Final answer:
Soft deltaic sediment in Greater Vancouver poses a risk of liquefaction during earthquakes. Liquefaction occurs when the ground loses its strength and behaves like a liquid, causing buildings and infrastructure to sink or tilt. The water-saturated sediments in these areas are particularly susceptible to liquefaction.
Step-by-step explanation:
Many parts of Greater Vancouver are built on soft deltaic sediment, which makes them particularly susceptible to a certain risk during an earthquake. The primary risk that these areas face is liquefaction. Liquefaction occurs when the ground loses its strength and stiffness during an earthquake, causing it to behave like a liquid. This can result in buildings and infrastructure sinking or tilting, leading to serious damage.
Liquefaction is more likely to happen in areas with loose, water-saturated sediments, such as soft deltaic sediment. During an earthquake, the shaking can cause the water in these sediments to rise, reducing the cohesion between the particles and turning the soil into a quicksand-like material.
For example: If a building is constructed on top of soft deltaic sediment and an earthquake occurs, the ground shaking can cause the water-saturated sediment beneath the building to liquefy. As a result, the building may sink or tilt, leading to structural damage and potentially endangering the lives of the occupants.