trench
Definition
A trench is a long, narrow excavation in the ground. It is typically deeper than it is wide, and it is often used for military purposes.
Trenches can be used for a variety of purposes, including:
- Sheltering soldiers from enemy fire
- Providing cover for troops to attack or defend an area
- Moving supplies and equipment
- Drainage
Trenches are typically dug by hand, but they can also be dug by machines. They can be made of various materials, including soil, sand, and concrete.
The depth and width of a trench will vary depending on its purpose. Trenches used for shelter will typically be deeper than trenches used for drainage.
Trenches can be a dangerous place, as they can collapse or be flooded. Soldiers who use trenches must be aware of these risks and take precautions to stay safe.
How can the word be used?
The trench was filled with water and mud.
Different forms of the word
Noun:
a long, narrow ditch dug in the ground, especially for military purposes.
Verb:
to dig a trench.
Etymology
The word "trench" comes from the Old French word "tranchier", which means "to cut".
The first recorded use of the word "trench" in English was in the 14th century.
The word "trench" is an Old French word, and it is related to the Italian word "trincea" and the Spanish word " trinchera".
Question
What is a trench?
AQA Science Exam Question and Answer
Question:
Define what a trench is in the context of Earth's geology and explain how it forms. Describe the major tectonic process that leads to the creation of trenches and discuss the potential hazards associated with trenches in oceanic regions.
Answer:
A trench in Earth's geology refers to a deep, elongated depression in the ocean floor. It is typically formed through a tectonic process known as subduction, which occurs at convergent plate boundaries where one tectonic plate is forced beneath another.
Subduction begins when an oceanic plate collides with a continental or another oceanic plate. Due to differences in density, the denser oceanic plate is forced beneath the less dense plate. As the oceanic plate descends into the Earth's mantle, it generates a trench on the ocean floor. The pressure and heat in the mantle cause the subducted plate to melt partially, forming magma that can lead to volcanic activity.
Trenches are associated with various hazards, primarily due to their role in generating powerful geological phenomena. Subduction zones can trigger massive earthquakes, often exceeding magnitude 8.0, resulting in destructive tsunamis that threaten coastal regions. Additionally, volcanic eruptions along the trenches can release ash, gases, and lava flows, affecting local and global climates.
An example of a trench is the Mariana Trench in the western Pacific Ocean, which is the deepest known point on Earth. It formed due to the subduction of the Pacific Plate beneath the smaller Mariana Plate. This process highlights the dynamic nature of Earth's geology and the significant geological features that result from tectonic interactions.