Growth and thermal maturation of the Toba magma reservoir
Ping‐Ping Liu, Luca Caricchi, Sun‐Lin Chung, Xian‐Hua Li, Qiuli Li, Mei‐Fu Zhou, Yu‐Ming Lai, Azman A. Ghani, Theodora Sihotang, Tom Sheldrake, Guy Simpson
Abstract
Significance Understanding the thermal state of magma reservoirs before supereruptions is crucial for interpreting the processes leading to such catastrophic events. Here, we show that the two supereruptions of Toba were preceded and followed by protracted magma influx at relatively constant average volumetric rate over the past 2.2 My. This suggests that increased magma flux is not essential before supereruptions. Instead, long-term thermal maturation of the magma reservoir related to significant magma pulses primes the system for eruption. Importantly, our results indicate that significant variations of monitoring parameters, such as increased surface deformation or degassing, may not occur before supereruptions. Our method can be widely applied to other large silicic magmatic systems to evaluate their potential to feed a supereruption.