Tsunami Hazard Zones: New US Map Shows Places at Risk of Flooding and Tsunamis Amid Rising Sea Levels [NOAA]

Flooding is threatening different coastal areas across the United States amid rising sea levels caused by the melting of glaciers and polar ice caps. In the context of climate change and global warming, the flooding risk is mainly driven by increasing atmospheric and ocean temperatures. Coastlines are also facing threats posed by tsunamis and heavy rain caused by intensifying storms.

In recent years, previous studies have highlighted these risks across the country and in different parts of the world. Now, a new US map by the National Oceanic and Atmospheric Administration (NOAA) makes an accurate outline of the places at risk of coastal flooding and tsunami hazard zones. The map shows some areas along the US coast are also at risk of storm surge during tropical cyclones.

Coastal Flooding Risk

Based on the NOAA's coastal flood hazard map, coastal areas along the US Gulf Coast, including Florida, and parts of the East Coast are at extreme risk of flooding. Whether it is caused by strong waves and rising sea levels. The increasing water volumes of the Atlantic Ocean and Pacific Ocean are putting low-lying areas in at risk of being submerged, threatening multiple coastal communities.

Projections of these natural disasters are long-term, meaning that hazards like floodwaters and tsunamis may worsen in the coming decades. If current greenhouse gas emissions continue, the risks mentioned could continue until the end of the 21^st century, scientists warn. Outside the US, multiple countries and territories also face the looming threat of sea level rise and coastal erosion.

Rising Sea Level Threat

In its 2022 Sea Level Rise Technical Report, the NOAA warns that sea level along the US coastline is expected to rise on an average of 10 to 12 inches (0.25 to 0.30 meters) in the next 30 years or by 2050. The rising sea level threat will vary regionally across the US coasts due to differences in both land and ocean height, the technical report says.

The main threat of sea level rise is coastal flooding, caused by increasing tides and storm surges, that can reach further inland, according to the NOAA. By 2050, it has been estimated that damaging floods are expected to occur more often or 10 times than they are today, the US Government agency adds.

Tsunami Hazard Zones

In the NOAA map, tsunami hazard zones for large waves, as well as coastal flooding, place multiple states in the US in critical danger zones. These areas range from Maine to the Carolinas, Florida to the south, and Texas to the west. While tsunamis are primarily caused by earthquakes, the shift in ocean levels mentioned earlier means the flooding effect could reach further inland.

Globally, tsunami events over the past decades were not only caused by earthquakes but also volcanic eruptions. In 2022, a major explosive eruption occurred at the underwater volcano Hunga Tonga-Hunga Ha'apai in Tonga, generating widespread tsunamis across the Pacific Ocean.