Volcanic landforms are formed by volcanic activity and include features like volcanoes. Cinder cones are small cones formed from strombolian eruptions consisting of basaltic to andesitic material. Shield volcanoes have gentle upper slopes and steeper lower slopes formed by low-viscosity basaltic lava flows. Stratovolcanoes have steeper slopes than shield volcanoes due to layers of lava and pyroclastic material. Calderas are large depressions formed by collapse of volcanic structures. Artificial islands are human-made landforms constructed rather than formed naturally.

1. VOLCANIC LANDFORMS
These landforms are formed as a result of volcanic
activity, or else they represent the various kinds of
volcanoes and volcanic features themselves.

2. OVERVIEW…

3. CINDER CONES
(TEPHRA CONES)
 Cinder cones internal layered structure due to varying
They show an are small volume cones consisting mainly
of tephra that resultafrom strombolian eruptions. They
On young cones, depression at the top of the
intensities of the explosions that deposit different
usuallycalled a of basaltic to andesitic material.
cone, consist crater, is evident, and represents the
sizes of pyroclastics. controlled by the angle of
Slopes of the cones are
area above the vent from which material was
repose (angle of stable slope for loose unconsolidated
material) and ejected.
explosively are usually between about 25 and 35o.

4. Cinder and tephra cones usually occur around summit
vents and flank vents of stratovolcanoes.
Parícutin Volcano in Mexico. This volcano was born in
a farmers corn field in 1943 and erupted for the next 9
years.
Last eruption:1952

5. VOLCANIC DOMES (LAVA DOMES)
resultfrom the extrusion of highly viscous, gas poor
andesitic and rhyolitic lava.
Blocks of nearly solid lava break off the outer surface of
the dome and roll down its flanks to form a breccia
around the margins of domes.

6.  Most dome eruptions are
preceded by explosive
eruptions of more gas rich
magma, producing a tephra
cone into which the dome is
extruded.
 They form unstable slopes
that may collapse to expose
gas-rich viscous magma to
atmospheric pressure.
 This can result in lateral
blasts or Pelean type
pyroclastic flow (nuée
ardentes) eruptions.

7. SHIELD VOLCANOES
by gentle upper slopes (about 5o) and
Characterized
somewhat steeper lower slopes (about 10o)
Most shields were formed by low viscosity basaltic magma
that flows easily down slope away from the summit vent

8.  Vents for most shield
volcanoes are central vents,
which are circular vents
near the summit.
 Hawaiian shield volcanoes
also have flank vents, which
radiate from the summit and
take the form of en-echelon
fractures or fissures, called
rift zones, from which lava
flows are released.

9. The term 'en echelon'
refers to closely-spaced,
parallel or sub-parallel,
overlapping or step-like
minor structural features in
rock (faults, tension
fractures), which
lie oblique to the overall
structural trend.

10. The three main volcanoes which
make up the island of Hawaii:
Mauna Loa
Mauna Kea
Kilauea
Mauna Loa - largest landform on Earth

11. STRATOVOLCANOES
(COMPOSITE VOLCANOES)
Stratovolcanoes show than shield volcanoes, with
Have steeper slopes inter-layering of lava flows
sometimes have a crater at the summit that is formed
and pyroclastic material, which is why they are the top
o o
slopes of 6 to ejection on material from 30central vent
by explosive 10 low of the flanks to a near
sometimes called composite volcanoes.

12. Mayon Volcano
it holds the record of the world's
most perfect volcanic cone.

13. MAAR
result from phreatic or phreatomagmatic activity, wherein
magma heats up groundwater, pressure builds as the water
to turns to steam, and then the water and preexisting rock
are blasted out of the ground to form a tephra cone with
gentle slopes.

14. CRATERS AND CALDERAS
 Craters are circular depressions, usually less than 1 km
in diameter, that form as a result of explosions that emit
gases and tephra.
 Calderas are much larger depressions, circular to
elliptical in shape, with diameters ranging from 1 km to
50 km. Calderas form as a result of collapse of a
volcanic structure.

15. Formation of the
Crater Lake Caldera in
Eruptions of ash and pumice
Southern Oregon Caldera collapse
Today Steam explosions

16. CALDERA…

17.  Crater Lake Caldera in southern Oregon is an 8 km
diameter caldera containing a lake.

18. SLOPE LANDFORMS
Slope Development
 Landforms and landscapes change over time as
a result of various dynamic factors. These
factors include tectonic movement, weather,
erosion, and gravity.

19. BUTTE
 a prominent isolated hill with steep,
often vertical sides and a small,
relatively flat top

20. MESA
 A (Spanish and Portuguese for "table") is the American
 Formed by weathering and erosion of horizontally
English term for tableland, an elevated area of land with a
layered rocks that have been uplifted
flat top and sides that are usually steep cliffs.
by tectonic activity.
 In Spanish such a landform is more usually known as a
meseta.

21. PLATEAU
another landform that is relatively level, and some sources claim that a
plateau is an elevated plain.
A plateau has at least one steep, cliff-like side. It forms as a result of
geologic uplift (the slow upward movement of large parts of stable
areas of Earth's crust due to heat forces within the planet) or as a
result of much lava flows that spread out over hundreds of thousands
of square miles.

22. CLIFFS
usually formed by rock that is
a significant vertical, or near resistant rock exposure.
vertical,
to erosion and weathering.
are formed as erosion landforms due to the
 Sedimentary rocks are most likely that produce
processes of erosion and weatheringto
them.form sandstone, limestone, chalk, and dolomite.
 Igneous rocks, such as granite and basalt also often
form cliffs.

23. ARTIFICIAL LANDFORMS
 An artificial island or man-made island that has been
constructed by people rather than formed by natural
means.

24. YAS MARINA ISLAND
is an artificial island in Abu Dhabi, UAE near
natural Sir Bani Yas island.

25. THE PALM JEBEL ALI
is an artificial archipelago in Dubai, United Arab
Emirates which began construction in October
2002, was originally planned to be completed by
mid 2008 and has been on hold since

26. HARBOR ISLAND
is an artificial island in the mouth of Seattle,
Washington's Duwamish Waterway where it
empties into Elliott Bay.
was then the largest artificial island in the world,
at 350 acres (1.4 km²).

27. THANK YOU!!!