For the first of the InterCoastal waterway EarthCaches!
Do not log your find without FIRST sending your answers or your log will be deleted!
The intercoastal waterway has had many changes over the years, speaking in geological time. This particular portion of the waterway has ebbed and flowed over time from both natural erosion and man influenced erosion. Looking North East from the GZ you are looking at the original dredged channel of 1890 and the new channel dredged in 1919. All of this and the natural erosion that occurs on both sides of the waterway can be dramatic in certain specific areas. The shore line at the GZ has been reinforced to prevent further erosion at this location.
The Intracoastal Waterway (ICW) is a 3,000-mile (4,800 km) inland waterway along the Atlantic and Gulf of Mexico coasts of the United States. Some sections of the waterway consist of natural inlets, saltwater rivers, bays, and sounds, while others are artificial canals. It provides a navigable route along its length without many of the hazards of travel on the open sea.
The portions of the intercoastal waterways we will focus on are the natural segments and how they were formed. How they are affected by other changes in and around the waterway and the changes that occurs over geological time.
Florida.1
Introduction
Geology is amazing in that it provides a rational, scientific explanation for landscapes and their accompanying scenery. One does not need an earth science background to be in awe of the Himalayas or the Grand Canyon. But the origin of the Himalayas, for example, and how these mountains affect their own weather to produce the glaciers that have sculpted them provide a scientific perspective that makes them all the more wonderful. Even subtle variations in the Earth’s surface provide geologic narratives. So, in this sense, geology is a powerful tool to understand much of what we see in the physical world and all life contained therein. It is a visual science like no other. Additionally, geologic knowledge leads us to locate critical resources that we consume, provides us with knowledge to protect and conserve those resources and our environment, and provides us a tool to predict and therefore prepare for events that affect our lives. So, geology’s societal relevance is unquestioned.
Those who teach geology can lead students to outcroppings to see the rocks that compose the Earth’s crust and to peer into the Earth’s past. If you live in the western United States, geology is before you in the vistas of the Rocky Mountains, for example. Mountain ranges exhibit extraordi- nary scenic diversity, are pure beauty, and are pure geology— three qualities that should be linked in everyone’s mind. In Florida, on the other hand, with its maximum eleva- tion at only approximately 105 meters (in the Panhandle) and much of south Florida virtually flat, with only a few meters of relief and lying only a few meters above sea level, the geologic past is mostly out of sight (Figure Florida.1). The surface morphology of Florida is dominated mostly by subtle paleoshorelines from previous sea-level highstands, karst-generated lakes, and small river drainage basins (Figure Florida.2). What we see are modern geologic (and biologic) environments—some that are world famous, such as the Everglades, the coral reefs, and the beaches. But, where did all of this come from? Does Florida have a geo- logic history other than the usual mantra about having been “derived from the sea”? If so, what events of the geologic past converged to produce the Florida we see today?
Figure Florida.1 Image of Florida showing topography and basic morphologic features. Much of Florida is low topographically, with the highest elevations associated with the dissected coastal plain in the Panhandle. Ancient shoreline trends are shown cut by the modern river drainage system.
Email your answers first and then log your find.
1) What is the link between natural scenery and geology and which type of geology do you believe is at this location?
2) Why is geology important at this location?
3) What are the primary geomorphologic features that dominate Florida’s topography at this location?
4) What form of erosion control is present at this location?
5) (optional) Post a picture of yourself with your GPS at the GZ
