This section contains information about Glaciology and other glaciers in Iceland (that do not have links in the menu) as well.
First, lets start with some common questions that are asked by clients while on a tour:
*Click the sentence to be taken to the answer*
- Intro Glaciers in Iceland
- Why is Glacier Ice Blue?
- How does a Glacier Move?
- What are these cones (dirt cones)?
- What is an outlet Glacier?
- What are Moraines and how are they formed?
1. Approximately 11% of Iceland’s total area of roughly 100.000 km2 is covered by glaciers.* Geologist believe that Iceland’s Glaciers had more or less disappeared at the end of the last Glaciation, around 9-11,000 years ago. Th present glaciers are therefore not remains of Ice Age Glaciers; rather they are for the most part formed in the last few thousand years.
Here is the skinny: The Red (long wavelength) part of white light causes H2O molecules to vibrate thereby absorbing Orange, Yellow and Green. The color Blue (short wavelength) light is transmitted and scattered, therefore made visible.
In the Gif below white light is being separated into separate parts. Each individual wavelength is also visible starting with Red which is a longer wavelength (think the pulse of a walking person) and violet at the other end (think the pulse of a person running).
3. In short they are remnants of Crevasses or Moulins which have since melted and left what would have been the ash-covered bottom of the aforementioned glacier formations due to the process by which ash acts as an insulator if found to be over 7cm in a particular area.
These cones are basically volcanic ash and other debris which were either deposited on the glacier during volcanic eruptions or during its advance and or retreat through the process of rubbing / fracturing of an object (cliff or hill-side) in its path.
Below is a picture taken from “The Origins of Dirt Cones on Glaciers” by Charles Swithinban. If you were to imagine that the latter (a) to (e) represents significant glacier melt, one may grasp the idea of dirt cones. There is a very detailed explanation at this link
4. A valley glacier which drains an inland ice sheet or ice cap and flows through a gap in peripheral mountains.*
In plain English: I ask the guests if they make pancakes. They often reply with “yes” to which I reply “When you pour a pancake but are really excited and pour a little too much, you get these little drips coming from the pancake; those drips are what an outlet glacier it to an ice cap.” The Ice cap had an oversupply of ice and pushed off its excess weight to make this outlet glacier.
5. The glacier acts as a giant bulldozer, pushing rocks and debris on its journey down the valley. When the glacier recedes it leaves a cargo of rocks and dirt in hills along its margins (flanks) and at its toe, forming lateral and terminal moraines (or end moraines) respectively, as noted in Glacier Mountaineering by Andy Tyson.