The plot could involve Percy being tricked into using a powerful, ancient artifact that he doesn't fully understand. As he tries to figure out how to control it, it backfires and causes an earthquake. He then has to find a way to stop the destruction and reverse the effects of the earthquake while also dealing with the consequences of his actions, like the panic among the mortals and the possible damage to the demigod world.
There could be a new, made - up character. This character could be a seer who had foreseen Percy causing the earthquake but was unable to prevent it. Now, this seer has to work with Percy to understand why it happened and how to prevent future disasters. Or it could be a young demigod who looks up to Percy and is now caught in the middle of the chaos Percy has caused and has to learn to be brave and helpful during this crisis.
In such a fanfiction, Percy might be in a situation where his powers are out of control. Maybe he's under the influence of a powerful curse or extremely strong emotions. The earthquake could lead to chaos in the mortal world, with buildings collapsing and people panicking. His friends from Camp Half - Blood would then have to figure out how to stop him and restore balance.
In a fanfiction about Percy Jackson with earthquake and hurricane elements, the story might start with an earthquake caused by an angry god. Percy then has to deal with the aftermath while also preparing for an approaching hurricane that the gods seem to be using as a second wave of destruction. He could call upon his friends from Camp Half - Blood to help evacuate people and fight off any monsters that emerge during the chaos.
Perhaps in the fanfiction, an earthquake reveals an ancient and dangerous artifact. Percy has to deal with the earthquake's destruction and also protect the artifact from falling into the wrong hands during the chaos of a hurricane that follows soon after.
One possible plotline could be Percy accidentally making an earthquake during a battle and then having to deal with the aftermath, like rescuing people. Another could be Percy learning to control his power to create earthquakes as part of his training.
The gods could be the antagonists. They might see Percy's actions that led to the earthquake as a threat to their order and try to stop him, even if his intentions were good.
The plot could involve Percy accidentally triggering the huge earthquake while in a battle against powerful foes. Maybe his powers go out of control and the resulting earthquake shakes the very foundation of the fictional world he is in.
One possible cause could be the loss of a loved one. In many stories, this kind of trauma can lead to depression. Percy might be struggling to come to terms with the death or departure of someone close to him.
Another option is to check out some Percy - related forums. Sometimes fans share their own fanfiction there, including stories about Percy making an earthquake. You can engage with the community and ask if anyone has any good recommendations specifically for this type of fanfiction.