Mains Paper 3: Environment | Conservation, environmental pollution and degradation, environmental impact assessment
From UPSC perspective, the following things are important:
Prelims level: Op Samudra Maitri, Causes of the Tsunami
Mains level: India’s HADR operations.
Operation Samudra Maitri
- India has launched a massive operation for humanitarian assistance to provide assistance to the earthquake and tsunami victims in Indonesia.
- It dispatched two aircraft and three naval ships carrying relief material to the country.
- The C-130J aircraft is carrying a medical team along with tents and equipments to set up a field hospital.
- The C-17 aircraft is carrying medicines, generators, tents and water to provide immediate assistance.
- Three Indian Navy ships — INS Tir, INS Sujatha and INS Shardul — have also been mobilised to carry out humanitarian assistance and disaster relief (HADR).
What Caused Indonesia Tsunami?
- A chain of geological events set off by the violent quake liquefied the loose soil and possibly caused an underwater landslide, triggering a tsunami wave that may have been intensified by the shape of the bay.
- The quake was likely caused by movement of the Palu-Koro fault which runs almost north to south down Sulawesi on a line through Palu’s narrow bay.
- The Palu-Koro is a strike-slip fault, where the two sides slide past each other horizontally, unlike a thrust fault which pushes one side over the other.
- A thrust quake is more likely to trigger a tsunami because its vertical motion pushes a column of seawater upwards, setting a wave in motion.
- The fault usually shifts by 30 to 40 mm a year, with the western side heading south while the eastern edge moves north.
- The shaky nature of this particular quake has triggered the liquefaction, by agitating the water to such an extent that mud bubbled up from underground, weakening foundations, and uprooting trees.