Faculty Profile prashantha K EEE dept Sri Sairam college of Engineering
Geysers & volcanoes (José Jiménez)
1. Geysers & Volcanoes (Spain)
A quick but precise walkthrough.
José Jiménez Luna 2ºBach A
2. Tips before the start
1. Click any word you don’t know the meaning of and you will be
directed into a Thesaurus dictionary reference.
2. There will also be links to many YouTube optional videos. If an
internet connection is not available at that moment, I will include
those videos in a portable storage disk.
3. To make things easier to those not very familiarized with
science, explanations shall not be very hazardous to understand.
4. Copy & Paste is not used, you can simply check this by using
Google. Sources are shown at the end.
5. Effects will only be used only in those slides I consider to be
appropiate. If you want to disable background music, turn your
headphones/speakers off.
6. Learn & Enjoy.
3. Behavior of a volcano
A volcano can be defined as
any crater or opening in the
Earth's surface which allows
molten rock and volcanic gases
to escape from the inner layers
of the Earth.
Volcanoes are usually
mountainous in shape, but they
can appear in nearly any form,
like volcanic vents existing on
the ocean floor, ice volcanoes,
(Jupiter, Saturn and its moons),
and volcanoes that are simply a
crater in the ground.
I will show an example of each
one. Simple crater
5. Main volcano types
Every volcano has a different eruptive
history. However, we are able to clasify
them in three main types.
TYPE SHAPE COMPOSITION ERUPTION
Scoria Cone Basalt tephra,
occasionally
andesitic
Strombolian
Shield Volc. Basalt lava
flows
Hawaiian
Stratovolcano Variable Plinian
6. Lava composition
Generally, most lava is of basaltic
composition. Basaltic melts have
usually lower gas contents and are
very fluid.
Its lower density is due to their
lower SiO2 (silica) contents. When
gases are thrown/expelled from
basaltic melts they are allowed to
rise unimpeded through the fluid
magma without a significant build
up of gas pressure. This results in
relatively calm, nonexplosive
eruptions, and a preponderance of
lava.
How Volcanoes Work - Optional Video
7. Lava composition (2)
A) Pahoehoe Lava: typically the
first to erupt from a vent. They
are relatively thin (1-2 m) and
very fluid. No viscosities.
Pahoehoe is often converted to
a'a lava as it advances
downslope, away from the
volcano.
There also lavas with unusual
composition, like andresite, dacite ot
carbonatites although these are less
common
B) A’a Lava: these lava flows
are often more viscous, and
typically thicker, than pahoehoe
lavas they tend to advance at
greater rates. Their flow fronts
can vary from two meters to as
much as twenty meters thick
Basaltic lava can be classified into two subtypes:
8. Eruption Types
Although eruption types depend
greatly on the magma composition,
we are able to clasify them.
a) Fissure erup: fissure eruptions
are generated at several
contemporaneous sites along a linear
fracture, or along an echelon.
b) Hawaiian erup: calmest of the
eruption types. They are characterized by
the effusive emission of highly fluid basalt
lavas with low gas contents
9. Eruption types (2)
c) Strombolian erup: short-lived,
explosive outbursts of pasty lava ejected
a few tens or hundreds of meters into the
air.
d) Vulcanian erup: most often
associated with andesitic to dacitic
magma. The high viscosity of these
magmas makes it difficult for the
vesiculating gases to escape
e) Plinian erup: associated with
volatile-rich dacitic to rhyolitic lava,
which typically erupts from
stratovolcanoes.
f) Hydrovolcanic
eruptions :generated by
the intereaction of magma
with groundwater.
10. Geysers
A geyser is a vent in Earth's surface
that periodically ejects a column of hot
water and steam (gas). Even a small
geyser is an amazing phenomenon;
however some geysers have eruptions
that blast thousands of gallons of boiling
hot water up to a few hundred feet in
the air.
There are certains conditions required
to form a geyser:
A) Hot rocks below (or even lava)
B) Subterranean water source
C) A wide fissure.
D) An ample ground water source
There are no active famous geysers in
Spain. However there is an artificial one
in Timanfaya Park (Lanzarote). Here is
a video demonstration.
11. Spanish Eruptions
There are several zones with
volcanic activity in Spain. These
are not always in the peninsula
itself, but in the Canary Islands.
However, we can find some in
the peninsula, like La Garrotxa
(Gerona), Cabo de Gata
(Almería), Cofrentes (Valencia),
y Campos de Calatrava (Ciudad
Real).
Landscape changes due to Chinyero vulcano
eruption in Tenerife (1909) - Optional Video
Calatrava Volcanoes – Optional Video
12. Last eruption (1971)
Was the shortest eruption ever recorded in the
history of the Canary Islands, considering the one
that happened in the XVIII century, which lasted
about 6 years
There have always been eruptions (16 recorded) in
the Canary Islands zone, none with mortal victims.
This was only possible due to the low demographic
density and the fluency of the lava emitted by the
volcanoes.
The volcano caused material damages, it
destroyed vine cultivation zones and
destroyed a beach, although another was
formed thanks to the corrosive power of
the lava.
It didn’t affect high density zones thanks to
the proximity of the beach. The lava
poured to the sea was solified, making the
island grow in size.
13. Speculation
According to Ramón Ortiz, vulcanologist and
researcher from the CSIC: “An eruption can
occur unexpectedly at any time in any
volcanic zone of the peninsula itself or the
Canary Islands. In Latin America or Africa, an
annual eruption is common, but not in
Europe; that is why people tend to think
there is no vulcanic activity in Europe.
However, there have been 4 eruptions in
Tenerife in the last 100 years.”
Recent investigations have shown that the
eruption of certain volcanoes in Europe might
have caused the dissappearance of the Homo
Nehanderthalis. Nevertheless it didn’t
extinguish those inhabiting Africa and Asia
zones.
14. Speculation (2)
Regarding geological issues, the Canary
archipelago would have been about 10 times
bigger 60 million years ago than it is
nowadays. According to Fernández Palacios,
Geology professor and reasearcher from
Masachussets MIT, there could be many other
islands hidden hundreds of meters under the
sea.
The islands we know today are only a
fraction of what they used to be.
Fuerteventura emerged 20 million years
ago, Gran Canaria 15mill, Tenerife 11mil
ago, and Fuerteventura 1mill ago.
Several technological improvements have
achieved to chart the sea bottoms under
the archipelago and the island of Madeira
Many mountains and hills were discovered
under sea thanks to these techniques