Tuesday, 2/16

Tuesday, 2/16

Agenda

• Bell Ringer

• Lesson - Earth's Changing Environment

• Webquest

• Exit Ticket

Open Ended

In your own words, what is a mass extinction event?

Changing Earth

• Environmental conditions on Earth change constantly.

• Depending on the nature of the changes and the organisms involved, life has responded in different ways—some have changed, some new have evolved, and/or some have become extinct.

• Let's look at some of these changes...

Flooding

• A flood is an overflow of water from streams, lakes, and rivers onto land that is normally dry.

• This changes the Earth's surface through erosion and the movement of soil, rocks, and sand

Fires

• Fires are a natural part of the life cycle of ecosystems. They can be started by lightning strikes, volcanic eruptions, or sparks from falling rocks.

• Effects: allow new plants to grow, destroy vegetation, destroy animal habitats, release ash into air

Volcanic Activity

• Volcanic activity can rapidly disrupt many of Earth's processes and ultimately the lifeforms that depend on those processes.

• In some cases, these catastrophes can cause extinctions and mark the end of one geologic era and the beginning of another.

Asteroids/Comets

• Occasionally, large objects such as asteroids and comets collide with the Earth and other planets.

  While these impacts are extremely rare, they can cause widespread catastrophes affecting the environment at a large scale.

Asteroids/Comets

• Large impacts throw large volumes of dust into the atmosphere, which can block out the Sun and cause major climate change.

• Many scientists agree that an impact of an asteroid or comet caused the extinction of the dinosaurs and many other groups of organisms at the end of the Mesozoic era.

Climate Change

• The climate on Earth has been constantly changing through time. Gradual climate changes can cause changes in Earth's lifeforms.

• For example, Earth has been influenced by many ice-age climate changes during Earth's current era, the Cenozoic. During the Cenozoic era, ice sheets and glaciers have advanced and retreated many times.

Human Impact

• There are over seven billion humans on the Earth, and that number is constantly growing.

• As the number of humans increases, so does the consumption of natural resources and the rate at which forests and grasslands are transformed into farmland, home sites, roads, and parking lots.

Human Impact

• Human activity is the main cause of modern day extinction.

• Humans impact the environment through: habitat destruction, habitat division, pollution, and hunting

Webquest

• Click on the link in the chat box to go to the Webquest

• 10 minutes to complete

Exit Ticket

• Complete your exit ticket in Canvas

• Once I've received your exit ticket, you are good to go.

• Have a great rest of your day!