Storegga Slide

Overview

Evidence and claims

Timeline

Local Atlas Map

Documented connections

Sources

Research detail

Topic ID: CM-031 Last reviewed: 2026-08-10 Corrections: /corrections/ Change history: Recorded in the Connected Atlas topic changelog.

Overview

The Storegga Slide was a massive submarine landslide on the Norwegian continental margin. Around 8150 to 8200 years ago, part of the seafloor failed and generated a tsunami that affected coastlines around the North Atlantic, including Norway, Shetland, mainland Scotland, the Faroe Islands, and possibly parts of Greenland and Denmark. The landslide and tsunami are strongly supported by seafloor mapping, sediment cores, tsunami sand layers, radiocarbon dating, and numerical modeling. The public story often connects Storegga to Doggerland, the now-submerged Mesolithic landscape in the southern North Sea. That connection is real, but it is often overstated. Storegga likely caused dangerous regional inundation in some coastal zones, but Doggerland was already shrinking because of postglacial sea-level rise. Current modeling suggests the tsunami was not necessarily the single cause of Doggerland abandonment or final submergence.

Plain-language explanation

The Storegga Slide was a collapse of a large section of the continental slope west of Norway. When the seafloor failed, a huge mass of sediment moved downslope into deeper water. That movement displaced seawater and generated a tsunami. Unlike a mythic flood story, Storegga is not known from an ancient text. It is known from physical evidence. Geologists identify the slide scar on the seafloor, the debris left by the landslide, and sand layers left by the tsunami on distant coasts. Those sand layers can sit inside peat, lake sediment, or coastal deposits. Their elevation, grain size, age, and position help estimate where the wave went and how high it reached.

Historical and scholarly context

Storegga is conventionally understood as a large submarine landslide that generated a major tsunami during the early Holocene. The event is part of a broader pattern of slope instability on glaciated continental margins. Ice-age sediment loading, deglaciation, changing sea level, pore pressure, earthquakes, and sediment weakening are all part of the discussion around why such slides occur.

The strongest evidence is geological, not textual. Tsunami sand layers, seafloor morphology, and numerical models support the core event. The timing near the 8.2 ka cold event makes Storegga easy to connect to wider climate disruption, but timing overlap does not automatically mean one caused the other. Storegga was a tsunami event. The 8.2 ka event involved broader climate and freshwater forcing debates.

Storegga also needs careful placement inside the Younger Dryas cluster. The Younger Dryas ended around 11,700 years ago. Storegga occurred roughly 8,200 years ago. That means Storegga is useful for comparison with catastrophe theories, but it should not be treated as evidence for the Younger Dryas Impact Hypothesis itself.

What the evidence supports

The strongest support is physical. Seafloor mapping identifies the landslide scar and slide deposits. Coastal sediment layers show that a tsunami reached multiple coastlines. Radiocarbon dating places the event around the early Holocene. Numerical models show how a large Norwegian-margin submarine slide could generate the observed North Atlantic tsunami pattern.

For the story network, the strongest support is that people likely lived in some affected regions. Mesolithic communities occupied coastal zones around the North Sea and North Atlantic. Even without written records, it is reasonable to treat Storegga as a real prehistoric disaster that could have shaped local memory and migration decisions.

Limits and disputed claims

• The single-cause Doggerland destruction story is too simple. Rising sea level was already reducing the landscape.

• There is no direct evidence that Storegga produced a named flood myth in later written tradition.

• Claims that Storegga proves Atlantis or a lost advanced civilization are not supported by archaeology.

• Claims that Storegga was caused by a comet, pole shift, or artificial technology are unsupported.

• Population-death estimates should be treated cautiously because they depend on uncertain settlement density, local exposure, tide level, and wave reconstruction.

Claim status

• Well supported: The Storegga Slide was a massive submarine landslide off western Norway around 8,200 years ago.
• Well supported: Around 8.2 ka, the Storegga slide generated a tsunami documented on multiple northern European and North Atlantic coastlines.
• Well supported: The Storegga slide and tsunami are supported by marine mapping and morphometry, field deposits and chronology, and numerical modeling.
• Well supported: Published archaeological literature explicitly examines the Storegga tsunami in relation to Doggerland.
• Active debate: The Storegga–Doggerland relationship is evidence-based, but claims of uniform or total destruction remain contested.
• Active debate: Storegga inundated some coastal zones, while archaeological reassessment cautions that its effects on Doggerland were locally variable and were not the sole process of landscape loss.
• Active debate: Current archaeological reassessments do not establish the Storegga tsunami as the single cause of Doggerland abandonment or final submergence.
• Well supported: It is one of the strongest prehistoric tsunami cases because it has a mapped source slide, sediment deposits, dates, coastal evidence, and numerical models.
• Active debate: The tsunami may have damaged parts of Doggerland, but the listed literature does not establish that it single-handedly destroyed the landscape.
• Misrepresented source: The listed Storegga sources do not establish that the tsunami by itself made Britain an island.
• Misrepresented source: Storegga's approximately 8.2 ka chronology does not make it direct evidence for a Younger Dryas impact.
• Well supported: The Storegga tsunami is dated to about 8.2 ka.
• Well supported: The Storegga Slide generated an early-Holocene regional tsunami documented at northern European and North Atlantic coasts.

Sources

• The Storegga tsunami along the Norwegian coast, its age and run up — https://doi.org/10.1111/j.1502-3885.1997.tb00649.x
• The dating and morphometry of the Storegga Slide — https://doi.org/10.1016/j.marpetgeo.2004.10.008
• The Storegga Slide tsunami—comparing field observations with numerical simulations — https://doi.org/10.1016/j.marpetgeo.2004.10.003
• The catastrophic final flooding of Doggerland by the Storegga Slide tsunami — https://doi.org/10.4312/dp.35.1
• A great wave: the Storegga tsunami and the end of Doggerland? — https://doi.org/10.15184/aqy.2020.49
• Evidence of the Storegga Tsunami 8200 BP? An Archaeological Review of Impact After a Large-Scale Marine Event in Mesolithic Northern Europe — https://doi.org/10.3389/feart.2021.767460

This public draft omits internal numeric scoring and administrative notes. Claim labels describe evidentiary status, not topic importance.