Explore these NOVA resources to better understand the volcanology behind Tonga’s massive undersea eruption in January.

A link between volcanic activity and rising bubbles of low pressure in the ionosphere has now been proven, which may be why the colossal Tonga volcano eruption in 2022 disrupted satellite communications

The destruction of telecommunications cables during the eruption of Hunga Tonga-Hunga Haʻapai volcano in 2022 shows that underwater debris currents can travel at 122 kilometres per hour

Millions of tonnes of water vapour have been lingering in the atmosphere since the Hunga Tonga-Hunga Ha’apai volcano erupted in 2022– possibly contributing to global warming

Peruvian President Pedro Castillo declared an environmental emergency after an oil spill from high waves caused by the Tonga volcanic eruption contaminated several beaches. Photo: Martin Mejia/Associated Press

Satellite images show parts of the Pacific nation of Tonga before and after a tsunami triggered by an underwater volcanic eruption damaged the archipelago’s coastline. Vast areas were blanketed in ash. Photos: Maxar Technologies/Reuters

EXCLUSIVE: Billy Vunipola has played a supporting role in rugby's version of House of Cards. The No 8 turned political pawn as his name was touted in promises for World Rugby elections

EXCLUSIVE: Billy Vunipola has played a supporting role in rugby's version of House of Cards. The No 8 turned political pawn as his name was touted in promises for World Rugby elections

Known as the 'crown jewel' of U.S. national forests, this ancient ecosystem is at a crossroads.

In spring and summer of 2008 and 2009, sawmill production capacity and utilization information was collected from major wood manufacturers in southeast Alaska. The estimated mill capacity in southeast Alaska for calendar year 2007 was 292,350 thousand board feet (mbf) (log scale), and for calendar year 2008 was 282,350 mbf (log scale).

In spring 2004 and 2005, sawmill capacity and wood utilization information was collected for selected mills in southeast Alaska. The collected information is required to prepare information for compliance with Section 705(a) of the Tongass Timber Reform Act. The total capacity in the region (active and inactive mills) was 370,350 thousand board feet (mbf) Scribner log scale during both calendar (CYs) 2003 and 2004. The capacity of active mills for the same periods was 255,350 mbf. This is a 7.4-percent increase in active capacity from CY 2002 (237,850 mbf) to CY 2004. The actual volume of material processed during CY 2004 was 31,027 mbf Scribner log scale. This is a 21.9-percent reduction over CY 2002 (39,702 mbf Scribner log scale).

We describe a protocol to monitor the effectiveness of the Tongass Land Management Plan (TLMP) management standards for maintaining fish habitat. The protocol uses juvenile coho salmon (Oncorhynchus kisutch) in small tributary streams in forested watersheds. We used a 3-year pilot study to develop detailed methods to estimate juvenile salmonid populations, measure habitat, and quantitatively determine trends in juvenile coho salmon abundance over 10 years. Coho salmon have been shown to be sensitive to habitat alterations, and we use coho salmon parr as the primary indicator in the protocol. A priori criteria for type I and type II error rates, effect size, and sample sizes for the protocol were derived with estimates of variance computed from the 3-year pilot study. The protocol is designed to detect trends in abundance of coho salmon parr, as well as coho salmon fry and Dolly Varden (Salvelinus malma), in small streams managed according to TLMP standards and guidelines and to compare these to trends in unmanaged (old-growth) watersheds. Trends are adjusted to account for statistically significant habitat covariates. This information provides an important element in monitoring land management practices in the Tongass National Forest. The methods we describe may have application to monitoring protocols elsewhere for fish populations and land management practices.

In spring 2006 and 2007, sawmill capacity and wood utilization information was collected for selected mills in southeast Alaska. The collected information is required to prepare information for compliance with Section 705(a) of the Tongass Timber Reform Act. The total estimated design capacity in the region (active and inactive mills) was 289,850 thousand board feet (mbf) Scribner log scale in calendar year (CY) 2005 and 284,350 mbf in CY 2006. The estimated design capacity of active mills was 259,850 mbf for CY 2005 and 247,850 mbf for CY 2006. This is a 2.9-percent decrease in active design capacity from CY 2004 (255,350 mbf) to CY 2006. The estimated volume of material processed during CY 2006 was 32,141 mbf Scribner log scale. This is a 3.6-percent increase over CY 2004 (31,027 mbf Scribner log scale).

In spring and summer of 2010 and 2011, sawmill production capacity and wood utilization information was collected from major wood manufacturers in southeast Alaska. The estimated mill capacity in southeast Alaska for calendar year (CY) 2009 was 249,350 thousand board feet (mbf) (log scale), and for CY 2010 was 155,850 mbf (log scale), including idle sawmills. Mill consumption in CY 2009 was estimated at 13,422 mbf (log scale), and for CY 2010 was 15,807 mbf (log scale). Wood products manufacturing employment in southeast Alaska increased from 57.5 full-time equivalent positions in 2009 to 63.5 in 2010 despite the loss of 23,500 mbf of capacity in two sawmills owing to fires, the decommissioning of one large sawmill (65,000 mbf), and equipment sales at two small mills (5,000 mbf).

This report documents the results from the first “5-year” round of understory responses to the Tongass-Wide Young-Growth Studies (TWYGS) treatments, especially in relation to their effects on food resources for black-tailed deer (Odocoileus hemionus sitkensis). Responses of understory vegetation to precommercial silviculture experiments after their first 4 to 8 years posttreatment were analyzed with the Forage Resource Evaluation System for Habitat (FRESH)-Deer model. The studies were conducted in western hemlock (Tsuga heterophylla)-Sitka spruce (Picea sitchensis) young-growth forests in southeast Alaska. All four TWYGS experiments were studied: (I) planting of red alder (Alnus rubra) within 1- to 5-year-old stands; (II) precommercial thinning at narrow and wide spacings (549 and 331 trees per hectare, respectively) in 15- to 25-year-old stands; (III) precommercial thinning at medium spacing (420 trees per hectare) with and without pruning in 25- to 35-yearold stands; and (IV) precommercial thinning at wide spacing (203 trees per hectare) with and without slash treatment versus thinning by girdling in >35-year-old stands. All experiments also included untreated control stands of identical age. FRESHDeer was used to evaluate the implications for deer habitat in terms of forage resources (species-specific biomass, digestible protein, and digestible dry matter) relative to deer metabolic requirements in summer (at two levels of requirements—maintenance only vs. lactation) and in winter (at six levels of snow depth).

Carbon storage and flux estimates for the two national forests in Alaska are provided using inventory data from permanent plots established in 1995–2003 and remeasured in 2004–2010. Estimates of change are reported separately for growth, sapling recruitment, harvest, mortality, snag recruitment, salvage, snag falldown, and decay. Although overall aboveground carbon mass in live trees did not change in the Tongass National Forest, the Chugach National Forest showed a 4.5 percent increase. For the Tongass National Forest, results differed substantially for managed and unmanaged forest: managed lands had higher per-acre rates of sequestration through growth and recruitment, and carbon stores per acre that were higher for decomposing downed wood, and lower for live trees and snags. The species composition of carbon stores is changing on managed lands, with a carbon mass loss for yellow-cedar but increases for red alder and Sitka spruce. On unmanaged lands, the Chugach National forest had carbon mass increases in Sitka spruce and white spruce, and the Tongass National Forest had increases in western redcedar and red alder.

A chronology of key events

Key facts, figures and dates

Swimming with Whales off Tonga

Research Event

Event participants

Lord Tu'ivakano, Prime Minister of the Kingdom of Tonga

ADB today approved a $200,000 (460,000 pa’anga) grant to the Government of Tonga to help restore life-sustaining services following the damage from Tropical Cyclone Harold.

The Pacific Disaster Resilience (PDR) Program program allocates $15 million in policy-based loans and ADF grants for Samoa, Tonga, and Tuvalu when disasters occur and also supports priority actions for disaster risk management.

IP Addresses in Tonga decreased to 422 IP in the first quarter of 2017 from 522 IP in the fourth quarter of 2016. IP Addresses in Tonga averaged 1111.72 IP from 2007 until 2017, reaching an all time high of 2402 IP in the fourth quarter of 2014 and a record low of 189 IP in the fourth quarter of 2015. This page includes a chart with historical data for TongaIP Addresses.

Temperature in Tonga increased to 21.88 celsius in August from 21.83 celsius in July of 2013. Temperature in Tonga averaged 23.24 celsius from 1867 until 2013, reaching an all time high of 27.39 celsius in February of 2004 and a record low of 19.30 celsius in September of 1885. This page includes a chart with historical data for Tonga Temperature.

Tonga scored 31 points out of 100 on the 2011 Corruption Perceptions Index reported by Transparency International. Corruption Index in Tonga averaged 26.40 Points from 2007 until 2011, reaching an all time high of 31 Points in 2011 and a record low of 17 Points in 2007. Corruption Index in Tonga is reported by the Transparency International. The Corruption Perceptions Index ranks countries and territories based on how corrupt their public sector is perceived to be. A country or territory’s score indicates the perceived level of public sector corruption on a scale of 0 (highly corrupt) to 100 (very clean). This page provides the latest reported value for - Tonga Corruption Index - plus previous releases, historical high and low, short-term forecast and long-term prediction, economic calendar, survey consensus and news.

Tonga is the 95 least corrupt nation out of 175 countries, according to the 2011 Corruption Perceptions Index reported by Transparency International. Corruption Rank in Tonga averaged 121.60 from 2007 until 2011, reaching an all time high of 175 in 2007 and a record low of 95 in 2011. The Corruption Perceptions Index ranks countries and territories based on how corrupt their public sector is perceived to be. A country or territory's rank indicates its position relative to the other countries and territories in the index. This page provides the latest reported value for - Tonga Corruption Rank - plus previous releases, historical high and low, short-term forecast and long-term prediction, economic calendar, survey consensus and news.

The Gross Domestic Product per capita in Tonga was last recorded at 5696.20 US dollars in 2018, when adjusted by purchasing power parity (PPP). The GDP per Capita, in Tonga, when adjusted by Purchasing Power Parity is equivalent to 32 percent of the world's average. GDP Per Capita Ppp in Tonga averaged 4733.80 USD from 1990 until 2018, reaching an all time high of 5746 USD in 2017 and a record low of 3577.40 USD in 1990. The GDP per capita PPP is obtained by dividing the country’s gross domestic product, adjusted by purchasing power parity, by the total population. This page provides - Tonga GDP Per Capita PPP - actual values, historical data, forecast, chart, statistics, economic calendar and news.

Deposit Interest Rate in Tonga decreased to 2.84 percent in 2018 from 3.02 percent in 2017. Deposit Interest Rate in Tonga averaged 5.28 percent from 1980 until 2018, reaching an all time high of 7.25 percent in 1990 and a record low of 2.82 percent in 2013. The Deposit Interest Rate is the average rate paid by commercial banks to individuals or corporations on deposits. This page includes a chart with historical data for Deposit Interest Rate in Tonga.

Tonga is ranked 103 among 190 economies in the ease of doing business, according to the latest World Bank annual ratings. The rank of Tonga deteriorated to 103 in 2019 from 91 in 2018. Ease of Doing Business in Tonga averaged 71.08 from 2008 until 2019, reaching an all time high of 103 in 2019 and a record low of 46 in 2008. The Ease of doing business index ranks countries against each other based on how the regulatory environment is conducive to business operationstronger protections of property rights. Economies with a high rank (1 to 20) have simpler and more friendly regulations for businesses. This page includes a chart with historical data for Ease of Doing Business in Tonga.

The Sales Tax Rate in Tonga stands at 15 percent. Sales Tax Rate in Tonga averaged 13.57 percent from 2014 until 2020, reaching an all time high of 15 percent in 2015 and a record low of 5 percent in 2014. In Tonga, the sales tax rate is a tax charged to consumers based on the purchase price of certain goods and services. The benchmark we use for the sales tax rate refers to the highest rate. Revenues from the Sales Tax Rate are an important source of income for the government of Tonga. This page provides - Tonga Sales Tax Rate | VAT - actual values, historical data, forecast, chart, statistics, economic calendar and news.

The Corporate Tax Rate in Tonga stands at 25 percent. In Tonga, the Corporate Income tax rate is a tax collected from companies. Its amount is based on the net income companies obtain while exercising their business activity, normally during one business year. The benchmark we use refers to the statutory rate for Corporate Income. This page provides - Tonga Corporate Tax Rate- actual values, historical data, forecast, chart, statistics, economic calendar and news.

The Gross Domestic Product (GDP) in Tonga was worth 0.46 billion US dollars in 2019, according to official data from the World Bank and projections from Trading Economics. The GDP value of Tonga represents 0 percent of the world economy. GDP in Tonga averaged 0.21 USD Billion from 1975 until 2019, reaching an all time high of 0.47 USD Billion in 2012 and a record low of 0.03 USD Billion in 1976. The gross domestic product (GDP) measures of national income and output for a given country's economy. The gross domestic product (GDP) is equal to the total expenditures for all final goods and services produced within the country in a stipulated period of time. This page provides the latest reported value for - Tonga GDP - plus previous releases, historical high and low, short-term forecast and long-term prediction, economic calendar, survey consensus and news.

Imports from Tonga in Australia remained unchanged at 0 AUD Million in March from 0 AUD Million in February of 2020. Imports from Tonga in Australia averaged 0 AUD Million from 1988 until 2020, reaching an all time high of 1 AUD Million in December of 2016 and a record low of 0 AUD Million in February of 1988. This page includes a chart with historical data for Australia Imports from Tonga.