Tomato Soup EarthCache

🥫 Tomato Soup 🥫 

Here we are at the mouth of the remarkable Harecastle Tunnel (or sometimes Scarecastle, as it is well known for the tunnel boggart 👻 ) 

By the 1820s, canal traffic was at a bottleneck. Engineer Thomas Telford created a second tunnel in only took three years, thanks to advancements in technology. Having two tunnels was much better as it reduced wait times at the tunnel entrance.

Today, you can only access Telford’s tunnel. The original tunnel was closed in 1914 due to subsidence, and the network of mining canals remain unexplored since the 1960s.

Access to the tunnel is by narrowboat only, so please do not attempt to enter the tunnel on foot - you’ll get very wet! 

Seepage! 

The flow of water through the soil or ground is called seepage. But seepage meaning does not only limit itself to water but other fluids as well. Thus, seepage meaning is the flow of any fluid through the soil or the ground. Seepage is often a critical problem in geology.

Minerals and how they effect the water…

Sometimes seepage can contain minerals from the surrounding environment, here are some examples of how certain minerals can effect water;

• Iron - Iron-rich minerals can cause water to appear red or brown. When iron is in solution in water with low oxygen levels, it can precipitate out as iron hydroxide, which can give water a red tint. 
• Manganese - Manganese-rich minerals can cause water to appear black. 
• Calcium carbonate - Limestone contains calcium carbonate, which can cause water to appear blue. 

And now some questions… let’s see what you can figure out! 

Please remember that this is about having fun and learning something so don’t worry too much, but please do remember to send your answers! ☺️

1. Please describe the colour of the water on your visit
2. Why do you think the water appears this colour? 
3. What does your answer to Q2 tell you about rock found in the local geology?
4. Please post a photo of yourself or a personal item around the tunnel entrance (or inside if you are going through on a narrowboat)