Transcript File - Mr Raynes Geography

1886 Tarawera Eruption
• Soon after midnight on 10
June 1886, people of Kaikohe,
Auckland, New Plymouth,
Napier and Blenheim were
wakened by loud noises. They
thought cannons were being
fired from ships in distress
offshore. People in Rotorua
knew exactly what was
happening. They could see
fireworks blazing across the
summits of the three domeshaped hills we call Mount
Tarawera. The red glow was
also seen as far away as
Auckland. New Zealand was
experiencing its largest
eruption in over 800 years.
• Before 1886, the Rotorua
area was well known
overseas for its beautiful
scenery and thermal
attractions. The most
popular sites were the
Pink and White Terraces
by the shores of Lake
Rotomahana. The
terraces were very
popular and attracted the
first tourists to New
Zealand.
White Terraces
Pink Terraces
• Rotorua was the only settlement of any
size at the time and was where most
Europeans lived. There were many Maori
villages around the district. Te Wairoa was
the largest and also had a few European
homes, boarding houses, churches and a
school.
A Man and his
whare in Te Wairoa
prior to the eruption
• Te Wairoa was the base
for tourism for the Pink
and White terraces.
Tourists would trek from
Rotorua to Te Wairoa
where a Maori guide
would escort them to the
terraces to bathe.
• It was these people in Te
Wairoa who were first to
experience the eruption
of Tarawera on 10th June
1886.
What do you remember so far?
• On a map of the North Island locate the
places that heard the Tarawera eruption.
• Why was the area famous?
• What was the nearest town of significance
at the time of the Eruption?
• What was the name of the village that
catered for tourists in the area?
Processes that produce an ENE…
• Tarawera is part of the Otakaina Volcanic
zone which today we know as being a
product of Subduction of the IndoAustralian and the Pacific Plates. Mount
Tarawera’s eruption came as a surprise to
many people because it doesn’t look like a
volcano and it didn’t have any hot springs
or craters.
• Activity:
Draw a series of
sketches showing the
processes which
caused Mount
Tarawera to erupt.
Mount Tarawera
What people experienced on 10
June 1886
• 12.30am
Earthquakes start in Te Wairoa and Rotorua
• 12.30-2am Earthquakes become stronger and stronger
• 2.10am
After a very violent earthquake shock, a large eruption
cloud rises 9.5km above Mt Tarawera
• 2.30am
Magma erupts from craters across Tarawera’s three
summits and an eruption plume rises above Waimangu
to the south-west
• 3.20am
Lake Rotomahana begins to erupt explosively, causing
a massive eruption plume 11km high
• 3.30-6am
Eruptions and violent earthquakes continue along a 17
km line between Tarawera and Waimangu.
• 6am-12pm Eruptions stop but earthquakes continue. Eruption
clouds block out the sun and shower the land with mud
and ash.
• Before the eruption the crust under
Tarawera began to weaken. A fault line
opened up and energy-charged magma
began to rise. Mud pools and geysers
became more active and there were
frequent earthquakes. People noticed the
lakes seemed to be breathing. Lake
waters rose and fell, were warmer than
usual and had strange waves on calm
days.
A changed Landscape
• The Tarawera
eruption had a
dramatic impact of
landforms, water
features, native
vegetation and
thermal areas.
The landscape after the
eruption…
Landforms
• The most dramatic
changes were close
to Mount Tarawera. A
line if craters 17km
long had been blasted
across Mount
Tarawera, Lake
Rotomahana and the
Waimangu thermal
area.
• Other changes to the landscape included:
1) A temporary lake formed by a dam of ash and
rock
2) The steaming Rotomahana crater had a new
small hot-water lake
3) The Pink and White terraces were destroyed
4) Scoria, ash and mud lay up to 3m thick close
to the craters
5) Ash falls coated the north-eastern North Island
Vegetation and soil
• Native forests and
scrublands close to
Tarawera were burned by
fireballs and smothered
under meters of ash
• Soils were buried under
infertile layers of volcanic
ash which made it difficult
for plants to recover.
• The Tikitapu bush was
destroyed.
Water features
• Lakes and rivers were dammed and heavily
polluted with ash
• Massive drainage changes in Lake Rotomahana
Basin
• Rivers disappeared and new channels
developed
• Many new hot springs, boiling rivers, geysers
and mud pools appeared after the eruption and
existing ones because more active
• Activity:
Draw a sketch of Mount Tarawera and
annotate it with the effects the eruption
had on the land.
How the eruption affected people…
• In the first terrifying hours, people concentrated
on survival.
• Mr McRae, hotel keeper at Te Wairoa:
“A storm appeared to be coming on, and shortly after what seemed
to be heavy hailstones came pouring on the roof. This was
succeeded by heavy stones, fireballs and mud, the lava falling after
the manner of rain. The weight of these substances upon the room
soon began to tell upon it. The roof of the hotel gave way about half
past four am with a loud smash, and the whole of the upper storey
collapsed, the debris pouring into the rooms below. Te back part of
the house gave way next, and all of a sudden we heard a fearful
crash and roar as thousands of tons of stuff were falling, and we
heard the balcony come down. There was a terrific gale and the fiery
stones and mud still descended incessantly. Mr Brainbridge
remarked that he expected to be with his maker in an hour or so”.
• Explosions and
ground surges
destroyed Maori
villages at Moura and
Te Ariki. Other
villages near the
craters, like Te
Wairoa, were thickly
blanketed in ash.
The school house at
Te Wairoa
• 153 People had died
(everyone in Moura and Te
Ariki and a few people in Te
Wairoa). The death poll
would have been much
higher if it were during the
day when tourists were at the
Pink and White terraces.
• Te Wairoa village was almost
completely buried under 23m of ash. Many survived
because they sheltered in the
Guide Shoppe's large
strongly built whare.
The effects of the
eruption on the area
• Throughout the devastated region, the injured
were given emergency first aid. Many were
carried on stretches or horse-drawn carts to the
hospital and hotels in Rotorua.
• The dead were buried to prevent the spread of
disease
• The most urgent needs were clean water, food,
clothing and shelter. Unfortunately there was no
civil defense to co-ordinate relief efforts and no
easy way of getting help from other areas.
• A lot of badly injured people, visitors,
women and children left the area
immediately. Those who remained
organised themselves so as to get
essential jobs done. Emergency shelters
were erected, and donated goods were
distributed. Tracks were cleared,
Rainwater was collected.
• There were severe economic problems in a
region heavily dependant on tourists for wages
and incomes. The major attraction of the Pink
and White terraces were gone and the whole
lakes district was buried in mud. Most people
stayed away. Insurance did not cover ‘volcanic
eruptions’; most residents faced the very
expensive recovery stage without money. Many
were forced to leave the district. Repairs needed
to be made to the roads and bridges around the
area and timber was brought in to rebuild
houses, hotels and shops.