Crystals Can Help Predict Volcanic Eruptions
If you had a crystal ball that could predict when a volcano would erupt, it would be incredibly valuable for the millions of people who live near active volcanoes. Surprisingly, certain crystals can actually assist in forecasting volcanic eruptions. These crystals are formed in molten rock as it moves from deep within the Earth to the surface.
With advancements in scientific methods, we can extract a hidden history of volcanoes from these crystals. This historical data can provide insights into past eruptions, including the reasons behind them, where they occurred, and when they happened. By analyzing this information, we can better interpret signs of volcanic unrest, such as earthquakes that indicate the movement of magma towards the surface. In essence, we are getting closer to having our own crystal balls for predicting volcanic activity.
Magma, the extremely hot molten rock responsible for volcanic eruptions, is generated deep below the Earth’s surface in the mantle. As it rises towards the surface, magma can become trapped in various reservoirs along the way and follow a complex pathway to its eventual eruption. During this ascent, the magma cools down and forms tiny crystals that are brought to the surface during eruptions.
Once the magma reaches the surface, it can either flow and create lava or explode, producing fragmented particles known as pyroclasts. These lavas and pyroclasts eventually cool and solidify, forming volcanic rocks that contain crystals from deep within the Earth.
These crystals have survived the intense journey to the surface and the eruption itself, preserving a record of everything they witnessed inside the volcano. The appearance of the crystals varies depending on the minerals they contain. For example, Hawaiian lavas often contain green olivine crystals, while the lavas of Tweed volcano at the border between Queensland and New South Wales can have large white plagioclase crystals.
One particularly important mineral for understanding volcanoes is clinopyroxene, which forms shiny black crystals that hold valuable information. These crystals, although small in size, exhibit growth features that record events within the volcano prior to eruptions. Similar to tree rings, clinopyroxene crystals grow in concentric zones, and changes in the chemistry of these zones indicate shifts in the magma environment inside the volcano.
The outermost growth zone of the crystal is especially significant, as it reveals whether the eruption was triggered by new magma rising from deep within the Earth. By measuring the blurring of chemical changes in the crystals, we can estimate the time it takes for magma to reach the surface. This information is crucial for monitoring volcanoes and providing early warnings of potential eruptions.
Clinopyroxene crystals can also exhibit different compositions in different directions, known as sector zoning. This phenomenon indicates rapid crystal growth and suggests complex events, such as magma mixing, convection, rising, or gas release, occurred before the eruption. By observing indirect signs of these processes on the surface, we can assess the likelihood of an impending eruption.
Additionally, pinpointing the location of eruption triggers within the volcano can provide valuable insights. This information helps determine if earthquakes or deformations at specific depths are indicative of an upcoming eruption.
Analyzing the chemistry of clinopyroxene is crucial for deciphering volcano histories. This involves sophisticated laboratory techniques, such as using lasers or synchrotron light from particle accelerators, to measure chemical variations in the crystals. These micro-scale analyses allow us to uncover the secrets of magma stored beneath the surface and reconstruct the internal structure of a volcano.
So, the next time you visit a volcano, keep an eye out for colored specks in the rocks. You may be looking at crystal balls that contain the volcano’s history and provide clues about its future behavior.
