By Nat Hab Expedition Chief Eddy Savage
Iceland is dwelling to a number of the most spectacular and photogenic waterfalls on the planet. These waterfalls don’t essentially have big quantities of water flowing over them, however the rugged and distinctive panorama surrounding them provides to their appeal and sweetness. The range of recent and previous volcanic landforms supplies for an distinctive array of waterfalls. Iceland may be very younger geologically talking, and the complete island was constructed by 14 to 16 million years of successive above-water volcanic lava flows. Iceland is splitting aside alongside the mid-Atlantic ridge rift zone, which is located in the midst of the island. Because it pulls aside, about an inch per 12 months, it leaves the oldest land to the east and west of the nation and the youngest land within the center. The rift zone is the place we will discover Iceland’s lively volcanic programs and new lava flows, or new land. Within the Eastfjords and Westfjords, the bedrock is between 10 million and 16 million years previous. The completely different age zones of the island present for exceptionally different-looking waterfalls.
The Rift Zone Waterfalls
The Pleistocene, or Ice Ages, began roughly 2.5 million years in the past, staying for 100,000 years, thawing for 20,000 years, after which repeating this cycle since that point. Iceland’s panorama has been distinctly affected by the repeated visitation of ice sheets. Volcanic eruptions beneath the ice sheet (which may have been 1 mile thick in some locations), created distinct landforms. When a volcanic eruption happens below an ice sheet, the warmth from the lava interacting with the chilly ice creates an extremely robust, pressured and explosive eruption. This will set off a glacial outwash flood that always attains move equal to the most important rivers on the planet for a brief time frame. The burst of water finds its method right down to the ocean and erodes the land in its method.
Concurrently, the lava cools exceptionally quick, and ash and different particles have nowhere to go as it’s being trapped by an especially huge and heavy load of ice. In the course of the eruptions, layer upon layer of igneous breccia (small rock fragments), hyaloclastite (compacted ash and different positive particles), and basalt lava flows accumulate to create tuya mountains (desk mountains) and Moberg ridges (hyaloclastite ridges). We’ll name it “igneous sedimentary rock” for the aim of this text.
You may solely discover these “igneous sedimentary rock” areas inside the youthful areas of Iceland. The land have to be lower than 2.5 million years previous and have been lined in ice through the eruption section for these formations to look. The south of Iceland has some iconic waterfalls that carve their method via this terrain.
Three south coast gems—Seljalandsfoss, Kvernufoss and Skogafoss—share an attention-grabbing characteristic: They fall about 200 toes off an “igneous sedimentary rock” cliff.
When ice was masking the area, the immense weight of the mile-thick ice sheet depressed the island down (like pushing on a reminiscence foam pillow) in order that the traditional shoreline would have been round 150-200 toes greater (or the land 150-200 toes decrease) than at present. When the ice melted, crustal rebound started and, with the burden of ice gone, the cliffs lifted again up 150-200 toes.
The cliffs that these three iconic waterfalls topple over have been an historic seawall the place, for millennia, the ocean would have crashed towards and simply eroded the “igneous sedimentary rock” wall. As a result of this “igneous sedimentary rock” is softer than most different volcanic rock in Iceland, the ocean ate away on the coast and left behind dramatic canyons, cliffs and caves alongside an historic shoreline spanning many miles alongside the southern fringe of Iceland.
The Waterfalls of the Eastfjords and Westfjords
As we transfer to the east and west of Iceland, we head in direction of the older areas of Iceland. The mountains of the east and west have had a special impact from the two.5 million years of ice ages. The land is comprised of layer upon layer of basalt lava move intermixed with intrusive dykes (from fissures the place an eruption occurred). This panorama begins to look extra like a purposefully carved layer cake than the rugged and crumbling rifting areas. The ice sheets carved huge u-shaped valleys into the onerous basalt with their repeated rising and melting. Like a bulldozer, the heavy ice powerfully crushes, plucks and plows via even the toughest of rocks. A lot of the onerous work in shaping the land has already been carried out by the ice sheets, and the waterfalls don’t have an excessive amount of sway in re-shaping the hardened basalt rock panorama. As a substitute of carving deep troughs or canyons, the waterfalls right here powerfully crash their method over rugged and jagged mountainsides of stratified basalt, discovering historic fissures within the rock to guide their method right down to the ocean.
Folaldafoss in East Iceland is a good instance of this. Above the waterfall, you’ll be able to see the stratification layers of basalt. To the left of the waterfall, you’ll be able to see an intrusive dyke that will have crammed an historic fissure with lava and made a pure course for water to move.
Möngufoss within the Westfjords is one other nice instance of this. It carries much more proof of the previous ice ages wreaking erosive havoc on the basalt lava flows. The watershed for Möngufoss is in a dangling valley. The ice-age glacier that sat on this u-shaped valley above the falls would have fed into a bigger glacier beneath. The peak of the bigger glacier would have been roughly the identical because the valley flooring, permitting the higher, smaller glacier to move simply into it with out carving the valley a lot decrease. Because the ice age ended and the glaciers retreated, the bigger glacier left the fjord beneath, and the smaller glacier valley above was left “hanging,” therefore the time period “hanging valley.”
Waterfalls are solely a small piece of the expertise of Iceland, however they’re endlessly fascinating. The dynamic method wherein Iceland was shaped and continues to be forming ensures that round each nook there will probably be one thing new to see. For my part, time spent having fun with, exploring and photographing these waterfalls is a spotlight of our Iceland expeditions. I sit up for seeing you over there!