Krakatoa began to erupt. The violent natural disaster started with earthquakes and the emission of steam from the volcano. These ominous activities lasted for months. The peak of the catastrophe occurred on August 27, 1883, when a series of violent eruptions destroyed most of the island. Much of the land collapsed into a vast crater.

The cataclysmic blast created a large tsunami, a series of extremely powerful waves triggered by a huge displacement of water. The waves of the tsunami towered some 125 feet (38 meters) high and killed more than 36,000 people and destroyed more than 300 villages and towns in the area. Even after this disaster, the volcano continued with lesser eruptions for about two more months, finally settling down in October.

Altogether, the Krakatoa eruption of 1883 entered history as one of the worst volcanic eruptions of all time, both in level of destruction and in loss of human lives. However, it was only the first landmark event in the modern story of Krakatoa’s devastation. Other eruptions have caused destruction and suffering in the region. Notably, a volcano known as Anak Krakatau, or “Son of Krakatoa,” erupted on December 22, 2018.

The 2018 eruption sent 160 acres of rock, ash, and other projectiles onto nearby land and water. The amount of material ejected from the volcano reduced its height from about 1,109 feet (338 meters) to just 361 feet (110 meters) in a brief time. Much of the debris struck the water and the sudden and violent displacement led to a tsunami. Although this tsunami was only a fraction of the size of the 1883 disaster—this one creating waves up to 21 feet (6.6 meters)—it still created destruction and chaos in nearby communities. Serious damage occurred on both Java Island and Sumatra Island.

International aid organizations rushed to help the islanders recover. However, the sudden and violent event highlighted a fundamental flaw in disaster preparation. Existing systems in Indonesia and other areas can issue accurate and timely warnings of likely tsunamis, but only tsunamis caused by earthquakes. Both Krakatoa tsunamis involved eruptions and displacement of water by collapsing landforms, which happens too quickly to allow forewarning. For this reason, such tsunamis may be the most dangerous of all.

Another major chapter in Sunda Strait history occurred during World War II (1939–1945). During this conflict, much of the Pacific Ocean was being contested between the Allied forces and the Japanese, members of the Axis alliance. In February 1942, Japanese ships sailed toward Java with plans to invade the island, which was then controlled by the Allies. They were intercepted on the way on February 27 by a group of fourteen Allied ships. The Japanese ships battered the Allies, sinking six ships and forcing the rest to withdraw. Two of the main Allied ships, the American USS Houston and Australian HMAS Perth, returned to Sunda Strait that night and re-engaged Japanese forces. After a bitter hour-long battle, both Allied ships had been sunk at significant loss of life. Meanwhile, five Japanese ships sank, though three were casualties of friendly fire.

On March 4, another engagement took place in Sunda Strait, this time pitting the Australian HMAS Yarra and three other ships against a force of five Japanese cruisers and destroyers. Again, the Japanese forces triumphed, sending all four Allied ships to the bottom.

In December 2018, a devastating tsunami occurred in the Sunda Strait following a massive underwater landslide caused by the eruption of Anak Krakatau. Indonesia’s tsunami warning system was designed for earthquake-related tsunamis, so there were no warnings for island residents and tourists. Over 400 people died, and thousands of homes and businesses were destroyed, particularly in Pandeglang, South Lampung, and Serang. The government improved its tsunami detection system following the disaster. In 2019, a 6.9 magnitude earthquake occurred near Sumur in Banten. Though a tsunami warning was issued, no significant damage was reported.

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