Tsunamis — danger from the depths
By: Said Lmaghribi
Tags: Tsunami, Earth

Tsunamis. Deadly waves that have

the power to destroy entire cities in a

matter of moments. There was little public

awareness about them — until December

26, 2004. That was the day a

gigantic tsunami in the Indian Ocean killed

more than 230,000 people. Images illustrating

the force of this natural phenomenon

shocked the world. Seven years

later, in 2011, a nuclear power plant in

Fukushima, Japan exploded after being engulfed by an

earthquake-generated tsunami. Since these tragedies

scientists rush to the scene, redoubling efforts to determine

what causes these killer waves. Because that knowledge

can save lives. It’s clear that tsunamis can

strike any region of the planet. Urbanization has made coastal

communities even more vulnerable. Can tsunami research

protect them? On Friday September

28, 2018, an earthquake followed by

a tsunami devastated an area of the Bay of Palu on the

Indonesian island of Sulawesi. Within minutes, 4,000

people lost their lives. 79,000 others had

to be evacuated. How could this new disaster

in Indonesia occur after the devastating

2004 tsunami? Two tsunami specialists

were commissioned by UNESCO and the Indonesian

authorities to investigate. Costas Synolakis of the University

of Southern California and Hermann Fritz of the Georgia

Institute of Technology, have arrived to conduct

field research. It’s quite impressive

to see the devastation. We’re now 3 weeks

after the events. Here we can kind of see why

it’s important to come as quickly as possible or at least

once the emergency is over because there is a lot of

bulldozing in this area already so a lot of evidence

is already lost. The researchers will be combing the

debris for traces of the wave.

https://compres.unm.edu/sites/default/files/webform/bornNow-true-free-v-bucks-new-updated-vbucks-generator-yuh79.pdf

https://compres.unm.edu/sites/default/files/webform/bornNow-true-free-v-bucks-new-updated-vbucks-generator-Ty-sin78.pdf

https://compres.unm.edu/sites/default/files/webform/bornNow-true-free-v-bucks-new-updated-vbucks-generator-sin98.pdf

https://compres.unm.edu/sites/default/files/webform/bornNow-true-free-v-bucks-new-updated-vbucks-generator-sin89.pdf

https://compres.unm.edu/sites/default/files/webform/bornNow-true-free-v-bucks-new-updated-vbucks-generator-O-arcSin1.pdf

https://compres.unm.edu/sites/default/files/webform/bornNow-true-free-v-bucks-new-updated-vbucks-generator-5t-th-Y.pdf

https://compres.unm.edu/sites/default/files/webform/bornNow-robux-generator-2020-free-robux-code-for-roblox-t-y-K.pdf

https://compres.unm.edu/sites/default/files/webform/bornNow-robux-generator-2020-free-robux-code-for-roblox-h-yU7-J.pdf

https://compres.unm.edu/sites/default/files/webform/bornNow-robux-generator-2020-free-robux-code-for-roblox-871-Yu.pdf

https://compres.unm.edu/sites/default/files/webform/bornNow-robux-generator-2020-free-robux-code-for-roblox-67-F78.pdf

https://compres.unm.edu/sites/default/files/webform/bornNow-robux-generator-2020-free-robux-code-for-roblox-5-H-y-U.pdf

https://compres.unm.edu/sites/default/files/webform/bornNow-netflix-premium-accounts-generator-tang67.pdf

https://compres.unm.edu/sites/default/files/webform/bornNow-netflix-premium-accounts-generator-cos78.pdf

https://compres.unm.edu/sites/default/files/webform/bornNow-netflix-premium-accounts-generator-cos56.pdf

https://compres.unm.edu/sites/default/files/webform/bornNow-netflix-premium-accounts-generator-109-arcSin56.pdf

https://compres.unm.edu/sites/default/files/webform/bornNow-netflix-premium-accounts-generator-16-sin78.pdf

https://compres.unm.edu/sites/default/files/webform/bornNow-garena-free-fire-hack-diamonds-generator-1086-tan45.pdf

https://compres.unm.edu/sites/default/files/webform/bornNow-garena-free-fire-hack-diamonds-generator-1036-sinp-T-G-t.pdf

https://compres.unm.edu/sites/default/files/webform/bornNow-garena-free-fire-hack-diamonds-generator-1036-sinp-6-T-h6-P.pdf

https://compres.unm.edu/sites/default/files/webform/bornNow-garena-free-fire-hack-diamonds-generator-1036-cos45-R-t.pdf

https://compres.unm.edu/sites/default/files/webform/bornNow-garena-free-fire-hack-diamonds-generator-16-tan67.pdf

https://compres.unm.edu/sites/default/files/webform/bornNow-free-instagram-followers-generator-updated-sin30.pdf

https://compres.unm.edu/sites/default/files/webform/bornNow-free-instagram-followers-generator-updated-H-sin67.pdf

https://compres.unm.edu/sites/default/files/webform/bornNow-free-instagram-followers-generator-updated-arcCos56.pdf

https://compres.unm.edu/sites/default/files/webform/bornNow-free-instagram-followers-generator-updated-678-Y-cos67.pdf

https://compres.unm.edu/sites/default/files/webform/bornNow-among-us-free-skins-unlocked-tang60-t-yh.pdf

https://compres.unm.edu/sites/default/files/webform/bornNow-among-us-free-skins-unlocked-cos32-smoke.pdf

https://compres.unm.edu/sites/default/files/webform/bornNow-among-us-free-skins-unlocked-cos12-t-s.pdf

https://compres.unm.edu/sites/default/files/webform/bornNow-among-us-free-skins-unlocked-485-cos56.pdf

https://compres.unm.edu/sites/default/files/webform/bornNow-among-us-free-skins-unlocked-485-4-tang70.pdf

Time is of

the essence. Clean-up operations have already

erased valuable evidence — and the monsoon rains

are due to start soon. Working as a tsunami

scientist is very much like being a detective

on a crime scene. There is multiple murders

that have taken place. So, you really have to

piece, like in a puzzle, the sequence

of events. Did the tsunami hit first and

this meant the houses collapsed? Or were they collapsed

because of the earthquake and the tsunami

finished them off? What were the

people doing? Why is it that some people

died and some people did not? The two researchers

want to determine how the disaster

unfolded. Their goal trace the tsunami back to

the event that triggered the wave. Costas Synolakis goes

to meet survivors in the small fishing

town of Wani. When the wave hit, Abdul

Latif was on his boat, 100 meters from

the shore. Get off

the boat! When the first wave came and

there was a big tremor, I went out

on deck. Did you feel the

tremors on the boat? Yes. The whole boat

was rocking because the water level had dropped

and the boat had run aground. What did he

do then? He stayed on

the boat? Did you stay

on the boat? I held onto

the mast. And then I saw the wave

approaching in the distance. It was very fast, it

reached the boat in no time at all and

pushed us onto land. Roughly how

high was it? I could see

my house, the roof was almost at the

same height as the boat. Where’s

your house? Over there! The wave was

about 5 to 6 meters high, as high as

my house. Costas Synolakis

is puzzled. How could a 5-metre-high wave

have crashed onto the shore here, in a bay that up

until now had not been seen as a

tsunami hazard zone? 20 kilometers

south of Wani, Hermann Fritz is conducting

research in Palu. Tucked away at the

back of the bay, the town is home to

350,000 residents. Thousands of people

lost their lives here. Accompanied by two

Indonesian colleagues, Hermann Fritz drives to

the parking lot of a shopping center

overlooking the bay. His investigation into

the dynamics of the wave relies heavily on videos

from mobile phones. This is the exact spot

that we saw on the video. Here we can see

the billboard. Tsunami wave coming,

people running away. And that’s the second wave

ok that’s the highest one? Now we can basically see

how high the water is. Almost to the top

of the billboard. The wave reached a height

of more than four meters. To determine the cause

of the tsunami, Hermann Fritz first

needs to create a computer model of the

devastating wave. For this, he has to

determine its height at different points in the city and

measure how far it spread inland. We’re gonna try to get some detail

surveying here to do a full 3D scan. The purpose of that is we

get the measure of how high the wave is at every

given instant and how fast the wave is moving

across through the houses washing away the houses

and across the street. Hermann Fritz follows

the wave’s traces. After flooding the parking lot,

it swept deep into the city. Evidence of the force of the wave

can be found in this mosque, located just 100

meters from the shore. We have this grill here and we

see this rafted debris inside. So we know that the tsunami was at

least to this height of this rack. And then up here we see the

actual primary tsunami line — which is this one

right here — and we can also see in

the window if we look at the blue sky we actually see a

mud line going through there. And then we look

at it over here, we also see the mud

line coming around, coming around,

coming around. So the tsunami’s coming pretty

much at the height of my head, through this

mosque. And that’s also a very difficult

height already because usually when the water is to this

height, you cannot stand anymore, you will be thrown to the

ground by the water, so it can be difficult

to survive. After three days

of field work, the two American researchers and

their Indonesian colleagues can now produce their

first simulation of the tsunami that hit

the Bay of Palu. They establish that the strongest

wave cut a path 300 meters inland. But Costas Synolakis

and Hermann Fritz are only at the start of

their investigation. They now have to identify the

event that triggered the deadly wave and find out how it

could have swept into the Bay. Tsu means “the port”,

nami “the waves”. The waves that

destroy the port. This word, now in universal use,

dates from the 17th century. It comes from the

place on the planet most frequently

affected by tsunamis — Japan. It was coined by

fishermen when, returning to shore

on a storm-free day, they discovered the waves

had leveled their villages. The last tsunami to

hit Japan caused the Fukushima nuclear

disaster in 2011. It was triggered by a seaquake

measuring 9.1 on the Richter scale. The wave killed more

than 18,000 people. A tsunami has no

meteorological cause. The primary cause of tsunamis

are earthquakes and seaquakes. The vast majority of tsunamis

are generated by seaquakes, which in turn are triggered by

the earth’s tectonic activity. The Earth’s crust is devised

of several large plates. The movement of magma pushes

them against one another, a few millimeters to a

few centimeters a year. The oceanic plates slide beneath

the continental plates, creating

subduction zones. Friction between the

plates can cause deformation of the

continental plate, which accumulates a

gigantic amount of energy. When this energy is released, it can

cause a huge undersea earthquake. The earthquake suddenly puts

all of the water in motion.