Massive Tongan Eruption Sends Tsunamis Across the Pacific

A massive underwater volcano erupted Saturday, January, 15th near the remote Tonga nation in the south Pacific. The eruption generated immediate buzz across the internet from dramatic satellite imagery and tsunami warnings spread as far as the west coast of the United States. The massive Tonga-Hunga Ha’apai volcano is particularly active, and smaller hydromagnetic eruptions like this event are commonly observed. The violent eruption is generated from a flash vaporization chemical reaction between extruded magma and seawater, causing an explosion. The United States Geological Survey measured the resulting shockwaves as a 5.8 magnitude earthquake. 

The volcano lies 40 miles away from Tonga’s main island, Tongatapu, and its eruption was heard in New Zealand as far as 1,400 miles away. The violent eruption generated a volcanic plume of ash, gas, and steam extending more than 12 miles into the atmosphere, where satellite images were able to reveal their expanse over the event duration and indicate the presence of tsunamis. 

A four-foot tsunami wave crashed into the Tongan capital on its northernmost island, Nuku'alofa, where boats and debris washed ashore. Videos across social media captured the powerful wave easily overcoming seawalls, roads, and fences inundating people’s properties. The impending threat left many Tongan residents rushing to higher ground as tsunamis can often increase with each generated wave. The eruption impacted undersea cable networks leaving many areas of Tonga in a blackout, impacting the island nation’s telecommunications. 

Tsunamis spread rapidly across the Pacific, extending warnings to Japan, Hawai’i, American Samoa, Chile, and the west coast of the USA. Waves up to 5 feet arrived Sunday morning in Chile, Japan, and California ports. Witnesses described the incoming tsunamis as water surges instead of the giant waves depicted in popular films like San Andreas (2015). 

New Zealand has committed an initial aid of more than $300,000 in supplies, technical support, and defense assistance. The eruption is one of the biggest to occur within the last decade, according to the volcanic explosivity index (VEI), used by volcanologists to categorize eruption scale. The VEI measures the plume height and quantity of ejected materials like ash, gas, and magma following an eruption. A VEI closer to 6 would indicate one of the rarest and largest eruptions, capable of sending materials high into the atmosphere generating global cooling effects as sunlight is reflected away from Earth’s surface. Scientists previously estimated this volcano to be capable of only producing eruptions up to a maximum of 2 VEI, but the recent event has not yet been measured. 

Climate Change Projections For 2030 Estimate That Majority Of The World's Population Will Live In Coastal Areas Which Are Exposed To Floods, Storms, and Tsunamis

A publication from Nature demonstrates that satellite observations of floods reveal that the proportion of the population exposed to floods has grown by 24% globally since the turn of the century. That is 10 times more than scientists previously thought, and they estimate that by 2030, climate and demographic change will add 25 new countries to the 32 already experiencing increasing floods and harsh weather conditions. 

The United Nations has chosen to increase international cooperation for developing countries as the theme of this year’s World Tsunami Awareness Day, on November 5th. The UN Secretary-General designated November 5th as World Tsunami Awareness day back in December 2015, and it is meant to call on all countries, international bodies, and civil society to increase understanding of the deadly threat and share innovative approaches to reduce risks. 

The UN Secretary-General, António Guterres, says that “rising sea levels caused by the climate emergency will further exacerbate the destructive power of tsunamis. We must limit warming to 1.5 degrees over pre-industrial averages and invest at scale in the resilience of coastal communities.” Many regions that experience rapid urbanization and growing tourism are prone to tsunamis, and it puts even more people in harm’s way. 

For World Tsunami Awareness Day in 2021, the theme will be the Sendai Seven Campaign. The Sendai Seven Campaign –"7 targets, 7 years" was launched in 2016 by the United Nations Secretary-General, with the main objective of promoting the seven targets of the Sendai Seven Campaign over seven years, which are the following: 

• 2016 – Target (a): Substantially reduce global disaster mortality by 2030, aiming to lower the average per 100,000 global mortality rate in the decade 2020- 2030 compared to the period 2005-2015

• 2017 – Target (b): Substantially reduce the number of people affected globally by 2030, aiming to lower the average global figure per 100,000 in the decade 2020- 2030 compared to the period 2005-2015;

• 2018 – Target (c): Reduce direct disaster economic loss in relation to global gross domestic product (GDP) by 2030;

• 2019 – Target (d): Substantially reduce disaster damage to critical infrastructure and disruption of basic services, among them health and educational facilities, including through developing their resilience by 2030;

• 2020 – Target (e): Substantially increase the number of countries with national and local disaster risk reduction strategies by 2020;

• 2021 – Target (f): Substantially enhance international cooperation to developing countries through adequate and sustainable support to complement their national actions for implementation of the present Framework by 2030;

• 2022 – Target (g): Substantially increase the availability of and access to multi-hazard early warning systems and disaster risk information and assessments to people by 2030.

Tsunamis are rare events but can be extremely deadly. In the past 100 years, 58 of them have claimed more than 260,000 lives or an average of 4,600 per disaster - more than any other natural hazard.