The Galapgos Island questions!! Help me please!?

Question

As the Galapagos islands erupted from the sea bed, being, volcanic, how would their origin affect the animal and plant life that has become established there?

oh, and what are the advantages of the tortises growing over 1.5m in length and weighing over 250kg???

Thanks =]

Answer 1

Arising in the sea has limited Galapagos life to those species that could either fly there or survive on driftwood long enough to float there e.g. iguanas. Many island creatures are abnormally big or small since there is less habitat or less competition--apparently the latter applies in the case of tortoises.

Answer 2

Volcanoes are the result of the tectonic movements of the Earth's crust, when magma from the entrails of the planet goes out as lava. They became present in the legends and mythology of all people living around them, which venerated and feared them at the same time.

There are submarine and terrestrial volcanoes, but those with an impact in human life are mostly terrestrial, a number of 1,500. These are encountered on the subduction zones (where a tectonic plaque falls under another) like on the Pacific Ring of Fire (from Kamchatka till Indonesia and western Americas, from Alaska to Chile) or on the oceanic mid-ridges (like in Iceland). Volcanologists classify eruptions, depending on their violence, on a scale from 0 to 8, called VEI (Volcanic Explosivity Index).

Amongst the hundreds of active or non-active volcanoes, here is a list that we should all know, about the most significant volcanoes on Earth. They are not aligned by size or importance.

1.The most important volcano in North America is Mount Saint Helens, located in Skamania County, Washington, in the Pacific Northwest region of the US, at 96 miles (154 km) south of the city of Seattle and 53 miles (85 km) northeast of Portland, Oregon. This active volcano is located in the Cascade Range and is part of the Cascade Volcanic Arc, a segment of the Pacific Ring of Fire that includes over 160 active volcanoes. St Helens is the fourth volcanic peak in the Cascade Range.

On May 18, 1980, its eruption, the deadliest and most economically destructive volcanic event in the history of the US, killed 57 people, even if it is considered minor when compared to others elsewhere on Earth. The explosion caused an earthquake with a magnitude of 5.1 on the Richter scale. A billion cubic meters of rocks, lava and debris were spread over an area of 500 square km. The gas and ash mushroom like column raised 27 km (17 mi) into the atmosphere. The mud layers was of 15 m (50 ft), and the debris layer at the base of the volcano varied between 45 to 200 m (150-666 ft). The ash cloud was blown to eastern Washington, where roads and streets were covered by a 7 cm (3 in) deep ash layer.

Life on a surface of 58,560 hectares was wiped out. The explosion killed 6,000 black tailed deer, 200 black bears, 14,000 coyotes, 11,000 rabbits, 300 lynxes, 15 pumas and 10 million trouts and salmons in the lakes turned into swamps. The destroyed wood could have been used for building 200,000 individual houses. The regeneration of the new forest will take a century. 8,000 km (5,000 mi) of roads were destroyed. When the 300o C lava reached the Spirit Lake, the vapors raised to 2 km (1.2 mi). The eruption was compared with the explosion of 27,000 atomic bombs.

The height of the volcano dropped from 2,950 m (9,830 ft) to 2,250 m (7,500 ft), as 389 m (1,296 ft) of the volcano fell into the Toutle Valley, after a slip of 15 mi (24 km). The new crater is 3 km (1.9 mi) for 1.5 km (0.9 mi) with a depth of 400 m (0.25 mi). By 1999, life was recovered in 50 % of the destroyed areas around the volcano.

The volcano erupted 20 times in the last 4,500 years, the most powerful blast being that from around 1,900 BC.

2.The most famous Alaskan volcano is Mount Katmai, on the Alaska Peninsula with a maximum elevation of 6,716 ft (2,047 m). The volcano has caused ten known fatalities due to gas exposure. Katmai caused the most Alaskan eruption in recorded history on June 6-9, 1912.

3.Popocatepetl ("Smoking Mountain" in the language of the Aztecs) is the most important volcano in Central America. This volcano had over 20 major eruptions since the arrival of the Spanish in 1519. It is only 70 km (40 mi) southeast of Mexico City, and even if still active, it is covered by glaciers. It is part of the "volcanic belt" of Mexico City, comprising also Pico de Orizaba or Citlatepetl ("The Mount of the Star") and Ixtacciahuatl ("White Woman"). It had over 20 major eruptions since the arrival of the Spanish in 1519.

Popocatépetl is 5,452 m (18,173 ft) tall, being covered by 3 glaciers on a surface of 7 square km. The crater is elliptical, 750-800 m (2,500-2,700 ft) wide and 250-300 m (85-100 ft) deep. Trees cover the volcano up to 4,000 m (13,300 ft). Aztecs ascended the volcano during their religious rituals.