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Teaching Introductory Geoscience Courses in the 21st Century
Cutting Edge > Introductory Courses > Misconception List

'Easier to Address'* Earth Science Misconceptions

*as opposed to questions of scale, time, 4-dimensional processes, etc.

(also does not include deep time or evolution as there are lots of web resources for those)

by Kent Kirkby, University Of Minnesota, with additions provided by participants in the session about misconceptions at the 2008 workshop.

Science Itself:

Science is the objective accumulation and testing of facts - ignoring its social nature and emphasis on explanatory ideas (this is the way textbooks describe science and the way it is most often taught in secondary education classes).

Science is always done following the exact steps of the scientific method (this is also the way textbooks describe science and the way it is most often taught in secondary education classes).

Earth's Setting:

Planet orbits are strongly elliptical (this is due to orbits being shown from oblique view in most textbooks to save page space).

Pluto lies at limit of solar system (again tied to text illustrations designed to save space).

Moon is typical size for moons in general

Life exists on Earth because the Earth is the right distance from the Sun for water to exist in liquid form.

Earth's Structure:

Crust and Lithosphere (or plates) are synonymous terms

Asthenosphere is liquid (students are only familiar with liquid convection, not solid convection, many secondary education earth science films also specifically refer to a molten internal layer, and some fundamentalist religious groups specifically refer to the existence of a molten layer that is hell's physical location).

Lower Mantle is liquid (for reasons similar to above).

Earth's core is hollow, or that large hollow spaces occur deep within Earth (a relict of older cosmology and a mainstay of popular literature and Hollywood movies)

Plate Tectonics:

Only continents move (Wegener's original concept, along with the common use of 'Continental Drift' term in general texts, secondary education earth science films, etc.)

Most crust motions (especially those associated with processes of mountain building or deep sea trench formation) are due to vertical motions, not lateral (terms like 'mountain uplift' and earth science textbook terminology, as well as relict idea from old cosmologies).

Divergent ocean ridges are due to vertical uplift or convergence, rather than divergence (In students' experience, buckling is usually due to convergence or uplift, not heat/density differences, so illustrations of ridges do not readily fit with a pulling apart motion).

Present oceans only began as Pangea broke apart - tied to general idea that Pangea was the original continent at the Earth's start (few educational earth science films mention what came before Pangea & emphasis on Atlantic spreading leads to Pacific being overlooked).

Plate movement is imperceptible on a human timeframe (common use of fingernail growth analogy is only true for slowest plates and underestimates importance of motion).

Plate motion is rapid enough that continent collision can cause financial and political chaos, while rifting can divide families or separate a species from its food source.

Oceans are responsible for oceanic crust (rather than being closer to other way round).

Continental 'shelves' are similar to shelves in homes, extend out over edge of continent and can break and collapse to form tsunamis (so Boxing Day tsunami was due to shelf collapse)

The edge of a continent is the same thing as a plate boundary.

Over time there has been no significant change in ratio of oceanic to continental areas (idea of stasis is a common misconception, but this was also part of Lyell's original concept).

Apart from differences due to changes in ice volume, sea level has remained relatively constant through time (recognition of impact of plate speed on sea level not even recognized by geologists until relatively recently).

A plate boundary type is the same thing as a plate. For example, a plate has to be divergent or convergent.

Earthquakes:

Earthquakes are rare events (media coverage of earthquakes is limited and biased to U.S. area or high death tolls)

The ground cracks opens during an earthquake to swallow people and buildings (common to Hollywood movies and popular literature like 'Clan of the Cave Bear' and Shogun', but also dates to early reports of Lisbon earthquake and confusion over landslides, etc.).

Earth shaking is deadly (as opposed to building collapse, tsunamis, landslides, fire, etc.)

Seismic waves involve the long distance net motion of particles

Seismic waves go from crust to core, but not core to crust (textbooks seldom specifically discuss second half of journey apart from a general treatment of shadow zones).

S-waves (shear waves) do not reach other side of Earth from where earthquake originated because they cannot pass through oceans (or cannot reach islands).

Wind blowing through subterranean passages causes earthquakes (Aristotle's hypothesis, tied with older cosmology of hollow passages through earth)

Earthquakes occur from collapse of subterranean hollow spaces (tie to older cosmologies).

The biggest earthquake is a magnitude 10.

Mineral and Rock Terms:

Separations along bedding plane, like those that dominate most sedimentary outcrops, occur deep beneath the Earth's surface.

Rocks (and minerals) grow.

Coarse-grained rocks are rough, fine-grained rocks are smooth

Coarse-grained sedimentary rocks cooled slowly, coarse-grained igneous rocks formed in areas of high depositional energy, etc.

With minerals, the term 'massive' texture means that the samples are big.

There is little to no relationship between outcrops and bedrock, and at least in Upper Midwest the whole concept of what is bedrock is fairly nebulous (I suspect students in mountainous areas may have a better concept of 'bedrock', but do not know...).

Volcanoes:

Magma comes from molten layer beneath Earth's crust (older cosmologies, Franklin's idea, as well as popular literature such as Dante's Inferno, and some religious tracts).

Magma comes from deep within Earth's mantle (common textbook and earth science educational movies use of 'deep' terminology, older cosmology of passage-filled Earth')

Magma comes from Earth's outer core (this one tends to increase as students realize there is no molten layer in the mantle).

Basalt's origin is connected to the presence of seawater (original concept and name, coupled with its association with oceanic crust and oceanic hotspots vs. continental)

Volcanic eruptions are rare events (media coverage is biased by location and death tolls).

Volcanoes are dominantly tropical features (Gilligan Island phenomena, common depiction)

Most deaths during volcanic eruptions are due to suffocation from smoke or poisonous gases (older scientific hypothesis until 1902 Pelee eruption, real life knowledge that many deaths in fires due to smoke inhalation, as well as being specifically mentioned as such in secondary education earth science films, all primarily legacy of Pompeii casts).

Most deaths during volcanic eruptions are due to fear and panic during evacuation (real life knowledge of crowds, Hollywood depictions).

Most magma forms as rock melts due to an increase in temperature (in real life this is the way most things melt, coupled with knowledge that temperature rises within Earth).

Most magma forms as rock is subjected to great pressure deep within the Earth (since increased pressure makes rock easier to deform or convect, even greater pressure should turn it to liquid - or so it seems).

Wind blowing across the tops of volcanic mountains can cause eruption, similar to wind blowing over opening of a flute (older cosmology dating back to Greeks)

Most volcanoes are tall peaks with craters at summit (bias of photographic record, pretty volcanoes most photographed, subduction volcanoes more accessible than submarine)

Whole idea of common use of active, dormant and extinct terms having geologic validity.

Volcanoes are only hazards, not important long-term resources.

Paleomagnetism:

The Earth's core acts like a permanent bar magnet

Magnetic reversals can result in mass extinctions, natural disasters, etc. (original scientific hypothesis for origin of mass extinctions, also Hollywood movies).

Ocean Systems:

Sea level is level (reinforced by common use of sea level as base for surveying).

Sea level is constant - apart from changes due to ice volume (ignoring changes due to temperature or long term changes in speed of plate motions).

Coastlines are continent edges, the edges of continental crust, or plate boundaries.

Coastal systems and ocean systems tend to be constant through time (stasis).

Waves and surf are synonymous terms - or wave motion involves net long distance movement of water particles (common use of 'waves' for surf, knowledge of message bottles cast into water traveling long distances).

Tsunamis are immense (100's of feet tall) waves/surf (Hollywood depictions)

Second tidal bulge (away from Moon) is due to Moon's reduced gravitational attraction <a>(specifically described as such in many textbooks).</a>

Second tidal bulge (away from Moon) is due to Moon pulling solid Earth more than water (again specifically described in many of the textbooks that do not claim the above).

Ocean currents, like North Atlantic Current) sink because of their temperature (works with air masses, and air circulation system is familiar, simple and symmetrical).

Upwelling occurs as deeper water layers warm and rise (again tied to students' knowledge of how air masses are affected by temperature).

Next two are secondary misconceptions that typically arise during class rather than prior:

Upwelling occurs as deeper water layers lose their salinity and rise (students like symmetry!).

Salinity changes produce temperature changes or vice versa

River Systems:

Streams are simply flowing water (with little to no concept of sediment movement).

Rivers flow south - sometimes modified to rivers in northern hemisphere flow south, while those in southern hemisphere flow north.

Concept of 30-year,100-year, 500-year floods meaning set time intervals between events, rather than water heights.

Idea that human activities cannot affect geological processes like river flow, flood cycles, etc.

The idea that increased water improves or aids wetland areas/environments

Most of following are tied to general idea of 'stasis', the idea that the Earth's surface and geological processes do not fundamentally change over time.

Floods are rare, atypical, almost unnatural events rather than normal river behavior.

Rivers do not carve valleys, but only passively flow down them (this is an old idea, the role of rivers in sculpting the land surface was not even recognized by most geologists until the exploration of the southwest United States by Powell's and other early surveys).

Although rivers can cut down over time, they do not cut to the sides (inadvertently aided by widespread attention paid to Grand Canyon, and Goosenecks in earth science texts).

Waterfalls can increase in height over time, but do not retreat (again stasis, the idea that features do not fundamentally change is a common problem).

Deserts:

Deserts are relatively rare (relatively few humans live in them, so not familiar to most students)

Deserts are hot (Hollywood depictions, cartoons, and best known deserts are warm areas.

Deserts are sand-covered areas (Hollywood depictions and bias of photographic record).

Deserts are subject to extreme temperature changes as freezing nights alternate with blazingly hot days.

Deserts only occur in subtropical settings or inland areas far removed from oceans.

There is little to no life in desert areas.

Groundwater & Karst Systems:

Groundwater primarily exists as vast subterranean rivers, lakes and seas (difficulty of conceiving of water flow through 'solid' rock, as well as older cosmologies, Hollywood movies and familiarity with surface water flow).

In contrast, the idea that groundwater only exists within pores of rock (some underground rivers and lakes really do exist and in many areas are more important than matrix flow!)

Groundwater and spring waters are pure, naturally filtered water systems (filtering emphasized in some texts & common literature, as well as Madison Avenue advertising).

There is no real connection between groundwater and surface water systems.

Groundwater is largely paleo-water from earlier periods in Earth's history (emphasized in many textbooks and focus on aquifers problems where this is true to some extent).

Lakes and rivers contain more freshwater than groundwater systems do.

Caves extend deep within the Earth (legacy of older cosmology and popular literature).

Glacial Systems:

The 'Ice Ages' happened in the past and are now over (common text book and science education movie terminology, as well as Hollywood movies and original hypothesis).

The present Ice Caps have always existed on Earth, although their size has changed through time (few texts specifically mention that ice ages are the exception, not the rule).

Glaciers can metamorphose rock (since they can erode and depress crust, why not alter it? textbook and movie emphasis on glacial efficiency and reinforced by common association of metamorphosed Precambrian rock exposed in glacial areas.

Glaciers are only moving ice masses (with little to no concept of sediment transport).

Glacial ice moves backwards during glacial 'retreats' (like everything that retreats in real life)

Glacial ice is stationary during times when front is neither advancing or retreating.

Glacial retreat and advance is just motion of whole ice cap back and forth (sort of like a bad toupee) with no significant change in total ice volume (again idea of stasis).

Use of 'bulldozer' analogy for glacial movement and sediment transport (earth science textbooks and secondary earth science education films).

Idea of four ice ages still prevalent in general earth science literature.

Climate:

Equator is warmer because the tropics are closer to the Sun. (older cosmology dating to Icarus myth, depictions in earth science textbooks, real life experiences with heat sources)

Summer is warmer because we are closer to Sun during those months.

Tropics are warmer because they are closer to the Earth's core.

Tropics are warmer because they have more volcanoes.

Tropics are warmer because there is more water located there to absorb heat.

Earth's climate is controlled primarily by the atmosphere circulation, rather than ocean circulation (real life experiences as a terrestrial animal, TV weather reports)

Greenhouse Warming:

Earth is primarily warmed directly by sunlight (real life experience, walk into sunlight you get warm, it is difficult to disassociate sunlight from heat coming off surrounding surfaces)

Greenhouse warming works like greenhouses do (specifically mentioned in many texts).

Greenhouse warming is an unproven concept (tied to politics and confusion over greenhouse warming and climate change due to human activities).

Greenhouse warming is only due to human activities (flip side of above confusion).


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