About the Homer Spit:
The Homer Spit is a geographical landmark located in Homer, Alaska on the southern tip of the Kenai Peninsula. The spit is a 4.5-mile (7.2 km) long piece of land jutting out into Kachemak Bay. The spit is also home to the Homer Boat Harbor. The harbor contains both deep and shallow water docks and serves up to 1500 commercial and pleasure boats at its summer peak. Some theories postulate that the spit it was pushed into place by now-retreated glaciers. The spit is made up of glacial moraines. In 1899, the Cook Inlet Coal Fields Company laid a railroad track along the spit, connecting the docks to the coal fields along Kachemak Bay. The resulting business led to the development of what eventually became Homer, Alaska. The 1964 Alaska earthquake shrank it to 508 acres (2.06 km2), and killed most of the vegetation, making it today mostly gravel and sand.
What is a spit?
A spit or is a deposition bar or beach landform off coasts or lake shores. It develops in places where re-entrance occurs, such as at a cove's headlands, by the process of longshore drift by longshore currents. The drift occurs due to waves meeting the beach at an oblique angle, moving sediment down the beach in a zigzag pattern. This is complemented by longshore currents, which further transport sediment through the water alongside the beach. These currents are caused by the same waves that cause drift. Spits occur when longshore drift reaches a section of headland where the turn is greater than 30 degrees. The spit will continue out into the sea until water pressure (e.g. from a river) becomes too great to allow the sand to deposit. Vegetation may then start to grow on the spit, and the spit may become stable and often fertile. A spit may be considered a special form of a shoal. As spits grow, the water behind them is sheltered from wind and waves, and a salt marsh is likely to develop. Wave refraction can occur at the end of a spit, carrying sediment around the end to form a hook or recurved spit.
What is a moraine?
A moraine is any glacially formed accumulation of unconsolidated glacial debris that occurs in both currently and formerly glaciated regions on Earth, through geomorphological processes. Moraines are formed from debris previously carried along by a glacier, and normally consist of somewhat rounded particles ranging in size from large boulders to minute glacial flour.
The size of moraines can be determined by the Udden-Wentworth scale:
-
Cobbles (64 - 256mm or 2.5 - 10.1in)
-
Gravel (4 - 64mm or 0.157 - 2.5in)
-
Granule (2 - 4mm or 0.079 - 0.157in)
-
Sand (0.25 - 2mm or 0.010 - 0.079in)
Logging Requirements:
-
Based on your observations at the GZ and some information in the description, describe some distinct characteristics of a spit that you notice at the GZ.
-
Examine the predominant type of moraine at Coal Point. What size is the sediment at the GZ and how is it classified according to the Udden-Wentworth scale?
-
As of June 2019, earthcaches are now allowed to have a required photo logging task. Please provide a photo of yourself, your GPSr, or a personal item that proves that you have visited this site. Please post this in your log.
**Confirm your find by answering these questions on this Google Form or by sending your answers to us via message center**
Sources:
https://en.wikipedia.org/wiki/Homer_Spit
https://www.alaska.org/detail/the-homer-spit
https://en.wikipedia.org/wiki/Moraine
Enjoyed finding this EarthCache? Consider awarding it a favorite point!
| We have earned GSA's highest level: |
 |
