Final answer:
The characteristics of active continental margins include earthquakes, volcanic eruptions, and deep-sea trenches, but not a broad continental shelf. Active margins are linked to convergent plate boundaries where subduction causes geological activity, as opposed to passive margins with broad shelves and extensive sediment deposition.
Step-by-step explanation:
Characteristics of active continental margins include features like deep-sea trenches, volcanic and earthquake activity, which are linked to the dynamic interactions at tectonic plate boundaries. However, a broad continental shelf is not a characteristic of active continental margins but rather of passive margins, where tectonic activity is minimal.
Active continental margins are often the location of significant earthquakes and volcanic eruptions. This is due to the presence of convergent plate boundaries, where an oceanic plate is subducted beneath a continental plate, leading to mountain building and deep-sea trenches such as the Mariana Trench. The geological activity creates a thinner sediment accumulation due to the ongoing orogenesis, rather than the extensive delta formations associated with broad continental shelves and lowstands in sea level, which typify passive margins.