Updated information Hunga Volcano impact in the Pacific - Photo: NOAA - The Pacific Community

Photo: NOAA

Updated information
Hunga Volcano impact
    in the Pacific

Could the volcano erupt again?
   Monitoring data over the past few days has not shown any
   signs of ongoing eruptions, but the risk of further eruptions
   is a very real possibility.
   It is important that people are aware of the possibility for
   further eruptions and tsunamis associated with Hunga
   volcano and monitor up-to-date information from relevant
   National Authorities.

Photo: RNZ

What could the volcano do next?
Experts are currently considering two main scenarios for
future volcanic activity:
   The volcano will settle down as the magma is exhausted
   after the 15th January eruption; or
   New magma will arrive to replace the initial magma that
   erupted. This would mean further eruptions, including the
   potential for tsunamis, but further activity is unlikely to
   be as violent as the most recent event.

                                              Photo: Tonga Geological Services

Is there a risk of another tsunami?
Yes. There is potential for further tsunamis, particularly if future
eruptions occur. Professor Cronin explained “if new eruptions
create sonic booms or shock waves through the air, particularly
in areas impacted by the previous tsunami, it’s wise to go to
higher ground, and for the time being these could be the best
early warning signals of tsunami generated by the volcano.”

Please keep informed on warnings from your local emergency
service agencies.

Twitter @sakakimoanau

Is food safe to eat if affected by
ash or acid rain?
Plants can be impacted by volcanic ash and to a lesser extent by acid
rain, however these impacts are due to exposure to acidity rather
than toxins. Green leafy crops may be burned by ash and acid rain,
whereas the roots of crops such as taro, cassava, yams and kumara
won’t be affected and will be safe to eat even if the leaves get burned.
Fruit with heavy skins, such as bananas, are also safe to eat when
peeled. Affected leafy vegetables are normally also safe to eat if
effectively washed, but this may not always be a practical option.

Is rainwater affected by ash and
acid rain?
The main impact on harvested rainwater water associated with ash is
the fine particles, which need to be allowed to settle and not stirred up.

Affected rainwater won’t be poisonous to drink but may taste slightly
metallic because of extra salts from ash and acid rain.
Despite the taste impacts, collected rainwater will be still safe to drink
over the short term and shouldn’t be wasted unless there is an
abundance of alternative supplies.

Is groundwater affected by
volcanic ash and acid rain?
Groundwater is generally very resilient to the impacts of ash and acid
rain, as soils are very good at filtering substances of concern. Even
shallow bores are usually very safe from impacts, as has been
demonstrated in Vanuatu after previous volcanic activity.

However, groundwater near coastal areas can be impacted by
saltwater inundation associated with tsunamis, and the operation of
pumps and power supplies needed to access groundwater can also be
impaired by ash and salt-water inundation.

What can communities do to protect
rainwater systems from falling ash?

If communities know there is an ash fall starting to occur and
have a roof-fed water supply, valuable water supplies can be
protected by temporarily disconnecting the pipe from the tank
while ash is falling. Water in the tank will be safe if the tank is
covered. When the roof has been flushed with rain, the tank can
be safely reconnected.

Is it safe to eat fish after this
eruption and tsunami?
Broadly, marine life will be unaffected. Professor Cronin said
“Instantaneous fish deaths can occur close to the volcano and in
places where large amounts of ash has entered the ocean. This is
because of acidity and sharp small particles that can kill marine
life. Fish floating that have died because of this should not be
eaten - not so much because of the ash but the decay that occurs
on the surface of water.”

“If fish are healthy, then there is no problem at all in
consuming them as usual. Marine life is quite resilient to these
events,” he explained.

 Photo: SPC Yellowfin Tuna

How big is Hunga Tonga Volcano?
The Hunga Tonga Volcano is around 1800meters high and 20kilometres
wide. That’s around 18 rugby fields high and 200 rugby fields across.The
Hunga Tonga- Hunga Ha’apai islands, which rose about 100meters
above the ocean before the recent eruption, is just the tip of this much
larger underwater volcano.
The 15th of December eruption radically changed the top of the
Hunga volcano, including the Hunga Tonga - Hunga Ha'apai islands.

                                                  Photo: Reuters

Recent history of eruptions?
Two moderate sized eruptions occurred over the past month.
The first occurred on 20th December 2021 and the second on
13th January 2022. Then a third much larger eruption (a 1 in
1,000-year event) occurred on Saturday 15th January 2022.
This latest eruption triggered a tsunami and generated a 30km
high plume of ash and gases, with approximately 400,000 tonnes
of sulphur dioxide released into the air. The eruption radically
changed the top of the Hunga volcano.

                                              Photo: Tonga Geological Services

What to do next?
   Stay in touch and informed on
emergency information and warnings
    from your local and national
   emergency service networks.