In News:

A recent scientific study has revealed renewed geological activity at Mount Taftan, a stratovolcano in southeastern Iran, raising concerns among volcanologists and regional authorities. The volcano, believed to have remained inactive for nearly 700,000 years, has exhibited ground uplift and increased gas emissions, suggesting possible magmatic or hydrothermal movement beneath the surface.

Key Findings from Recent Study

• Research published in Geophysical Research Letters notes that ground near Taftan’s summit rose by ~9 cm between July 2023 and May 2024.
• Persistent uplift signals buildup of gas pressure below the volcano.
• Residents reported strong sulfurous fumes, detectable up to 50 km away in the city of Khash.
• Satellite monitoring (ESA’s Sentinel-1) indicated activity in absence of ground-based GPS stations.

Scientists stress there is no immediate eruption threat, but the volcano should be reclassified from "extinct" to dormant and monitored more closely due to increasing activity.

About Taftan Volcano

• Location: Southeastern Iran, ~56 km from Pakistan border
• Elevation:3,940 m (12,927 ft)
• Type: Semi-active stratovolcano (composite volcano)
• Volcanic Arc: Only active volcano in the Makran subduction zone
• Geological Setting: Formed due to subduction of Arabian oceanic crust beneath Eurasian plate
• Key Features: Two summits — Narkuh and Matherkuh
• Activity Indicators:
  • Active hydrothermal system
  • Sulfur-emitting vents (fumaroles)
  • No recorded eruptions in human history

What is a Stratovolcano?

• Tall, steep-sided cone-shaped volcano
• Commonly found along convergent plate boundaries
• Composed of alternating lava flows and pyroclastic deposits
• Eruptions tend to be explosive due to viscous magma (andesite/dacite)
• Examples: Mt. Fuji, Mt. St. Helens, Vesuvius, Krakatoa

Why is it in the News?

For the first time, astronomers have observed the area right at the edge of a black hole where matter stops orbiting and plunges straight in at near-light speed.

What is the Plunging Region of a Black Hole?

• The plunging region of a black hole is an area where matter ceases to orbit the celestial object and instead falls directly into its incalculable depths.
  • This phenomenon was initially predicted by Albert Einstein's groundbreaking theory of general relativity, which continues to shape our understanding of the cosmos.
• As matter approaches a black hole, it is torn apart and forms a rotating ring known as an accretion disc.
• According to general relativity, there exists an inner boundary within this disc, beyond which nothing can maintain its orbit around the black hole.
  • Instead, the material is drawn towards the black hole at nearly the speed of light, marking the beginning of the plunging region.
• This region, situated just outside the event horizon, represents the point of no return for matter falling into a black hole.
• Despite the challenges posed by studying these enigmatic structures, researchers believe that investigating plunging regions could unveil new insights into the formation and evolution of black holes.
• Additionally, these studies may offer valuable information about the fundamental properties of space-time, potentially transforming our understanding of the universe and its most mysterious inhabitants.

What is a Black Hole?

• A black hole is a celestial phenomenon that arises from the remnants of a massive star that has exhausted its nuclear fuel and undergone gravitational collapse.
• It is characterized by an unfathomably dense core, known as a singularity, which is enveloped by a boundary called the event horizon.
• The event horizon serves as a point of no return; any matter or light that crosses this boundary is irrevocably drawn towards the singularity, making it impossible to escape the immense gravitational pull.

Black holes are classified into three categories based on their size and formation process:

• Stellar-mass black holes: These form when a massive star collapses at the end of its life cycle. They typically have masses ranging from approximately five to several dozen times that of our Sun.
• Supermassive black holes: Found at the centre of most galaxies, including our own Milky Way, these colossal structures boast masses that can reach billions of times the mass of the Sun.
• Intermediate-mass black holes: With masses between those of stellar mass and supermassive black holes, these entities are thought to form through the merger of smaller black holes or the collapse of dense clusters of stars.
• Due to their extreme nature, black holes have been the subject of extensive research and fascination in the scientific community.
• The study of these enigmatic structures continues to yield invaluable insights into the fundamental principles governing our universe.