Which combination of factors can increase the impact of an earthquake?

• A. Weak vs strong sediment/bedrock
• B. Water content of soil/sediment
• C. Quality of building construction
• D. All of the above

Answer: (D)

The amount of damage from an earthquake depends on how the ground and the built environment respond to shaking. Soft, unconsolidated sediments and materials near the surface tend to slow down seismic waves and trap energy, which can magnify the shaking compared with solid bedrock. Water content matters because saturated soils can experience liquefaction during strong shaking, causing loss of strength and ground instability. The design and construction of buildings determine how well they resist lateral forces; well-built structures and proper anchoring can withstand shaking much better than poorly constructed ones. When soft ground, high water content, and weak construction are all present, the earthquake’s impact is greatly amplified.