A new study has found that the island of Hawaii is fast sinking. Ironically, it was birthed in an exactly opposite process when, a million years ago, the Pacific Island Plate moved on top of a volcanic hotspot, creating islands from the heart of Earth's crust, which are today known to us as Hawaii. 

Advertisment

A study published in the journal Communications Earth & Environment studied subsidence on the island of O’ahu and found stark differences in the rate at which the island was sinking in different parts. Some areas of the island had a subsidence rate of around just 0.6 millimeters per year. However, some regions are sinking 40 times faster than expected, going down a staggering 25 millimetres per year.

Risk of flooding in Hawaii

The researchers have raised alarm about "future flood exposure" in the current scenario. "In rapidly subsiding areas, sea level rise impacts will be felt much sooner than previously estimated, which means that we must prepare for flooding on a shorter timeline," UH Manoa’s Kyle Murray, lead author of the study, said.

Advertisment

Also Read: Youth more worried about money and work than social media, climate or culture war: Poll

The researchers pointed out the reason behind the problem, which is that places built on soft sediment or artificial fill can sink in faster. This includes the industrial areas of Mapunapuna where increased compaction happens as compared to other areas of O’ahu.

The study raises alarm because the long-term estimated rate of sea level rise is around 1.54 millimeters. This is far less than the subsidence rate recorded in the region. 

Advertisment

Efforts to protect Hawaii's shoreline

Scientists fear that this could impact the shoreline much faster than predicted, outpacing flood preparedness efforts. Co-author of the study, Phil Thompson, said that "Mapunapuna subsidence could increase flood exposure area by over 50% by 2050, while compressing flood preparedness timelines by up to 50 years."

Also Read: Climate change is changing behaviour of crocodiles: Study

Climate change is leading to the rise of sea levels, soil erosion, wildfires, hurricanes, flash flooding and other natural disasters. Efforts are on to stabilise the shorelines, but scientists caution that this should be done taking into account the subsidence rate in order to adopt the right strategies in a timely manner.

In Oʻahu, initiatives like Climate Ready O‘ahu are already underway, under which wetlands will be restored and dune systems will be reinforced. However, to make it effective, the rate at which the land is sinking also needs to be factored in.