MS

Mansi SinghAIR 126

Question 6Answer in 150 wordsGS1GS1

How are ocean trenches formed? Describe the significant characteristics of these oceanic relief formations. (Answer in 150words)

Open scan (p.17)

Introduction

Ocean trenches are valleys formed at border of continental plate. These are the lowest points of ocean relief. (Eg Mariana Trench formation)

22 words

Main Body

Formed due to convergence between continental oceanic plate at convergent area -> Oceania plate due to heavy density, subduct under continental plate and form trenches.

eg. Java trench in Indian ocean.

Characteristics of these relief formations:

1Act as subduction zone and led to subduction of new plate formed at mid-oceanic ridge.
2Area of deep-seated earthquakes and are earthquake prone.

(Eg Ring of fire in pacific ocean.)

3Marks the end of continental plate and start of oceanic relief.
4Tsunamis due to earthquakes and waves formed as trenches.
5Important for releasing stresses formed at earths crust.

Thus, oceanic trenches play vital role in tectonic plate theory as proposed by Mckenzie.

113 words8 paragraphs

Conclusion

Thus, oceanic trenches play vital role in tectonic plate theory as proposed by McKenzie.

14 words

Diagram

Diagram showing trench formation: convergent plate boundary with continental plate and oceanic plate, showing subduction of oceanic plate under continental plate, and formation of trench

  • Clear definition of ocean trenches
  • Explains mechanism of formation (convergence and subduction)
  • References plate tectonic theory
  • Provides specific examples
  • Identifies trenches as lowest oceanic points

Topper

Mansi Singh

AIR 126

Subject & Paper

GS1GS1

Topic

Salient features of World's Physical Geography

Oceanic relief and plate tectonics

Ocean trench formation

Writing Stats

149

Total words

8

Paragraphs

analytical, geological

Tone