The Mystery of the Flying Volcanic Ash Particles Revealed
When the Eyjafjallajokull volcano erupted in Iceland in April 2010, air traffic was interrupted for six days and then disrupted until May. Interestingly, particles of the volcano were discovered in UK which were much larger than expected. According to Eduardo Rossi, a researcher at the Department of Earth Sciences of University of Geneva (UNIGE) said that fragments thrown out during a volcanic explosion range from a few microns to more than two metres. The larger particles are faster and closer to the volcano.
The scientists analysed the volcanic ash particles from Sakurajima volcano of Japan that erupts 2-3 times daily for more than 50 years. The scientists used adhesive paper to collect the ash before it hit the ground. IN Ehyjafjallajokull eruption, micrometric particles group into clusters. On hitting the ground it gets destroyed.
In Japan, the scientists used high speed camera to observe the sedimentation of the ash in real-time and saw the clusters. It is formed by large particle of 100-800 microns-the core-which is covered by many small particles less than 60 microns. This external layer of small particles can act like a parachute over the core, delaying its sedimentation. This is called the rafting effect. Scientists were thus able to solve the mystery of how large particles of volcanic ash particles of Eyjafjallajokull was discovered in UK which was attributed to the rafting effect.