By Nat Hab Expedition Leader Eddy Savage
Iceland is dwelling to a number of the most spectacular and photogenic waterfalls on the earth. These waterfalls don’t essentially have enormous quantities of water flowing over them, however the rugged and distinctive panorama surrounding them provides to their attraction and sweetness. The range of recent and previous volcanic landforms offers for an distinctive array of waterfalls. Iceland could 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. As it pulls aside, about an inch per yr, 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 energetic volcanic techniques and new lava flows, or new land. In 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
Kvernufoss
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 beneath an ice sheet, the warmth from the lava interacting with the chilly ice creates an extremely sturdy, pressured and explosive eruption. This can set off a glacial outwash flood that always attains stream equal to the most important rivers on the earth for a brief time frame. The burst of water finds its means right down to the ocean and erodes the land in its means.
Peering out from behind Seljalandsfoss © Eddy Savage
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. During the eruptions, layer upon layer of igneous breccia (small rock fragments), hyaloclastite (compacted ash and different superb particles), and basalt lava flows accumulate to create tuya mountains (desk mountains) and Moberg ridges (hyaloclastite ridges). We will name it “igneous sedimentary rock” for the aim of this text.
You can solely discover these “igneous sedimentary rock” areas throughout the youthful areas of Iceland. The land should be lower than 2.5 million years previous and have been coated in ice through the eruption part for these formations to seem. The south of Iceland has some iconic waterfalls that carve their means by way of this terrain.
Three south coast gems—Seljalandsfoss, Kvernufoss and Skogafoss—share an attention-grabbing function: They fall about 200 ft off an “igneous sedimentary rock” cliff.
Travelers journey horseback towards Skogafoss © Eddy Savage
When ice was overlaying 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 ft increased (or the land 150-200 ft decrease) than at this time. When the ice melted, crustal rebound started and, with the burden of ice gone, the cliffs lifted again up 150-200 ft.
The cliffs that these three iconic waterfalls topple over had been an historical seawall the place, for millennia, the ocean would have crashed in opposition to and simply eroded the “igneous sedimentary rock” wall. Because 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 historical shoreline spanning many miles alongside the southern fringe of Iceland.
The Waterfalls of the Eastfjords and Westfjords
Dynjandi waterfall within the 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 stream 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 laborious basalt with their repeated rising and melting. Like a bulldozer, the heavy ice powerfully crushes, plucks and plows by way of even the toughest of rocks. Much of the laborious 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. Instead of carving deep troughs or canyons, the waterfalls right here powerfully crash their means over rugged and jagged mountainsides of stratified basalt, discovering historical fissures within the rock to guide their means right down to the ocean.
Folaldafoss in East Iceland is a good instance of this. Above the waterfall, you possibly can see the stratification layers of basalt. To the left of the waterfall, you possibly can see an intrusive dyke that may have stuffed an historical fissure with lava and made a pure course for water to stream.
Folaldafoss waterfall
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 top of the bigger glacier would have been roughly the identical because the valley ground, permitting the higher, smaller glacier to stream simply into it with out carving the valley a lot decrease. As 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.”
Baejarfoss, Westfjords
Waterfalls are solely a small piece of the expertise of Iceland, however they’re endlessly fascinating. The dynamic means through which Iceland was fashioned and remains to be forming ensures that round each nook there might be one thing new to see. In my opinion, time spent having fun with, exploring and photographing these waterfalls is a spotlight of our Iceland expeditions. I stay up for seeing you over there!
© Eddy Savage