Scientists have uncovered massive ancient landforms beneath the North Sea that were previously unseen (photos included).

Scientists have discovered massive landforms deep beneath the North Sea, suggesting that the region was engulfed by a gigantic ice sheet by the middle of the last glacial period. This topography is buried under a thick layer of sediment. The study has been published in the journal Science Advances, reports Live Science.

In the images obtained by the researchers, features on the North Sea floor correspond to the advance and retreat of a single enormous ice sheet that existed 1 million years ago. This finding contradicts theories suggesting that smaller ice sheets repeatedly expanded and contracted during that time. These theories were based on numerous depressions, which were thought to be caused by glacial movement. However, it turns out these features resulted from strong ocean currents.

The scientists state that they have found compelling evidence of one large ice movement during this period, but areas beyond the current research zone may still hold evidence of several smaller ice sheets.

The authors of the study utilized high-resolution sonar data to uncover hidden topography. They were not searching for anything specific and were surprised to find evidence of a single ice sheet's existence.

Such ice sheets transport sediment as they grow and shrink, creating erosional and depositional landforms that allow scientists to reconstruct the glacial history of the region. According to the researchers, when ice advances, it creates elongated features that shape sediment in the direction of the ice's movement. When the ice retreats, features are formed that show clear boundaries of the ice sheet.

According to the researchers, the massive ice sheet formed during the last glacial period known as the mid-Pleistocene transition, which lasted from 1.3 million to 700,000 years ago. The glacial period itself extended from 2.6 million to approximately 11,700 years ago.

One million years ago, significant climate changes were occurring on Earth, and glacial periods lasted longer with extensive ice movement, prompting scientists to investigate what happened during that time.

The new study does not yet provide answers on where the ice spread during the mid-Pleistocene transition, but it may assist scientists in piecing together the conditions that led to global climate change.

The discovered landforms indicate that the ice sheet covered present-day Norway and extended towards the British Isles. Some of the traces left by its retreat resemble a series of cracks formed when the ice sheet "settled" on soft sediments just before retreating. For thousands of years following the ice sheet's retreat, the landforms were covered by sediment and hidden.

The research offers insights into how ice sheets grow and collapse during climate change.