OREGON STATE UNIVERSITY

Rinjani: A Key to a 13th Century Mystery?

Rinjani volcano; it's everywhere in the news now because of its current ongoing eruption. Located on the island of Lombok, Indonesia, the ash plume formed has drifted over the Lombok airport and in the direction of Bali (a popular tourist destination) and over Bali's International Airport.

 

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Figure above: NASA satellite photo showing the ash plume from Rinjani travelling across Lombok and Bali on the 3rd of November. (Image from NASA)

 

As a result of the direction of the ash plume, flights across Lombok and Bali have been grounded, resulting in tourists being stranded for the past few days while waiting for flights to resume. As we have looked at previously as in the case of Mt Galunggung (also in Indonesia), airplanes flying through ash clouds created in volcanic eruptions face the danger of their engines stalling and potentially crashing the plane. Authorities in Indonesia have taken the safer route of avoiding this potential disaster by keeping their planes, both domestic and international, on the ground for now.

 

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Figure above: The current eruption at Rinjani (Image by LALU EDI/ANTARA FOTO/REUTERS)

 

The last eruption at Rinjani was in 2010, where the eruption was not as impactful as this one, with the ash cloud only reaching 5.5km in altitude and quickly dissipating over time. The video below is a close up of that 2010 eruption. Other hazards faced at Rinjani include lahar flows, which are mudflows of deposited ash and volcanic material that are reactivated in the presence of heavy rainfall, as what happened in 1994.

 

Video above: Eruption at Rinjani in 2010

 

What is not well known in the media is the special role Rinjani plays in climate change, especially in the past. Rinjani itself is a volcano inside a large caldera. This caldera forming eruption is believed to have been around the 13th century, and it was so explosive that material and gas ejected into the atmosphere could have potentially affected the climate. 

The mystery first started when scientists noticed spikes in sulphur content in ice records and signs that there was a large volcanic eruption around the mid 13th century, corroborating evidence from tree rings and written records from the past. Looking at modelled sulphur records, distribution of tephra, stratigraphic records, and pumice shard geochemistry, the origin of the eruption was traced back to the caldera forming eruption of 1257 A.D., in the Rinjani Volcanic Complex.

Finally, a mystery that had puzzled climatologists, volcanologists, and glaciologists was solved! With better analytical tools and more sensitive equipment, scientists have managed to distinguish a volcanic complex responsible for climate change signals seen in ice cores over 8200km away! Not only did they have to solve for the distance, they had to rule out other potential contenders, such as eruptions at Okataina or El Chichón. Isn't it cool how science can solve a mystery that is over 700 years old?

 

 

Check out the video above to see the current eruption at Rinjani and its effects on the stranded tourists.

 

 

For more information on the mystery that was solved, click here.

For more information on Rinjani, click here.