Continental Drift New Theory Wegener could not explain how they moved. New theory of plate tectonics

Plate Tectonics A plate is one of numerous rigid sections of the lithosphere that move as a unit over the material of the asthenosphere.

9.2 Plate Tectonics Types of Plate Boundaries  Divergent boundaries (also called spreading centers) are the place where two plates move apart.  Convergent boundaries form where two plates move together.  Transform fault boundaries are margins where two plates grind past each other without the production or destruction of the lithosphere.

Spreading Center

Oceanic-Continental Convergent Boundary

Oceanic-Continental Convergent Boundary

Oceanic-Continental Convergent Boundary

Collision of India and Asia

Transform Fault

LEQ #4 Why are trees, volcanoes and ice key to our understanding of earth’s history?

Let’s start with volcanoes…

Get ready for your mind to be… BLOWN!

The Earth actually gets COLDER after big volcanic eruptions!

How do volcanic eruptions effect the Earth’s temp? 1. Dust, ash, glass, and rock are released into the air during a volcanic eruption.

2. These things block the sun from reaching earth!

Clouds of ash can cover entire continents! In 2010, the Icelandic volcano Eyjafjallajokull erupted, spewing thousands of tons of ash into the air. 95,000 European flights were cancelled as a result of the eruption!

What information do Ice Cores & Tree Rings tell us? -Tell us how the CLIMATE has changed over time

Ice core- a sample of ice and snow that have built up over thousands of years -tell the amount of gasses in Earth’s atmosphere over time. Why do we care about ice?

What do ice cores tell us about the climate? Black or brown coloring- VOLCANIC ERUPTION (color caused by the ash) Yellowish color- Pollution in the air Bubbles- Carbon Dioxide (CO2) is in the air (lots of bubbles means that is was HOT!) NO MORE NOTES AFTER THIS!!!

Why do we care about trees? Tree Rings: tell the amount of rain over time -Big Rings- A LOT OF RAIN -Skinny Rings- DROUGHTS

Why do we care about trees? Tree Rings -One ring= one year *Youngest- on the outside *Oldest- on the inside

Precambrian Era 5 Major events: Formation of Sun and light Creation of Earth Creation of Atmosphere through volcanic out- gassing Creation of oceans Creation of life Simple life such as bacteria and simple algae There was a rise of simple organism such as jellyfish and sea worms by end of era. Few fossils because life forms were soft-bodied and had no hard skeleton.

Precambrian Era Precambrian lasted the longest; 88% of Earth’s history. Earth took about 3.5 billion years to form; making it around 4.6 billion years old.

Paleozoic Era Began with the early invertebrates (no backbone), such as trilobites and brachiopods; continued to develop early vertebrate fish, then arachnids and insects; later came the first amphibians, and near the era’s end the reptiles became dominant. Early land plants include simple mosses, ferns, and then cone-bearing plants. By the end of the era, seed plants were common. The mass extinction that ended the era caused most marine invertebrates as well as amphibians to disappear.

Mesozoic Era Reptiles were the dominant animals of this era, including the various dinosaurs. Small mammals and birds also appeared. Toward the end of the era, flowering plants appeared and the kinds of mammals increased. A mass extinction that ended the dinosaurs.

Cenozoic Era New mammals appeared while other became extinct. The diversity of life forms increased. Flowering plants became most common. Humans are also part of the most recent period.

Facts Scientists believe that when a sudden disappearance of many animals took place there was a mass extinction. This would show up as many fossils in one layer.