Ocean currents
Which factors determine the density of ocean water.
Temperature
Salinity
True or False: Climate describes the day-to-day conditions of the atmosphere, while weather describes the average conditions over a long period of time.
False — Weather refers to short-term atmospheric conditions (such as today's temperature, rainfall, and wind), while climate refers to the average weather patterns of a region over a long period of time (typically 30 years or more).
Name two greenhouse gases that contribute to the greenhouse effect.
Methane
Carbon Dioxide
Ozone
Water Vapour
True or False: Scientists can use the width of tree rings to learn about past climate conditions, such as periods of drought or abundant rainfall.
True — Wider tree rings generally indicate years with favourable growing conditions (such as adequate rainfall and suitable temperatures), while narrower rings can indicate environmental stress, such as drought or colder conditions.
What is the largest planet in our Solar System?
Jupiter
What happens to cold, salty water around the poles, and why?
Cold, salty water becomes very dense and sinks to the bottom of the ocean. This sinking water helps drive deep ocean currents as part of the global thermohaline circulation (the "global ocean conveyor belt").
List two factors that affect climate and describe how each factor influences temperature or rainfall.
Other acceptable factors include: altitude, distance from the sea, prevailing winds, and topography (mountains).
How is the enhanced greenhouse effect different from the natural greenhouse effect?
The enhanced greenhouse effect occurs when human activities increase greenhouse gas concentrations, causing more heat to be trapped and leading to global warming.
List three types of evidence that climate scientists can use to reconstruct past climate data.
living things: tree rings, coral reefs, clam shells
ice cores
lake and ocean sediments
landscapes
rocks
fossils
Which country is home to the Great Pyramid of Giza?
Egypt
Explain the relationship between the temperature, salinity and density of water, and how variations in these properties generate ocean currents
Temperature and salinity affect the density of seawater. Cold water is denser than warm water, and salty water is denser than less salty water. When seawater becomes cold and salty, it sinks, while warmer, less dense water rises. These differences in density create movement in the oceans called thermohaline circulation, which drives deep ocean currents and helps distribute heat around the planet.
How does global warming contribute to rising sea levels?
Global warming causes glaciers and ice sheets to melt, adding more water to the oceans. It also causes seawater to expand as it warms (thermal expansion), which further increases sea levels.
Burning fossil fuels releases carbon dioxide into the atmosphere. Explain how this can lead to an increase in global temperatures.
Burning fossil fuels increases atmospheric CO₂ levels. Higher concentrations of greenhouse gases trap more outgoing infrared radiation, enhancing the greenhouse effect and causing Earth's average temperature to rise.
Describe how the scientists are able to tell what the concentrations of greenhouse gases were in the past from the ice.
The ice contains bubbles of ancient atmosphere that were trapped when the ice formed. By drilling ice cores, scientists get samples of ice from different depths corresponding to different points in the past. They can take slices from any layer and analyze the concentration of greenhouse gases in the bubbles, giving them a direct insight into the composition of the atmosphere in the past.
What is the only mammal capable of true flight?
A bat
Which element has the chemical symbol Au?
Gold
What is the name of the imaginary line at 23.5° South latitude that marks the southernmost point where the Sun can be directly overhead?
Tropic of Capricorn