VOLCANIC VORTEX RINGS

In recent days, Mount Etna, Europe's largest volcano and one of the world's most active and iconic volcanic peaks, has been emitting nearly perfect rings of smoke into the atmosphere. These rings, known as volcanic vortex rings, are a rare phenomenon that scientists liken to the smoke rings created by some cigarette smokers.

Volcanic vortex rings occur when certain conditions align during volcanic activity, leading to the formation of circular smoke patterns resembling rings. Mount Etna's recent display of this phenomenon is noteworthy due to the rarity of such occurrences and the volcano's reputation for unique and dynamic volcanic activity.

2. About Mount Etna

Situated on the eastern coast of Sicily, the largest island in the Mediterranean Sea, Mount Etna, or simply Etna, stands as one of Italy's most prominent natural landmarks. Its towering peak marks the highest point in Italy south of the Alps, earning it the distinction of being Europe's largest and one of its most active volcanoes.

Geological Features and Activity

• At its summit, Mount Etna boasts five craters, which are the primary sources of its volcanic eruptions. Additionally, over 300 vents of varying sizes pepper the slopes of the mountain, contributing to its frequent activity. Since the year 1600, Mount Etna has experienced approximately 60 flank eruptions, along with numerous summit eruptions.
• The volcano's eruptive history spans back hundreds of thousands of years, with UNESCO tracing its origins over 500,000 years ago. Documented records of its activity extend at least 2,700 years, highlighting its enduring presence and significance in geological and cultural contexts.
• In recent decades, Mount Etna has maintained a near-constant state of activity, with notable eruptions occurring in 2006, 2007-08, 2012 (twice), 2018, and 2021 at its summit. Flank eruptions have also occurred in 2001, 2002-03, 2004-05, and 2008-09. Recognizing its geological importance and cultural value, Mount Etna was designated as a UNESCO World Heritage Site in 2013.

• Volcanic vortex rings are mesmerizing natural phenomena that occur during volcanic activity when gas, predominantly water vapour, is rapidly released through a vent in the crater of a volcano. The unique circular shape of these rings is a result of the nearly perfect circularity of the vent from which they emerge.
• The earliest recorded observations of volcanic vortex rings date back to 1724 when they were first noted at Mount Etna and Vesuvius in Italy. These observations were further documented in an engraved plate from 1755, highlighting the long-standing presence of this phenomenon in volcanic activity.
• While volcanic vortex rings were initially observed at Etna and Vesuvius, they have since been documented at numerous volcanoes worldwide. Recent observations include occurrences at Redoubt in Alaska, Tungurahua in Ecuador, Pacaya in Guatemala, Eyjafjallajökull and Hekla in Iceland, Stromboli in Italy, Aso and Sakurajima in Japan, Yasur in Vanuatu, Whakaari in New Zealand, and Momotombo in Nicaragua.
• Similar to how dolphins create bubble rings underwater, volcanic vortex rings are formed when gas is expelled from the vent with enough force to create a circular pattern. These rings can linger in the air for up to 10 minutes under stable atmospheric conditions. However, they are susceptible to disintegration in windy or turbulent conditions.
• The study of volcanic vortex rings offers valuable insights into the dynamics of volcanic activity and contributes to our understanding of natural processes occurring within volcanic systems.

Mount Etna has garnered renown for its remarkable ability to generate volcanic vortex rings, making it a focal point for scientific observation and study of this captivating phenomenon.

• A "dozens of gas rings every day" above Mount Etna in volcanic activity, asserted that "no volcano on Earth produces as many vapour rings as Etna," emphasizing the prolific nature of this occurrence.
• The rings are produced by the explosive release of gas bubbles within a narrow conduit, propelling the gas at high velocity towards the surface. As the gas travels along the conduit, friction against the walls slows its movement, resulting in the formation of the characteristic vortex rings.
• Contrary to common belief, volcanic vortex rings are not as rare as often perceived, with Mount Etna standing out as a particularly prolific producer of these phenomena. The significance of Etna in the consistent generation of volcanic vortex rings.
• In April 2024, a notable increase in volcanic activity, with a small vent opening on the northeastern edge of the Southeast Crater of Mount Etna. This vent began producing a substantial number of steam rings, with estimated hundreds, if not thousands, of rings being emitted since the phenomenon began.
• Mount Etna's extraordinary capacity to produce volcanic vortex rings continues to intrigue scientists and enthusiasts alike, offering valuable insights into the dynamic processes occurring within this iconic volcanic system.

Speculation regarding Mount Etna's recent activity and the possibility of an imminent spectacular eruption has been addressed by experts, dispelling notions of an impending major event.

• In response to inquiries about the significance of the recent activity, volcanologists provided clarification, emphasizing that the current activity does not indicate an imminent spectacular eruption. The activity from the new vent was observed to be slowing down, indicating a decrease in intensity.
• The cessation of activity can occur due to various factors, such as changes in the properties of the conduit. Potential obstructions within the conduit may alter its dynamics, affecting the conditions necessary for the formation of volcanic vortex rings.
• Addressing concerns about the interpretation of recent activity, experts aim to manage expectations and provide accurate assessments of volcanic phenomena. While the occurrence of volcanic vortex rings may capture attention, it does not necessarily signify imminent volcanic eruptions of significant magnitude.
• As Mount Etna's activity evolves, ongoing monitoring by experts remains crucial in assessing any potential changes and understanding the underlying processes driving volcanic phenomena. Through careful observation and analysis, scientists aim to provide reliable insights into the behaviour of this dynamic volcanic system.