The Enigma of Silent Eruptions
Alaska’s active, ice-clad volcanoes pose a unique challenge for scientists: predicting “stealthy” eruptions that offer little to no warning. Unlike typical volcanic activity, which often precedes an eruption with ground swelling and earthquakes, some Alaskan peaks like Veniaminof can erupt without these tell-tale signs, making them particularly hazardous for air traffic and remote communities.
Uncovering Veniaminof’s Secrets
Recent research, particularly on the Veniaminof volcano, is bringing scientists closer to understanding these elusive events. A study published in Frontiers in Earth Science by scientists at the Alaska Volcano Observatory (AVO) investigated why Veniaminof’s 2018 eruption occurred with minimal forewarning.
Their findings point to a combination of factors:
- Slow Magma Flow and Small Magma Chamber: Stealthy eruptions are more likely when magma flows slowly into a relatively small chamber. This contrasts with scenarios where significant magma flow into a large chamber typically causes noticeable ground deformation.
- Warm Host Rock: If magma has consistently been present, keeping the surrounding rock of the magma chamber warm, the rock is less likely to crack or shift in ways that produce detectable earthquakes or ground deformation when new magma flows in. This effectively “masks” the warning signs.
Essentially, “stealthy” eruptions occur when specific conditions of magma flow, chamber size, and surrounding rock temperature align, preventing the usual precursors.
Towards Better Prediction
This crucial understanding is vital for improving eruption forecasting. Scientists are advocating for enhanced monitoring strategies, including high-precision instruments like borehole tiltmeters, fiber optic sensing, infrasound monitoring, and machine learning to detect subtle patterns in volcanic behavior. By integrating these advanced technologies, researchers aim to develop a more robust warning system for these unpredictable volcanoes, ultimately mitigating risks to nearby populations and aviation.
