Volcanology is the study of volcanoes, lava, magma, and related geological phenomena. A volcano forms when magma rises from deep in the Earth's mantle and erupts on the surface. As more magma rises, it forms a magma chamber and conduit leading to a vent. Eruptions through the vent build the volcano over time. There are four main types of volcanism related to mid-ocean ridges, subduction zones, hotspots, and flood volcanism. Heat sources for volcanism include radioactive decay, accretion during planetary formation, tidal effects, and core formation deep within the Earth.

1. Introduction toIntroduction to
VolcanologyVolcanology
May 2008May 2008
Chapter 1

2. ContentContent
1.- Volcano.
Concept.
Origin.
Parts.
Earthquakes, tsunamis and volcanoes.
Volcanology.
2.-Volcanism.
Concept.
Types.
Heat source.
Isotopes.
Accretional heating.
Tidal heating.
Core formation.
Meteorits.

3. VOLCANOVOLCANO

4. VolcanoVolcano
An opening in the earth’s surface
through which lava, hot gases, and
rock fragments erupt.

5. Origin of VolcanosOrigin of Volcanos
1.- Magma 50-100 miles below the earth’s surface slowly
begins to rise to the surface.
2.- As the magma rises it melts gaps in the surrounding rock.
3.- As more magma rises a large reservoir forms as close as 2
miles below the surface (magma chamber)
4.- Pressure from the surrounding rock causes the magma to
blast or melt a conduit (channel) to the surface where
magma erupts onto the surface through a vent (opening).
5.- The magma, now called lava, builds up at the vent forming a
volcano.
6.- Often the volcano sides will be higher than the vent
forming a depression called a crater

6. VolcanoVolcano
Mount Saint Helen Eruption, May 18th 1980

7. Magma chamber
conduit
mantle
Parasitic Cone
Ash Cloud/Gases Vent
Lava Flow
Crater
Parts of a VolcanoParts of a Volcano

8. ““Ring of Fire”Ring of Fire”
Volcanic arcs and oceanic trenches partly encircling the
Pacific Basin form the so-called , a zone of frequent
earthquakes and volcanic eruptions.

9. Volcanoes and earthquakes
The distribution of earthquakes provides information about
magma pathways and the structure of volcanoes and they also can
have a lot to do with generating tsunami. Any time that you can
somehow displace a large amount of ocean water you generate a
large wave or group of waves that goes rushing across the ocean
at great speed.

10. VolcanologyVolcanology
Volcanology (also spelled
vulcanology) is the branch of
geology that studies volcanoes,
lava, magma and related geological
phenomena.

11. VOLCANISMVOLCANISM

12. VolcanismVolcanism
Volcanism is part of the
process of bringing material
from the deep interior of a
planet and spilling it forth on
the surface. In many cases,
eruptions build up a
piled of material, a mountain
what is called volcano.

13. Origin of VolcanismOrigin of Volcanism
There are four types of volcanism:
- Related with midocean ridges.
- Related with subduction zones
- Related with Hotspots
- Related with flood volcanism

14. Heat SourceHeat Source
The heat from a volcano
comes from deep within the
earth. Many miles
underground, the earth is
hot. Rocks beneath the
earth are so hot they turn
into a liquid called lava.
When a volcano erupts, the steam and ash is caused by lava
that is forcing its way toward the surface of the earth.

15. IsotopesIsotopes
Isotopes are any of the
different forms of an element
each having different atomic
mass (mass number). Isotopes
of an element have nuclei with
the same number of protons
(the same atomic number) but
different numbers of neutrons.
Therefore, isotopes have different mass numbers, which give the
total number of nucleons—the number of protons plus neutrons.
Hydrogen
Deiterium
Tritium

16. UU235 –235 – UU238238
U235 is an isotope of uranium that
differs from the element's other
common isotope, uranium-238, by
its ability to cause a rapidly
expanding fission chain reaction,
i.e., it is fissile. It is the only
fissile isotope found in any
economic quantity in nature. It was
discovered in 1935 by Arthur
Jeffrey.
U238 is the most common isotope of uranium
found in nature. In a nuclear reactor, it can be
used to breed plutonium-239, which itself can be
used in a nuclear weapon or as a reactor fuel
source.

17. ThTh232232 – K– K4040
Thorium is found in small amounts in
most rocks and soils. Th232 is used
in combination with a fissile nuclide
as a fuel source in types of nuclear
reactors known as breeder reactors.
Breeder reactors are able to
continually generate new fuel as fuel
is being consumed.
K40, which has a radioactive half-life of
about 1.2 billion years, could be an important
source of heat in the Earth’s core but this
has never been unambiguously confirmed in an
experiment.

18. Accretional HeatingAccretional Heating
The heating of bodies orbiting a star due to bombardment by
smaller objects . Accretional heating in forming planets results
from the transfer of kinetic energy of objects striking the
proto - planet surface.
By accounting for all energy transfer
for every cratering event it is
theoretically possible to determine the
thermal state of newly- formed planets

19. Tidal HeatingTidal Heating
In some other planents
is too small to have left
over accretional heat,
and radioactive decay
could not generate the
tremendous energy
required to power all of
the volcanic activity that
exists on the moon.

20. Core FormationCore Formation
Extensive melting of the earth as a result of giant impacts,
accretion, or the presence of a dense blanketing atmosphere is
thought to have led to the formation of the core. Collision
between a planet- sized body and the earth may have also
produced the moon.
Near the end of accretion, core
formation evidently ceased as upper
mantle conditions became oxidizing. The
accumulation of the oceans is a
consequence of the change to oxidizing
conditions.

21. MeteoritsMeteorits
Chondrites are stony
meteorites that have not
been modified due to
melting or differentiation
of the parent body. They
formed when various
types of dust and small
grains that were present
in the early solar system
accreted to form
primitive asteroids