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Image showing the eruption of Pinatubo on June 12, 1991.

Giant Volcanic Eruptions
In this alternate explanation of the loss of the dinosaurs, they did not die out in an instant in some catastrophic disaster, but over a period of a few million years of very stressful conditions. These conditions were caused by a series of giant volcanic eruptions that lasted for a long time --several million years, in fact. Even in our time, large volcanic eruptions have been known to change our weather--mostly by dumping vast amounts of sulfur into the upper atmosphere. The sulfur changes into droplets of sulfuric acid which are bright and reflect away the light of the Sun before it reaches and warms Earth's surface. Consequently, the temperature on the surface of Earth drops somewhat. Even a relatively small eruption like that of Mount Pinatubo in the Philippines (pictured at the top of this page) put enough sulfur into the air to cause a measurable drop in temperature world-wide. Image: Eruption of Pinatubo on June 12, 1991. Image courtesy of NOAA National Data Center, NGDC.

Image of a graph that displays the Earth's average Global Surface Air Temperatures from 1950 to 2000.  Please have someone assist you with this.

This graph of the Earth's average temperature changes since 1950 shows many ups and downs, but the trend since about 1960 has been constantly upward. (Many people think that is the result of Global Warming, but that is another story!) Notice the big drop that lasted for about three years starting in 1991. That is the effect of the eruption of Pinatubo. The drop is only about half a degree, so most people didn't notice it. But this change was caused by only one fairly small volcanic eruption! Graph courtesy of Goddard Institute for Space Studies.

In 1815, a much larger eruption occurred at Tambora in Indonesia. This single volcano put enough sulfur into the air to cause several degrees of cooling. Enough to cause crop failures and starvation in France and northeastern United Stated in 1816 and 1817!

What happened to the dinosaurs? Imagine an endless series of super-Tamboras erupting every few decades or centuries. Remember, hot-spot eruptions are hundreds and thousands of times larger than even Tambora-size eruptions. The result would be irregular periods of great cold every few decades or centuries. Some scientists think that the eruptions poured enough carbon dioxide into the air to cause long-term warming, so that the weather would be alternating periods of unusually hot and cold weather. Plants in different areas of the land would die, not all at once, but during the long periods of poor weather. The excess carbon dioxide might also have poisoned the oceans, causing marine plants and animals to die. When the plants died, the local plant eaters like triceratops and brachiosaurus soon died also, followed by the meat eaters like T-Rex. Animals would be forced to migrate or die. And often they died anyway.

Eventually, the eruptions stopped and the weather returned to normal. But before that happened, many of the Earth's plants and animals, including the dinosaurs, were gone.

But now, the question is is there any evidence that this is how the dinosaurs died? There is an appropriately huge volcanic deposit that formed at the right time: the Deccan Traps in India. You might look up more information about volcanoes, the Deccan Traps, or "hot spot" volcanism. Or watch a volcano erupt. What about the fossil record? Did the dinosaur fossils end all at once, or do they slowly fade out over a period of time? Is there any evidence of climate change or stressed animals? There is much you can look for to test this alternate explanation. Good Luck!

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Thaaaar She Blows!
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Thaaaar She Blows! | Giant Volcanic Eruptions

Giant Impact | Super Nova | Disease | Volcanoes | Orbital Changes | Meet the Dinosaurs | Into the Future

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