Sand Spit: A Migrating Peninsula
Presque Isle is a recurving sand spit. The neck of the peninsula is attached to the mainland four miles west of downtown Erie. The park creates Presque Isle Bay, a wide and deep harbor for the city of Erie. The bay attracts many pleasure boats and worldwide freighters, making Erie an important Great Lakes shipping port. Geologists believe over time the coastline "floated" as the forces of wind and water carried sand from the neck of the peninsula eastward, depositing it at Gull Point and causing the Gull Point area to grow. This growth and migration of the peninsula occurred rapidly, at least in geologic time. Scientists believe that the peninsula has moved eastward one-half mile per century, although they see smaller changes every year. These changes created an extremely diverse and fragile environment. Because of its diversity, Presque Isle is a natural laboratory for viewing the geologic past and watching geologic forces in motion.
Presque Isle's location relates to a ridge of sediment called a moraine that crosses Lake Erie. Huge slowly moving glaciers carrymoraines, consisting of clay, sand and gravel. The glacier that formed the moraine across Lake Erie was a late, minor advance of the last major ice sheet that covered much of northern Pennsylvania. The small glacier moved southward into the valley now occupied by Lake Erie. The moraine marks the location where the glacier stopped, and was left behind as the ice melted away.
As westerly waves wash upon the beaches in a diagonal direction, sand and pebbles carried with them are left on the shore as the waves recede. Upon each wave's rush, they are deposited a little farther east, adding to Presque Isle's eastward growth. Gull Point has been growing for most of the 1900s and continues to do so today. Presque Isle and the bay it creates have played many significant roles in the history of Erie and the nation. The US Government chose this location to build a fleet of ships during the war of 1812 because it formed the only protected harbor on Lake Erie. In 1813, during the battle of Lake Erie, Commodore Oliver Hazard Perry successfully defended Lake Erie against the British with ships that were built on Presque Isle Bay, making a significant mark on the pages of history.
Habitats on Presque Isle include beaches, dunes, grasslands, savannas, mature forests, marshes, swamps, ponds, and lagoons. This diversity has resulted because the sandspit formation moves from west to east, continually washing away and building up lake sands. The oldest areas of the peninsula contain a mature forest while the youngest are areas of recently deposited open sand. In this process, which ecologists call succession, plant communities change over time until a climax community is reached. Thus all stages of succession from bare sand to mature forest can be observed at Presque Isle during an afternoon hike. The ponds and lagoons of Presque Isle also vary in age and exhibit successional stages. The network of seven miles of peninsula trails allows for observations in all of the various habitats.
The listed waypoint is for the new Tom Ridge Center
Liberty Park N 42° 07.862 W 080° 06.536
Dobbins Landing N 42° 08.326 W 080° 05.486
View of Gull Point N 42° 08.657 W 080° 03.921
For the adventurerous try the ferris wheel at Waldameer Park Congrats to MarshMonsters for being the first to do this shot!
THIS EARTHCACHE MAY BE LOGGED BY DOING THE FOLLOWING REQUIREMENTS.
OUTSIDE REQUIREMENTS: A) Post photos of your team/GPSr and Presque Isle State Park from at least 2 of the above listed waypoints and B) send me the answer to : How is the pavment at TREC friendly to the environment?
INSIDE REQUIREMENTS: Enter Tom Ridge Center and post photos of you at your favorite display and send the answer to: What is meant by a "green" building (give a few examples)?.
