Ice Cores
The two places where we find enough old glaciers to drill down almost two miles into the ice.
What is Greenland and Antarctica?
The type of feedback that causes a system to amplify a signal.
What is a positive feedback loop?
These planets periodically combine their gravity to stretch out the ellipse of earth's orbit?
What is Jupiter and Saturn?
Isotopes have the same number of protons, but different numbers of these.
What are neutrons?
This current slowly moves up along the east coast of North America toward the North Atlantic before diving downward to become a deep-water current.
What is the AMOC?
When volcanoes erupt, this substance may drift down onto a glacier, and become part of the permanent record of tectonic activity locked away in the ice layers.
What is volcanic ash?
This positive feedback loop occurs when a warm earth melts permafrost releasing more of these gases into the air, which leads to more warming.
What are greenhouse gases?
When thinking about ice ages, we are most concerned with the Northern Hemisphere summers, because the Northern Hemisphere contains more of this than the Southern Hemisphere.
What is land surface?
This is the heavier and less common brother of oxygen 16.
What is oxygen 18?
Over the last 20 years, the pace of this Atlantic current has been doing this?
What is slowing down?
Found inside ice cores, these objects can be analyzed to determine what gases were found in the ancient atmosphere of Earth?
What are air bubbles?
This term refers to the reflectivity of a surface, usually discussed when talking about the polar ice caps.
What is albedo?
You don't necessarily need cold winters for an ice age, but you do need this in the Northern Hemisphere?
What is cool summers?
Because the oxygen 18 is 10% heavier than oxygen 16, it requires a little bit more energy to do this, an important part of the water cycle needed to form clouds.
What is evaporate?
This is believed to be the reason the AMOC is slowing down.
What is meltwater from Greenland's glaciers?
During particularly cold times, this isotope tends to be very common in ice cores?
What is oxygen 16?
This feedback loop reduces the effect of the change to help maintain a balance - if the system drifts away from normal, the feedback returns it back to normal.
What is a negative feedback loop?
The obliquity of the Earth's axis is now at 23.5 degrees, but it varies over 41,000 years from a minimum of 21.1 degrees to a maximum of this?
What is 24.5?
The hard parts of animals found in the ocean, these calcium carbonate objects will contain more oxygen 18 during cold glacial periods than they will during warmer interglacial periods.
What are seashells?
In addition to distributing heat to northern latitudes, the distribution of this substance is a another benefit to the oceans.
What is nutrients?
The deepest ice cores have been drilled down to a depth of about 2 miles, which corresponds to ice that is about this old.
What is 2 million years old?
This happens when increased atmospheric temperature leads to increased cloud formation, causing more sunlight to be reflected into space, which leads to cooling.
What is a negative feedback loop?
The Earth's 26,000 year wobble like a spinning top causes Northern Hemisphere summers to occur at either aphelion or, 13,000 years later, at this location.
What is perihelion?
We are very interested in oxygen isotopes because they are a component of this very common substance, found in the ocean and also in glaciers.
What is water?
The AMOC sequesters this substance into the deep ocean, where it can not enter the atmosphere to cause further warming.
What is Carbon Dioxide?