Photograph by Jonathan Aitchison "Lhotse and Everest"

Collision tectonics

Collision zones is the most fundamental tectonic process for land and mountain building. It was this collision of the India subcontinent into Asia (~34 Ma) that created the Himalaya-Tibetan orogenic system. Continental collision is a variation on the fundamental process of subduction, whereby the subduction zone is destroyed, mountains produced, and two continents sutured together. These suture zones host many ophiolite occurrences. Ophiolites represent remnants of oceanic material and their presence on-land is an indication of an ocean closure.

Subduction initiation

Plate tectonic theory provides the fundamental framework for the dynamics of Earth’s outer shells with mantle-driven lithospheric convection being a defining characteristic of our planet. The existence of tectonic plates and three types of boundary (divergent, transform and convergent) is well accepted. Incredibly, how subduction at convergent boundaries begins remains uncertain. This is the process whereby the material forming oceanic lithosphere is recycled back into the mantle and is a crucial element of plate tectonics. Subduction initiation is a transient event and systems that develop, whether geologically long-lived (>200 m.y.) or ephemeral, eventually disappear. Importantly, strong links exist between early phases of subduction and the formation of distinctive rock successions (ophiolites) suggesting a related genesis.

Tectonic disaster resilience after earthquake

Earthquakes can be devastating disasters which are neither controllable nor predictable. Thus, they have a great potential to trigger catastrophic losses and long-term interruptions to victim’s lives. From an earthquake, it is the survivors who suffer most because although they remain alive, in many cases, they have lost their previous living circumstances. After earthquakes, they need food to eat, need place to live in, need jobs to making living. Therefore, their living situation and recovery status are worthy study.

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