tectonics Tectonics (; ) are the processes that control the structure and properties of the Earth's crust and its evolution through time. These include the processes of mountain building, the growth and behavior of the strong, old cores of continents k ...

, vertical displacement refers to the shifting of land in a

vertical direction In astronomy, geography, and related sciences and contexts, a '' direction'' or '' plane'' passing by a given point is said to be vertical if it contains the local gravity direction at that point. Conversely, a direction or plane is said to be ho ...

, resulting in uplift and

subsidence Subsidence is a general term for downward vertical movement of the Earth's surface, which can be caused by both natural processes and human activities. Subsidence involves little or no horizontal movement, which distinguishes it from slope move ...

. The displacement of rock layers can provide information on how and why Earth's lithosphere changes throughout geologic time. There are different mechanisms which lead to vertical displacement such as tectonic activity, and isostatic adjustments. Tectonic activity leads to vertical displacement when crust is rearranged during a

seismic Seismology (; from Ancient Greek σεισμός (''seismós'') meaning "earthquake" and -λογία (''-logía'') meaning "study of") is the scientific study of earthquakes and the propagation of elastic waves through the Earth or through other ...

event. Isostatic adjustments result in vertical displacement through sinking due to an increased load or

isostatic rebound Post-glacial rebound (also called isostatic rebound or crustal rebound) is the rise of land masses after the removal of the huge weight of ice sheets during the last glacial period, which had caused isostatic depression. Post-glacial rebound ...

due to load removal.

Tectonic causes of vertical displacement

Vertical displacement resulting from tectonic activity occurs at divergent and convergent plate boundaries. The movement of magma in the

asthenosphere The asthenosphere () is the mechanically weak and ductile region of the upper mantle of Earth. It lies below the lithosphere, at a depth between ~ below the surface, and extends as deep as . However, the lower boundary of the asthenosphere is not ...

can create divergent plate boundaries as the magma begins to rise and protrude weaker lithospheric crust. Subsidence at a divergent plate boundary is a form of vertical displacement which occurs when a plate begins to split apart. As intrusive magma widens the

rift zone A rift zone is a feature of some volcanoes, especially shield volcanoes, in which a set of linear cracks (or rifts) develops in a volcanic edifice, typically forming into two or three well-defined regions along the flanks of the vent. Believed t ...

of a divergent plate boundary the layers of crust on the surface above the rift will subside into the rift, creating a vertical displacement of those layers of surface crust. Convergent plate boundaries create orogenies such as the

Laramide orogeny The Laramide orogeny was a time period of mountain building in western North America, which started in the Late Cretaceous, 70 to 80 million years ago, and ended 35 to 55 million years ago. The exact duration and ages of beginning and end of the o ...

that raised the Rocky Mountains. For this orogen event dense oceanic crust from the Pacific plate subducts beneath the less dense continental crust of the North American plate as they converge. This subduction induced the compression of the bounded western region of the North American plate which created the uplift of different layers of rock. This vertical displacement created the various mountain formations which are cumulatively known as the Rocky Mountain range.

Earthquakes An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, from ...

are one mechanism that leads to vertical displacement of crust. The fracturing of land during an earthquake creates a fault when land is displaced during the event. The throw of the fault is a term used to describe and quantify the magnitude of this displacement.

Glacial isostatic adjustment

Changes in

glaciation A glacial period (alternatively glacial or glaciation) is an interval of time (thousands of years) within an ice age that is marked by colder temperatures and glacier advances. Interglacials, on the other hand, are periods of warmer climate betw ...

can lead to the vertical displacement of crust. Glaciers and ice sheets residing on top of landmass result in an

isostatic depression Isostatic depression is the sinking of large parts of the Earth's crust into the asthenosphere caused by a heavy weight placed on the Earth's surface, often glacial ice during continental glaciation. Isostatic depression and isostatic rebound ...

, or sinking, in a section of lithospheric crust due to the weight of the ice. Likewise,

, or uplift, occurs when glaciers and ice sheets recede. Using asthenosphere

viscosity The viscosity of a fluid is a measure of its resistance to deformation at a given rate. For liquids, it corresponds to the informal concept of "thickness": for example, syrup has a higher viscosity than water. Viscosity quantifies the inter ...

data researchers are able to determine the rate by which isostatic rebound occurs. Isostatic rebound occurrence rate can be determined by comparing local viscosities to the maximum viscosity of the asthenosphere. Areas with higher viscosity are subject to quick isostatic rebound while in regions of low viscosity crustal uplift occurs at a slower rate. Uplift is still occurring through isostatic rebound from the

Last Glacial Maximum The Last Glacial Maximum (LGM), also referred to as the Late Glacial Maximum, was the most recent time during the Last Glacial Period that ice sheets were at their greatest extent. Ice sheets covered much of Northern North America, Northern Eur ...

. Glacial isostatic rebound leads to sea level regression which can be measured using ¹⁴C dating to determine the age of

sublittoral The littoral zone or nearshore is the part of a sea, lake, or river that is close to the shore. In coastal ecology, the littoral zone includes the intertidal zone extending from the high water mark (which is rarely inundated), to coastal areas ...

sediment in different regions along the seafloor.

Notes

{{reflist Plate tectonics Vertical position