When you look at a picture, do you just see the obvious? Or are you one of those people who dig beneath the surface to find out what is hidden underneath? Do you ask 'what if' questions about what is in the picture? Asking questions and digging beneath what is plainly seen is a great way to come up with ideas for stories.
Below is a picture of an exploding volcano. I have never seen a volcano erupt, but the picture is beautiful and offers so many different ideas for a story.

An exploding volcano would be an inspiring, yet terrifying, thing to see. The lava is shooting high into the air, running down the sides of the volcano, and traveling on until it cools. The sky around it has turned shades of purple and red/orange.
What if you woke up one morning, looked out your bedroom window, and saw this happening? What would you do? Would you crawl back under the covers and go to sleep? I don't think you would. My guess is that you would get out of your house and away from the volcano as fast as you could. What possessions would you grab to take with you? Would you take enough time to grab any of them at all? Or would you just run?
What if you had been kidnapped and dropped down into the volcano before it exploded? Were you intended to be a sacrifice to try and appease the gods? Or were you someone your kidnappers expected to receive a huge ransom for and their efforts were not successful? What if you were on the top of the volcano while it was dormant, and your spouse/significant other pushed you down inside? You were knocked unconsciousness, and when you awoke the volcano was getting ready to explode. Could you have somehow found a place inside where the lava wouldn't get to you and where the heat coming from it wouldn't kill you? Do you succeed in escaping?
What if you are a member of a tribe of people who believe that the gods make the volcano erupt when you made them angry? Would just one member of the community be guilty or would all of them be guilty? Would everyone select just one person to leave behind for the volcano to kill? Or would it be mandatory for all to just sit still and wait on their death.
What if you were an artist? Would you stay and watch the explosion long enough to capture it on film or on canvas? How long would you put yourself at risk to get the perfect picture? And what kind of picture would it inspire you to paint? Think of The Scream painted by Edvard Munch. Could it have been inspired by a volcanic explosion?
The Hawaiian Islands were formed from volcanic lava. What if the lava from this explosion forms a new chain of islands? Would you be willing to be one of its first citizens?
What if you are in an airplane that just happens to be flying over the volcano when it explodes? Would the flight of the plane be disrupted? Would the passengers freak out? What if you were in a hot air balloon overtop the volcano when it exploded?
Can you come up with any more writing prompts from the picture of the exploding volcano? If so, please share them with the rest of us in the forum.

