As you walk along the section of the Ron Moeser Trail between Highland Creek and Port Union Common and enjoy the beautiful views of the Lake Ontario shoreline, you will probably notice a series of artificial structures jutting into the water. These are called groynes and while they are a popular spot for the adventurous to explore, yoga enthusiasts to meditate or even couples to share a romantic moment, they also perform an important function.
The land south of the railway tracks was transformed into a recreational trail through land reclamation begun in the late 1990s. Various man made structures can be seen along this stretch of the trail including the long breakwater just east of the Highland Creek bridge, and the scenic viewpoint just south of Port Union Common. Between these two features is a series of four groynes, which make up the focus of this Earthcache.
Groynes are manmade structures designed to influence water flow and control the movement of sediment. While sometimes found in rivers, they are most commonly associated with coastal areas of seas or oceans, and are typically installed to combat the effects of longshore drift. This can either be done to prevent erosion of shorelines, or to encourage the creation of beaches. The fact that groynes can be found here on Lake Ontario, demonstrates how wild conditions can become on The Great Lakes and explains why they are sometimes referred to as inland seas.
Logging the cache:
While you can tackle this in either direction, the recommendation is to begin your observations at Stage 1 and proceed eastward to Stage 4. The terrain is rated as 1, since observations can be made from the paved trail, but if you want you can get up close by scrambling over the rocky shore. There is also an optional viewpoint to check out if you want a chance to see all four groynes at once. Depending on the weather conditions, attempting this cache may be challenging in winter.
At each stage you need to observe how the groyne has altered the shoreline on both the eastern (left) and western (right) sides. Based on your observations please answer the following questions in a message to me. Please do not post answers on your log!
- Which stage displays the most altered shoreline? Describe how the shoreline has changed.
- Which stage displays the least altered shoreline? Describe these changes in comparison to question 1.
- Is there a common trend at all stages between the east and west side of the groyne or does it vary? Please explain your answer.
- Based on the evidence at each stage, what is the prevailing direction of the water flow in this area?
- Can you think of any factors which contribute to the prevailing direction of the water flow?
- Do you think the placement of these groynes has been effective at reducing the effects of erosion?
- Optional. Upload a picture of yourself or your GPS showing one of the groynes in the background.
We hope you enjoyed this Earthcache and learned a little about the effects of erosion and the measures we can take to control it. There are several other Earthcaches nearby worth checking out, which deal with the power of nature and the force of erosion on Lake Ontario.