The 1883 eruption of Krakatoa in the Sunda Strait occurred from May 20 until October 21 1883, entering its climactic phase on this day, and peaking in the late morning hours of August 27 when over 70% of the island of Krakatoa and its surrounding archipelago were destroyed as it collapsed into a caldera.

In the years before the 1883 eruption, seismic activity around the Krakatoa volcano was intense, with earthquakes felt as far away as North Australia, one of which, in 1880, damaged a lighthouse. Strombolian activity began on May 20, 1883, and steam venting began to occur regularly from Perboewatan, the northernmost of the island’s three cones. Eruptions of ash reached an estimated altitude of 6 km (20,000 ft), and explosions could be heard in Batavia (Jakarta) 160 km (100 mi) away, rattling windows and doors. Dust fell 300 miles away. An excursion party sent to the island on May 26 reported that the islands were covered with a fine white dust, with explosions coming from Perboewatan every 5 to 10 minutes. Although by this time the eruptions were calming down, some of the explosions were still very energetic, hurling pumice opposite the direction of the wind. A large crater about 3,000 feet (900 metres) in diameter formed, with a cavity from which issued plumes of steam. The eruptions soon quietened after the initial violence.

Around June 16, there were loud explosions and a thick black cloud covered the islands for five days. The eruptions started gaining strength again on June 19. On June 24, a prevailing east wind cleared the cloud, and two ash columns could be seen issuing from Krakatoa. It was also noticed that the summit cone of Perboewatan was gone, which an extensive report of a few years later attributes it to having been blown away. The seat of the eruption is believed to have been a new vent or vents that formed on that day, between Perboewatan and Danan. The violence of the ongoing eruptions caused tides in the vicinity to be unusually high, and ships at anchor had to be moored with chains. Earthquakes were felt at Anyer, Banten, and ships began to report large pumice masses to the west in the Indian Ocean. A third vent, and later many more, appeared. The eruptions continued throughout July, and their violence continued to increase until the explosions of August 27.

Krakatoa eruptions intensified on August 25 and by 2:00 p.m. on August 26, a black ash cloud could be seen 27 km (17 mi) high. At this point, the eruption was almost continuous, and explosions could be heard every ten minutes. By 5:00 p.m., the explosions were audible all over Java. Waves a few feet in height began battering the coasts of Java and Sumatra at 5:30 p.m., and continued throughout the night, which may have been produced by steam explosions.  Ships within 20 km (12 mi) of the volcano reported heavy ash fall, with pieces of hot pumice up to 10 cm (4 in) in diameter landing on their decks. Between 7:00 p.m. and 8:00 p.m., a small tsunami hit the shores of Java and Sumatra, 40 km (25 mi) away.

The eruption was one of the deadliest and most destructive volcanic events in recorded history. The explosion was heard 3,110 kilometres (1,930 mi) away in Perth, Western Australia, and Rodrigues near Mauritius, 4,800 kilometres (3,000 mi) away The acoustic pressure wave circled the globe more than three times.  At least 36,417 deaths are attributed to the eruption and the tsunamis it created.

Significant additional effects were felt worldwide in the days and weeks after the volcano’s eruption. Additional seismic activity was reported until February 1884, but any reports after October 1883 were dismissed by Rogier Verbeek‘s subsequent investigation into the eruption.

-Wikipedia