Earth science begins to look at geology, time and life together.
Upon completion of seventh grade, Earth science students are generally expected to have a basic grasp of mineral composition, geological dynamics like plate tectonics and volcanoes, and the impact of human activity on systems affecting land, air and water. These general areas are rich in subtopics that are not merely informative but also interesting to an inquisitive 12-year old.
Oceans
What is the density and pressure of water one mile below the surface of the ocean? Earth science in the seventh grade begins to introduce students to big scales and big forces. This topic involves mass and density, physical properties, as well as oceanic geography. Related topics might include life forms a mile below the ocean surface. Another ocean topic is formation of present oceans by continental drift and the separation of Pangea, the supercontinent. This topic involves the description of geologic time.
Time and Awe
Geologic time is not available to younger students who haven't mastered the basic mathematical skills enough to appreciate scale. But writing about segments of geologic time, especially if the student is asked to make comparisons to illustrate geologic time, can boggle their minds and instill them with a sense of wonder at the true scope of reality. Plotting a single lifetime against the history of humanity, then plotting that period against the history of the Earth, is sure to give the student writer some moments of pause and reflection.
Geologic Drama
Giant rafts of land floating on a worldwide ocean of molten rock is a reality, but no students notice this in their daily lives. Writing about plate tectonics means writing about big forces, about volcanoes and earthquakes, fault lines and catastrophes, mountains being crushed into existence and oceans appearing and disappearing. Weather-plotting whole ages in a paper will cause students to think of glaciers gouging out the Great Lakes, of Europe freezing in summer, of dinosaurs and giant, long-gone mammals. These writing topics may be the spark that ignites a future seismologist, meteorologist, geologist or paleontologist.
Being Part of the World
Seventh grade is an period when some students begin to develop a sense of ethics or an attitude that raises the question of how people ought to relate to the circumstances of their lives. Topics relating to human impact on Earth systems are both interesting and disconcerting, given the alarms that have been raised in past decades about sustainability of systems, biodiversity and climate change. Topics that force them to engage these questions with the actual science that studies these questions will do more than amplify their understanding of earth science; it may make them more conscientious, thoughtful people.
Tags: against history, geologic time, mile below, plate tectonics, seventh grade