Gaining insight from landforms is the goal of geomorphology. Unraveling how their evolution shapes the face of a planet is an investigation that lies at the heart of this field. Geographers, geologists, geodesists, and engineers use observation, experiment, and modeling to explore these surfaces and discover hidden potential.
The breadth of studies makes for broad interests among researchers – all dedicated to understanding topography and predicting future changes. Fieldwork gives way to experiments; data points come together to form meaningful patterns.
Connecting seemingly unrelated elements and ideas is key to conceptual innovation in geomorphology. Finding fresh angles can uncover previously unseen opportunities. And learning must never end: sharpening knowledge through study helps build our capacity for creative thought.
Processes
Regolith transformation relies on weathering, erosion, and, ultimately, deposition.
Altogether, wind, waves, chemical erosion, displacement of material, groundwater flow, river action, glaciation, plate tectonics, and volcanism are all primary processes that shape the land surface.
Periglacial processes and salt-mediated action are also relevant in specific cases. Fluid seepage through the seafloor or aquatic activity from marine currents may also impact topographies. Lastly, don’t forget extraterrestrial events like asteroid impacts may have a significant role in the shaping of landforms.
Conceptual innovation is key for a full appreciation of geographically relevant processes. This means gathering data points to ask insightful questions while being flexible enough to discard assumptions when needed. Learning must be ongoing to deepen knowledge and broaden understanding of these dynamic landscapes.
Aeolian processes
Winds shape the world around us. From sculpting mountain ridges to moving sand and silt, aeolian processes are powerful forces of Nature. These processes occur mostly in dry, arid regions with sparse vegetation where winds can move unbound materials easily.
Water may be better able to mobilize material than wind in most environments, but the eroding and sediment-moving power of aeolian processes should not be underestimated. The wind has shaped fantastic landscapes and continues to work on dynamic surfaces all over the world.
These processes may even create more complex shapes than those carved by water, like dust-filled martian dunes or round pebbles found amongst Saharan sands – imprints of a windy past. Aeolian processes often leave compelling marks that illustrate Nature’s immense capability to survive the fierce tugs of the planet’s winds.
Biological processes
Biology’s interaction with landforms, or geomorphologic processes, is vast. Its influence spans from modulating chemical weathering to changing soil formation through burrowing and tree throwing. Even the global erosion rate may be altered through its effect on the carbon dioxide balance.
Yet terrestrial landscapes in which biology has no role are scarce; they could give a glimpse into how other planets, like Mars, function geographically. To understand the terrestrial geomorphic system better and gain insight into extraterrestrial geomorphology, it is essential to study the interaction between living organisms and landforms.
Fluvial processes
Rivers are the conduit of both water and sediment. As they flow, rivers draw up particles from its bed and transport them downstream, either suspended in the water or actually rolling along their surface. This movement, called sediment transport, depends upon how much sediment is available in the river and its discharge rate. Rivers also erode rocks to create more sediment for themselves as well as contribute to areas bordering them. They’re a major link in connecting different landscape segments and widely form dendritic drainage systems when underlying strata are stable.
River networks grow larger by incorporating another river-up system. At their endpoint, water merges with a receiving basin completing the four-part structure of the drainage system: namely, drainage basin, alluvial valley, delta plain, & receiving basin. Examples of geomorphic features created by fluvial action are alluvial fans, oxbow lakes, and fluvial terraces.
Glacial processes
Glaciers shape landscapes. They move ice down valleys, causing abrasion of the underlying rock. This leads to glacial flour – fine sediment. When glaciers recede, leftover debris is called a moraine. Valleys eroded by glaciers take on a U-shaped form due to the erosive properties of ice.
Plio-Pleistocene environments have been strongly impacted by glacial processes, termed paraglacial. The paraglacial change includes landscape alteration from glaciation and cold climate modifications that persist long after its disappearance. Periglacial processes are directly linked to either the formation or melting of ice and frost; they complement but are different from paraglacial ones.
Hillslope processes
Gravity powers mass wasting, the movement of soil, regolith, and rock downslopes on Earth and other planetary bodies. Slope processes alter sloping surfaces and can produce drastic results; when slopes exceed certain thresholds, large amounts of material can be quickly detached. Some processes on Earth are additionally influenced by organisms such as burrowers and tree throwers.
Hillslope degradation affects a wide range of areas, highlighting the need to understand the dynamics of slope evolution. Knowing how biological forces interact with hillslope processes can help us develop solutions for dealing with losses caused by landslides. Further research may reveal insights into this complex system that we have yet to uncover.
Igneous processes
Volcanoes and plutonic rocks play key roles in geomorphology. Eruptions bring lava and tephra that can reshape landforms, while intrusions of material solidify beneath the surface and lead to either uplift or subsidence.
Rivers often take new paths with such changes, while volcanoes build up topography that provides fresh surfaces for surface processes to act on. To account for these impacts, one must consider both eruptive and intrusive forces. It is through this framework, mixing creative problem-solving with illuminating insights, that we tap into our conceptual intelligence.
Tectonic processes
Tectonics’ effects on geomorphology vary from scales of minutes to millions of years. Bedrock fabric largely determines the local morphological shape resulting from tectonics. Earthquakes in minutes can submerge areas, creating wetlands. Isostatic rebound happens over hundreds to thousands of years, and eroding mountains sustain erosion through mass removal and uplift.
Orogenic belts are long-term mountain chains with lifespans running tens of millions of years, acting as sedimentation points for fluvial and hillslope processes. Mantle dynamics such as plumes and delamination create an opposite isostasy effect by heating up mantle rocks, causing surface re-uplift.
Marine processes
Defined by motion, marine processes encompass the action of waves, currents, and seepage. Mass wasting and submarine land sliding are also core components.
Ocean basins act as receptors for a vast proportion of terrestrial sediments, making depositional processes influential to marine geomorphology. Resulting features such as sand fans and deltas feature prominently too.
