Where is the Krakatoa Volcano Located?

Historically, Krakatoa was a modest volcanic island situated in the Sunda Strait, lying between Java and Sumatra. Today, the name is associated with an archipelago of four islands in Indonesia. Varlaten and Lang are remnants from previous eruptions, while Rakata was formed during the catastrophic event of 1883, which obliterated two-thirds of the original island. The most recent addition, Anuk Krakatoa, emerged from beneath the ocean surface less than a century ago.

History of the Krakatoa Eruption in 1883

During the 19th century, Krakatoa was devoid of human habitation. The island's intense volcanic and seismic activities created an inhospitable environment for life. The tallest cone stood at 813 meters, rendering it an uninviting locale for settlers. Increased seismic activity was first noted in 1878, and two years later, a significant earthquake devastated much of the western Java coastline. In May 1883, the region experienced further intense tremors, leading to the largest crater on Krakatoa venting ash and gases. This was followed by the formation of cracks in the slopes, allowing seawater to infiltrate. For three months, the island was engulfed in steam clouds, signaling an impending disaster.

On August 26, 1883, at 12:53 PM local time, a series of violent explosions erupted. A smoke column ascended approximately 27 kilometers into the sky, and the thunderous noise was detectable as far away as 4,300 kilometers. Hours later, a tsunami struck nearby shores. The following day, four additional explosions occurred, with the final one recorded at 10:02 AM local time. This event marked one of history's most significant natural disasters. Enormous volumes of volcanic ash were propelled into the atmosphere, with estimates ranging from 19 to 40 cubic kilometers. This ash likely reached the mesosphere, with flashes visible on islands thousands of kilometers away in the Indian Ocean. A powerful shockwave encircled the globe three and a half times at speeds of 1,100 km/h.

Consequences of the Krakatoa Volcano Eruption

The explosive eruptions obliterated much of the island. Rakata, the remnant of the disaster, now comprises only one-third of its original size. For an extended period, the island remained desolate, devoid of life. Pyroclastic flows triggered catastrophic tsunamis that reached heights of 40 meters and traveled at speeds exceeding 700 km/h, devastating coastal settlements. The waves encircled half the planet before dissipating.

Volcanic ash blanketed 70% of the Earth's surface, contributing to significant climatic anomalies. Sunlight was insufficient, leading to a global temperature drop of about 1.2 degrees Celsius. Unusual weather patterns ensued, with intense summer rains and warmer winter temperatures. Normal weather conditions returned only after five years. The dust accumulation also led to unprecedented phenomena; for example, the Sun appeared greenish in the northern hemisphere for 36 months, and the Moon exhibited a bluish hue. Auroras were observed at lower latitudes in Europe.

The catastrophic eruption resulted in the deaths of an estimated 36,000 to 40,000 individuals.

Krakatoa Eruptions in Later Years

In 1927, a new island emerged, named Anak Krakatau, translating to "Child of Krakatoa." This formation is merely the cone of an underwater volcano. Though eruptions are frequent, most have not posed significant danger. However, the active nature of this volcano remains a serious concern, as highlighted by the events of December 22, 2018. Although the eruption itself was moderate and caused limited damage to the Java and Sumatra coasts, it triggered a 5-meter tsunami that resulted in 370 fatalities and 15,000 injuries. The most recent eruption occurred in October 2021, producing ash that rose to 1.5 kilometers without generating a tsunami.

Can Krakatoa Volcano Be Visited?

Despite its ongoing activity and annual growth of approximately 7 meters, Anak Krakatau is accessible to tourists. However, visits depend on current volcanic activity. At times, the cone can only be viewed from a distance by boat, but under favorable conditions, visitors can explore the island and even ascend its slopes. Before the 2018 eruption, the volcano reached 400 meters; post-eruption, its height reduced to 110 meters.

Explore how the Krakatoa eruption reshaped history and geography, as depicted in this detailed documentary.

Discover the devastating effects of the Krakatoa explosion and the implications for the Earth’s geological processes in this comprehensive episode.