We all know that volcanoes, especially the active ones, pose risks and hazards to people living near them. Public awareness activities can be very helpful for the people to understand volcanoes so as to mitigate casualties and destruction of property. The international scientific societies knew this very well, this is why the Decade Volcanoes were identified.
The Decade Volcanoes are 16 volcanoes around the world that could be considered as the most hazardous volcanoes on the planet in terms of their proximity to populated areas, as well as their history of large and destructive eruptions. These volcanoes are identified by the International Association of Volcanology and the Chemistry of the Earth’s Interior (IAVCEI).
The Decade Volcanoes project aims to direct public attention to the selected active volcanoes around the world to encourage research and public awareness activities aimed at enhancing the understanding of the volcanoes and the hazards they pose, thus being able to reduce the severity of volcanic eruptions.
These volcanoes are named “Decade Volcanoes” since the project was initiated as part of the United Nations-sponsored International Decade for Natural Disaster Reduction (IDNDR), which refers to 1990 to 2000. In choosing what volcanoes can be designated as a Decade Volcano, they listed those that exhibits more than one volcanic hazard, shows recent activity, is located near a populated area, has local support for the project, and is physically and politically accessible for study.
Since the Decade Volcanoes project is sponsored by the UN, it only covers those nations that are members of the organization. Most of the decisions are based on what is politically feasible, not always on what is scientifically correct and acceptable. Therefore, the volcanoes chosen have to have a broad demographic and geopolitical appeal, to the representative body that has received the funding grant. To achieve a scientifically motivated choice, the chosen volcanoes had to pose a threat to tens and thousands of people with at least two of these volcanic hazards: lava flows, lahars, lava dome collapse, tephra fall, pyroclastic flows, or volcanic edifice instability – plus having a recent volcanic or geologic activity.
Since the program was initiated, the program has achieved a lot of successes, such as predicting volcanic activities and alleviating effects of such. Here is the list of the volcanoes included in the Decade Volcanoes program and some of the accomplishments of the project (as well as some problems encountered) for each of the volcanoes:
1. Avachinsky-Koryaksky – Kamchatka, Russia
Background: Russia’s Avachinsky-Koryaksky has been active for tens of thousands of years. Geological records show that there have been three major eruptions in the last 10,000 years: during 5,500 BC, 1,950 B.C and 1,550 BC. It erupted for the first time in recorded history during 1890. Its latest eruption occurred on December 29, 2008. The volcano has been designated as a Decade Volcano in 1996 in light of its proximity to Petropavlovsk-Kamchatsky.
Project achievement: The IDNDR has performed stratigraphic reconstruction, which revealed at least 112 eruptions in the past 8,000 years. The mass discharge rates were estimated for the larger events.
2. Colima – Jalisco, Mexico
Background: Also known as Volcán de Fuego, Colima is one of the most active volcanoes in Mexico and North America, having erupted more than 40 times since 1576. More than 300,000 residents live within 25 miles from the volcano, making it the most dangerous volcano in Mexico. Its latest eruptions happened in November 2014, January 2015, September and December 2016, and January 2017. Because of its situation in a densely populated area and its history of large eruptions, it has been picked as a Decade Volcano.
Project achievement: Frequent temporary evacuations have been conducted frequently in 1991, and from 1998 to 1999, and they were successfully managed. The larger-than-usual explosion in May 1999 required evacuation of several villages near the foot of the volcano.
3. Mount Etna – Sicily, Italy
Background: Mount Etna is the largest of the three active volcanoes in Italy and the tallest active volcano in Europe. It is also one of the most active volcanoes in the whole planet that is in an almost constant state of activity. In 1928, an eruption caused a large lava flow, leading to the destruction of a population center for the first time since the 1669 eruption. Since the 1991-1993 eruption, Mount Etna has been continuously having intense volcanic activities in the 21st century; and had eruptions in 2001, 2002-2003, 2008-2009, 2015. The latest one happened in March 2017, wherein 10 people were injured.
Project achievement: The program led to a better understanding of the volcanic hazards of Mount Etna. With the advice of the IAVCEI, the lava flow of 1991-1993 was eventually prevented from reaching the town of Zafferana. The authorities and volcanologists dropped blocks into a lava tube, used explosives to breach the tube and divert lava, and built a dam to pond the lava.
4. Galeras – Nariño, Colombia
Background: Galeras is the most active volcano in Colombia and has been active for at least a million years. Its earliest activity was during the Holocene, dated by radiocarbon dating at 7,050 BC to 1,000 years. The eruption that happened on January 2010 forced the evacuation of 8,000 people. The volcano erupted again in August during the same year, but it was non-explosive.
Project achievement: During the Decade Volcano conference in Pasto City in 1993, several scientists present conducted an unplanned expedition to the crater of Galeras. Unfortunately, it ended in a tragedy since an eruption unexpectedly occurred while they were at the summit, resulting in the deaths of six volcanologists and three tourists. Because of this, important lessons were learned about the build-up of gas pressures near the surface. Also, a special issue of the Journal of Volcanology and Geothermal Research was dedicated to the memory of the six scientists.
5. Mauna Loa – Hawaii, United States
Background: Historically been considered as the largest volcano in the planet, Mauna Loa has been erupting for at least 700,000 years. The Mauna Loa eruptions in 1926 and 1950 have destroyed villages – the city of Hilo is actually partially built on lava flows from them. It has been intensively monitored by the Hawaiian Volcano Observatory since 1912.
Project achievement: Scientists have estimated recurrence intervals of volcanic activity by using detailed geologic mapping as well as radiocarbon and paleomagnetic dating of more than 180 lava flows. They also understood changes in magma source components and found out that there is an abundance of picrite flow in the volcano’s southwest rift zone by conducting submersible studies.
6. Mount Merapi – Central Java, Indonesia
Background: Considered as the most active volcano in Indonesia, Mount Merapi has been erupting regularly since 1548. It was designated as one of the Decade Volcanoes because of its history of deadly eruptions and its risk to nearby populated areas. The latest eruptions happened as repeated outbursts during October to December 2010 and killed 353 people as a result of many pyroclastic flows.
Project achievement: Major collaborative projects such as geophysical monitoring were conducted by the Volcanological Survey of Indonesia and the German GFZ German Research Centre for Geosciences. Mount Merapi was actually the volcano studied in more international collaborations than any other decade volcano, with work continued by US, France, Japan, and New Zealand.
7. Mount Nyiragongo – North Kivu, Democratic Republic of Congo
Background: Since 1882, Mount Nyiragongo has erupted at least 34 times. The volcano contains a lava lake, which has been the most voluminous known lava lake in recent history. Together with the nearby Mount Nyamuragira, this volcano is responsible for 40% of Africa’s historical volcanic eruptions. The latest major eruption of Mount Nyiragongo happened in 2002, where 147 people died from loss of oxygen by carbon dioxide and buildings collapsing due to earthquakes and lava.
Project achievement: When the lava lake began to rise and threaten refugees from nearby Rwanda in 1994, the seismic, tilt, thermal and EDM monitoring were increased.
8. Mount Rainier – Washington, United States
Background: Mount Rainier is the highest mountain in Washington, and is one of the most dangerous volcanoes in the world. Because it can produce massive lahars that could threaten the entire Puyallup River valley and can affect the southern sections of the Seattle metropolitan area. Though the volcano is more considered as a mountain right now because of its dormancy, scientists say it is still alive. It has the greatest likelihood of causing great loss to lives and property if eruption would occur – with effect far greater than what Mount St. Helens did in its May 1980 eruption.
Project achievement: An acoustic early warning system has been developed for collapse events and lahars as part of the agreement between real-estate developers and public safety officials. A law has also been enacted for measures that need to be taken to mitigate disasters which could be caused by future eruptions. The United States Geological Survey (USGS) has produced an educational video entitled “Perilous Beauty – The Hidden Dangers of Mount Rainier.”
9. Sakurajima – Kagoshima, Japan
Background: The Sakurajima is a volcano formed within the Aira caldera as a result of an eruption some 22,000 years ago. In 1914, Sakurajima had a powerful eruption, in which the pre-eruption killed at least 35 people. Before the eruption, almost all residents have evacuated because of large earthquakes that served as a warning. Additional 23 people also died after the eruption.
Project achievement: In 1998, an Asian Active Volcano Summit was held. It became an avenue for sharing experiences during volcanic crises among scientists and local officials from the Philippines, Indonesia, Japan, and Italy.
10. Santa Maria – Quetzaltenango, Guatemala
Background: The Santa Maria Volcano is part of the Sierra Madre range of volcanoes that extend along the western edge of Guatemala. The volcano’s eruption in 1902 was one of the three largest eruptions of the 20th century after the 1912 Mount Novarupta and 1991 Mount Pinatubo eruptions. Because of its ability to create a large eruption and the threat it can pose to the nearby populations, it has been chosen as one of the Decade Volcanoes.
Project achievement: The village of El Palmar was evacuated in 1998 before it was destroyed by lahars. In 1993, a workshop focused on the volcano generated many new plans and much enthusiasm, but the higher levels of government did not support the project, causing only a few plans to be implemented.
11. Santorini – South Aegean, Greece
Background: The beautiful island of Santorini is what remained after the enormous Minoan eruption that destroyed the Eastern Mediterranean. Since 1969, intense and extensive archaeological excavations have been conducted, which brought to light the Cycladic town that has been buried beneath the Minoan ash layer. This eruption was one of the largest volcanic events in history.
Project achievement: Because of the Decade Volcano project, a modern network of telemetered seismometers, thermometers, tide gauges, and CO2 flux instruments were established. It also ushered the establishment of the Institute for the Study and Monitoring of Santorini Volcano (ISMOSAV), a non-profit organization focused on the monitoring of the volcano.
12. Taal Volcano – Batangas, Philippines
Background: The Taal Volcano is located on the Volcano Island near the middle of the Taal Lake, which partially fills Taal Caldera. It is the second most active volcano in the country with 33 recorded eruptions since 1572, and one of its most beautiful scenic views. The eruptions of the Taal Volcano in the past have caused loss of life of around 5,000 to 6,000 people. Though the volcano has been quiet since 1977, it showed signs of unrest since 1991. These reasons made this volcano worthy of close study to be designated as a Decade Volcano.
Project achievement: The project brought workshops for scientists and local leaders, as well as limitations on high-density housing developments in the Taal Caldera. They also established a broad stratigraphic framework and examined the sequence of activities within single eruptions.
13. Mount Teide – Canary Islands, Spain
Background: Mount Teide is not only an active volcano – it’s also the highest point in Spain. Its most recent eruption was a long time ago, in 1909, but it was violent and destructive, just as its other eruptions before that. Its designation as a Decade Volcano was decided by the United Nations Committee for Disaster Mitigation, because of its history and proximity to many large towns. Future predictions conclude that Teide will erupt violently in the future just like that of Vesuvius and Etna.
Project achievement: Mount Teide has been chosen as the location for a post-graduate international course on volcanology, sponsored by IAVCEI, UNESCO, and other organizations. The work in the volcano also produced laws on procedures for preparing and releasing volcanic hazards information.
14. Ulawun – West New Britain, Papua New Guinea
Background: In Papua New Guinea, one of the most active volcanoes is Ulawun, which is also the highest mountain in the Bismarck Archipelago. The first recorded eruption of the volcano happened in 1700, and since then, Ulawun erupted 22 times. Thousands of people live near the volcano, and that is why it has been listed as one of the Decade Volcanoes.
Project achievement: A workshop in 1998 established plans for improved seismic monitoring, a study of the stability of the volcano’s structure, and a hazard map that shows the common activity of Ulawun. However, these activities were scaled back and delayed by a massive civil service cutback in the country.
15. Mount Vesuvius – Campania, Italy
Background: Probably the most popular volcano on the list, Mount Vesuvius is best known for its eruption during 79 AD that led to the destruction and burying of the Roman cities of Pompeii and Herculaneum. This volcano erupted many times since then. Mount Vesuvius is considered one of the most dangerous volcanoes in the world due to its very violent tendencies that can affect a population of more than 3 million people.
Project achievement: The project led to the development of the first modern evacuation plan for parts of Naples and other vicinities that can be affected. The plan defined hazard zones, civil defense responses and scientific alert levels referenced to the eruption in 1631.
16. Mount Unzen – Nagasaki, Japan
Background: In Japan’s southernmost main island lies Mount Unzen, which caused Japan’s worst volcanic-related natural disaster – the 1792 lava dome collapse that triggered a mega-tsunami, claiming the lives of 14, 524 people. After being dormant for several hundred years, Mount Unzen violently erupted again in 1991, killing 43 people (three of whom were volcanologists).
Project achievement: Since the eruption at Mount Unzen happened shortly before it was chosen as a Decade Volcano, and it posed some difficulties for the program. However, the latest eruption from 1990-1995 was exceptionally well-documented, and many scientific lessons have been published. Scientists debated about whether the eruption that had ended led to a useful set of criteria for the project, but the results were later applied to Montserrat.