Scientists Discover Amber Deposits in Japan That Contain Evidence of a Tsunami From 115 Million Years Ago

Recent findings in Japan have provided experts with more clarity regarding events in the dinosaur age. It is well-known that an asteroid impact drew curtains on the age, however, a recent set of evidence from Japan suggests that it wasn't the only disaster that befell Earth in that period. Evidence of the ancient tsunami was spotted in tree amber from the 'Age of Dinosaurs,' according to Live Science. The proof was explained in detail within a study published in Scientific Reports.

Researchers during the analysis of tree amber dating back to the dinosaur age, found peculiar deformities in it. This probed them to conduct further examination, which revealed that the deformities indicated the sweeping away of tree and plant debris, around 115 million years ago. Experts believe this to be evidence of a tsunami-like event.

For the study, researchers specifically focused on the amber-filled silica deposits at the Shimonakagawa Quarry, according to Discovery Magazine. Experts had previously determined that these deposits arrived at the site when the place was still covered in water. Fluorescence imaging revealed well-preserved flame-shaped deformations in the tree amber deposit. Analysis showcased that the deformations were facilitated on the amber at the time of deposition, when it was still soft. This implies that the amber was transported directly from land to water, and thereafter never had the chance to go into the open-air atmosphere. Therafter, the amber sank deeper and solidified on the ocean floor.

The sample was located at Hokkaido Island in its deep-sea sediments. Experts think the tsunami's impact moved the then-soft tree resin from the forest to the ocean floor. Here, the resin settled and later became solidified. According to experts, the most plausible cause behind the tree amber's presence in the deep-sea environment is a large-scale tsunami. Though they are yet to determine whether the event included one or more tsunamis. Based on the fact that amber was present in Early Cretaceous deep-sea deposits implies that a possible tsunami occurred somewhere between 116 and 114 million years ago. 

The assertion was backed by other evidence found in Hokkaido, which indicated that landslides and, thus, earthquakes happened in the region during the Early Cretaceous period. In the analyzed sediment, experts also found masses of tree trunks, mud, and other plant material, which also points more towards a tsunami than a storm.

The finding is valuable because spotting evidence of ancient tsunamis has been difficult for researchers worldwide. Though tsunamis leave their traces on objects, and also sweep them across long distances, the preserving potential of these traces is deemed to be low. Experts also face difficulty in distinguishing between storm and tsunami deposits. Over the years, researchers have found similar signs left by tsunamis, cyclones, and typhoons in their aftermath, which makes the categorization more difficult.

This evidence suggests that proof of tsunamis can be located in deep-sea sediments. The amber resin in the Hokkaido site implied a kind of rapid movement, which can only be produced by tsunamis. This gives future experts a new way to identify and potentially analyze the aftereffects of ancient tsunamis.