In fact, earthquakes occur repeatedly in Arcpunk. Naturally, they are not geologically motivated, as the Chunks are not tectonic plates. Instead, there are frequent gravitational "hiccups" that cause essentially the same effects as an earthquake. For this very reason, many communities and peoples build quite sturdy houses. While these tremors are rarely strong enough to cause massive damage, severe quakes do pose a serious problem - especially when the Vastor ports are affected.
Because Vastor ships (Ships that "fly" through the Vastor - the gravity-free, air-filled space between the world-shards aka Chunks), due to their vertical gravitational axis, cannot simply land on or above Chunks without causing massive interference. Consequently, they rely on ports for safe docking. If these are destroyed or dysfunctional, specialized ships or natural harbors are required to make the Chunk "accessible" again. Since many Chunks are no longer self-sufficient, this becomes the primary threat, far outweighing the direct damage caused by the disaster itself.
Last but not least, such eventualities drive many Chunks (world-shards) to join the CCG (Constance of Capital Gains). This hegemony possesses sufficient resources and technology to provide rapid assistance - purely to ensure the market continues to function and capital keeps flowing.
Various forms of vastor ships