Mountains
of Fire
Volcanoes are the guardians of
nearly unimaginable forces that originate from deep
inside the Earth. For millions of years they have
been a force of destruction and creation, and have
also been a source of fascination for humans.
The complex beauty of these formations,
described by some as a pipeline system that transports
rock in its liquid state from dozens of kilometers
underground to the Earth's surface, have also won
a place on the Internet, where it is possible to study
them like never before - and undoubtedly with greater
safety…
One of the numerous websites
dedicated to volcanoes lists more than 1,500 of these
fiery mountains, and another informs us that more
than 500 of them are active.
Volcanoes exist on the Earth's
land surface as well as in the ocean depths. The study
of their activity, still a great mystery, is the work
of volcanologists, scientists who often run considerable
risks as they make their observations blasted by the
heat of lava.
The Internet provides the curious
with extensive portals
and directories,
sites dedicated to explaining
the ''anatomy'' of the volcano, lists of these formations
around the world, and even a registry of eruptions…
Portal:
Volcano World
Global
Volcanism Program
Current
Volcanic Eruptions
Latin
American Volcanoes
Directory:
Volcanoes.com
Weekly
Volcanic Activity Report
Volcano
Observatory
Volcanoes
Online
A
Threatening Void
One cannot just look at the sky
to locate the hole in the atmospheric ozone layer.
It is an invisible threat. The problem, produced by
the alteration of the Earth's environmental conditions
as a result of human activity, poses great dangers
for humanity and ecosystems.
The ozone hole is not really
a hole, but a thinning of the ozone layer that surrounds
our planet and serves to filter out harmful ultraviolet
rays. This thinning is concentrated in the Earth's
extreme south.
When this natural filter is reduced,
the Sun's rays reach the Earth's surface with greater
intensity and can cause biological changes that are
not yet fully understood. In the case of human beings,
and of some animal species, the harmful rays can lead
to skin or eye problems.
The ozone hole is oval-shaped
and its center is found some 900 km from the South
Pole. The phenomenon reaches its maximum - meaning
the thinned area is largest - during the Southern
Hemisphere spring, September to December, and affects
the residents of such southern cities as Chile's Punta
Arenas.
Experts on the ozone layer report
that at the hole can cover 24 million square km, but
has even reached 27 million square km.
The existence of the ozone hole
was first suggested by research in the 1970s. By the
mid-1980s, governments around the world signed the
Vienna
Convention to protect the ozone layer, and in
1987 it was proposed that all nations sign the Montreal
Protocol.
This Protocol calls for a ban
on the production of chlorofluorocarbons (CFCs) and
other compounds that are known to cause chemical reactions
that harm the ozone layer. CFCs are present in our
everyday lives, as they are used in the cooling systems
of refrigerators and in manufacturing aerosols.
The magnitude of this problem
is reflected in the proliferation of Internet sites
dedicated to the ozone layer, explaining
the phenomenon occurring up in the sky in simple terms
or in scientific
studies, official
documents or images.
UNEP:
Ozone Secretariat
UNEP:
Montreal Protocol
Document:
Action on Ozone 2000
Secretariat
for Implementation of Montreal Protocol
Vienna
Convention
Frequently
Asked Questions about the Ozone Layer
World
Meteorological Organization: Ozone Bulletin
Yahoo!:
News on the Ozone
NASA: Ozone Mapping
Ozone
Hole Tour
Greenpeace:
Ozone Crisis
FAQs:
Ozone Depletion
Slithering
Creatures
Snakes have slithered across
the surface of the Earth for millions of years. They
are part of the reptile group, primitive beings in
the evolution of life. They have always captivated
the imagination of humans, who give snakes a leading
role in various mythologies.
Snakes are members of the subgroup
''serpents'' and, according to scientific
classification, are divided among some 20 families
for a total of more than 2,900 species.
The most numerous family is the
colubridae, but the most remarkable are cobras, rattlesnakes,
or the enormous constrictors, like the anaconda.
Though serpents appear frequently
in our cultures and legends, they tend to be rejected
by our collective unconscious. Many people fear snakes
because some are truly very dangerous, capable of
biting and injecting their victims with deadly venom.
But there are those of the opposite
opinion, evident in the fact that most Internet
websites about snakes are maintained by people who
keep these creatures as pets. And they assert that
there are plenty of reasons to promote the peaceful
coexistence between snakes and humans.
Thesnake.org
Snakes
Snakebite
Emergency Information
Scientific
Classification
Rattlesnake
Museum
Anacondas:
Biggest Snakes
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