(Indonesia) Mount Kerinci in West Sumatra, Mount Semeru in East Java and Mount Merapi in the Central Java mountain range  demonstrated increased activity on Friday reports the Jakarta Post. That was the same day that the Anak Krakatau volcano erupted.

And although all of the four volcanoes are located in the same region, their activity was unrelated. That’s because each volcano boasted a different magma chamber, reports the Volcanology and Geological Hazard Mitigation Center (PVMBG).

Volcanic and tectonic activity is common in Indonesia as the southeast Asian country is situated on the Pacific Ring of Fire, a region where many volcanoes and earthquakes are formed.

“Volcanic eruptions in Indonesia are a common thing as they happen every day,” PVMBG director Kasbani. He added that the eruptions didn’t occur simultaneously.

Anak Krakatau, a volcano that erupted from the remnants of the largest volcanic explosion recorded by the Krakatau volcano in 1883, erupted twice on Friday. During the second eruption, that volcano spewed out a 500-meter-high column of ash . The eruption lasted over a half hour.