Krakatau eruption and tsunami, Indonesia (August 26-27, 1883)

Figure 1. An 1888 lithograph of the eruption of Krakatau. Source: mentalfloss.com

  
 The volcano Krakatau is located on the island of Rakata, which is part of the Indonesian Island Arc and is located in the Sunda Strain between Java and Sumatra (Augustyn). Starting on August 26th and ending in August 27th of 1883, Krakatau erupted, sending nearly five cubic miles of rock fragments into the air and causing a series of tsunamis that were recorded as far away as South America and Hawaii (Augustyn). The eruption, assigned a rating of six on the Volcanic Explosion Index, released an estimated eleven cubic miles of debris into the atmosphere that darkened the skies within 275 miles of the volcano for three days (Bagley). More than 36,000 people were killed as a result of the eruption, with around 5,000 deaths coming from the initial eruption (History.com Editors). This eruption sent out pyroclastic flows containing a high-density mix of hot lava blocks, pumice, and volcanic ash (NCEI) that stretched across the sea as far as forty miles, scorching everyone in its path (History.com Editors). Though the initial eruption had many casualties, it does not begin to stand up to the severity of the ensuing tsunamis. After the eruption, much of the island of Rakata fell into the water (Figure 2) (Bagley). This event created waves as big as 120 feet tall that washed over nearby islands, stripping their vegetation and carrying many people out to sea (Bagley). These tsunamis destroyed 165 coastal villages in the surrounding areas and killed around 31,000 people (Bagley).

Figure 2. Island of Rakata before and after eruption. Source: researchgate.net

    Krakatau had major implications on the global climate in the years following the eruption. In 1884, the average global summer temperatures fell by around 2 degrees Fahrenheit (Figure 3) (Williams). Even five years after the eruption the average global temperature was still 1.2 degrees Fahrenheit below normal (Bagley). In addition, some regions experienced unusual weather. For example, areas in California recorded record amounts of rainfall between July 1st, 1883 and June 30th, 1884 (Williams). During this period, Los Angeles received 38.18 inches of rainfall which remains the wettest year on record for the city (Williams). 

Figure 3. Global temperature changes 1880-1890. Source: arcgis.com

    Mitigation efforts were limited at the time because not much was known about volcanic eruptions. Warning signs were showing months before Krakatau erupted. In May of 1883, the captain of a German warship reported seeing clouds of ash above the volcano (Bagley). Over the next few months leading up to the eruption, sightseeing boats travelled near the volcano and reported thundering noises and incandescent clouds (Bagley). These signs of an impending eruption could have allowed citizens in surrounding areas to evacuate if they were in close proximity to the actual volcano, or at least be prepared to travel to higher elevations as far inland as possible to protect from the threat of tsunamis. 

This video talks about various points that I have mentioned in this blog. It discusses general information about Krakatau, early signs that an eruption was pending, the power of the eruption, and the global climate effects the eruption caused.

Works Cited

Augustyn, Adam. "Krakatoa." Britannica, 16 January, 2020, https://www.britannica.com/place/Krakatoa.

Bagley, Mary. "Krakatoa Volcano: Facts About the 1883 Eruption." LiveScience, 15 September,

        2017, https://www.livescience.com/28186-krakatoa.html#:~:text=The%20eruption%20of

        %20Krakatoa%2C%20or,more%20than%2036%2C000%20people%20died.&text=In%20M

        ay%201883%2C%20the%20captain,clouds%20of%20ash%20above%20Krakatau.

History.com Editors. "Krakatoa Explodes." History, 25 August, 2020, https://www.history.com/this-

        day-in-history/krakatau-explodes.

“On This Day: Historic Krakatau Eruption of 1883.” National Centers for Environmental Information 

        (NCEI), 23 August, 2018. https://www.ncei.noaa.gov/news/day-historic-krakatau-eruption-1883. 

Williams, Jack. "The Epic Volcano Eruption That Led to the 'Year Without a Summer.'" The Washington Post, 10 June, 

        2016, https://www.washingtonpost.com/news/capital-weather-gang/wp/2015/04/24/the-epic-volcano-eruption-that

        -led-to-the-year-without-a-summer/.