Which forces control the elevation of mountains?

Which forces control the elevation of mountains? It depends, say scientists and propose a novel classification scheme in a new study.

Scientists have come up with a new classification scheme for mountain belts that uses just a single number to describe whether the elevation of the mountain belt is controlled mainly by weathering and erosion or by properties of the Earth’s crust, i.e., the lithospheric strength: the “Beaumont number” (Bm). It’s named after Chris Beaumont, a scientist who, together with his team, developed coupled models of surface processes and tectonic forces. The scientists report about their findings in the current issue of Nature.A Beaumont number between 0.4 and 0.5 means that the mountains are in a so-called flux steady state in which the controlling factors of mountain growth are tectonic forces and the lithospheric strength, balanced by weathering processes as, for example, in Taiwan. With a Bm value lower than 0.4, mountains are also in a flux steady state but with erosion as controlling factor like the Southern Alps of New Zealand.  A Beaumont number above 0.5 means that the mountains still grow (non-steady state) with lithospheric strength controlling the process. Examples for this type are the Himalaya-Tibet mountains and the Central Andes.

This classification is resolving a long-standing question whether tectonic forces and strength of the Earth’s crust are the controlling factors of mountain elevation or weathering processes. The new study says it can be one or the other – depending on geographic location, climate and underground properties.

The team of scientists led by Sebastian G. Wolf of Bergen University in Norway used a new coupled surface process and mantle-scale tectonic model for their study by combining the thermomechanical tectonic model FANTOM with the landscape evolution model FastScape. Thus, they were able to reconcile high erosion rates in some active orogens with long-term survival of mountain belts for hundreds of millions of years.

Jean Braun of the GFZ German Research Centre for Geosciences, who co-authored the paper, says: “With our Beaumont number we can determine to which proportion tectonics, climate, and crustal strength control the height of mountain belts. And, for most mountain belts, this can be done without complex measurements or assumptions; all that is needed is a knowledge of the rate of convergence obtained from present-day plate velocities or plate reconstructions, the height of the mountain obtained from a topographic map and the widening rate obtained from the geological record. In a nutshell: Whether a mountain is short or tall is the product of slow or fast convergence, wet or dry climate, or strong or weak crust.” The Beaumont number shows which of these three factors is dominating.

Original study: Sebastian G. Wolf, Ritske S. Huismans, Jean Braun & Xiaoping Yuan: “Topography of mountain belts controlled by rheology and surface processes”; in Nature. DOI: 10.1038/s41586-022-04700-6. Link: https://www.nature.com/articles/s41586-022-04700-6


Scientific contact:
Prof. Jean Braun
Tel: +49 331 288-27520
Tel: +49 162 4255672

Additional News

Schematic of plunging Earth plates under the ocean with water transport and the Al molecules involved: This is how water migrates deeper into the Earth than previously assumed.

Water is seeping deeper into Earth than expected

From the air, a view of Istanbul, a city of millions, and the surrounding sea.

"Earthquakes don’t occur out of nowhere"

Group photo with all the people who attended the farewell

Honouring Prof. Onno Oncken with a scientific colloquium

DEUQUA Logo mit Mammut und Friedenstaube

DEUQUA 2022 Tagung am GFZ

PAW Logo

Postdoc Appreciation Week Germany

Building, photo taken in winter, Isaac Newton Institute

Simons Scholarship for Dr Monika Korte

Die Verteilung der seismischen Stationen auf einer Karte der Region.

How deeply does Eifel volcanism sleep?

Geomagnetic Field. Space with stars, Earth with animation around

GFZ film among the finalists of the Earth Futures Festival 2022

Earth's radiation belt: High-energy particles modelled around the Earth. The particles are ring-shaped

A new population of particles in the Earth’s radiation belts

[Translate to English:] Die teilnehmenden GFZ Mitarbeiter als Gruppenfoto

2nd proWissen run in Potsdam with successful participation by GFZ employees

The group on the first day of work.

New faces at the GFZ - start of the training year 2022/2023

Forest vs no forest on two sides of a road

Agriculture drives more than 90% of tropical deforestation

Group photo: people on the roof terrace of a house

2nd International Symposium of International Association of Geodesy’s Commission 4…

[Translate to English:] Foto eines Bergs mit darüber gelegter Skizze des geologischen Profils.

How thick should clay be as a host rock for a repository?

White dots of different thicknesses in a hexagonal pattern on a black ground.

Synthesis of hexagonal SiGe semiconductor using high pressure and temperature

Landslide on a slope directly adjacent to a settlement with small houses.

Landslides increasingly threaten the world's urban poor cities

Different coloured liquids mix in an aquarium. A child watches.

Catching up after Corona: "GEOtogether" brings joy for pupils in collaborative…

A woman and a man stand on a stage holding a picture with a coloured map of Türkiye..

Four decades of joint Turkish-German earthquake research

Egon Althaus sitting around a table with colleagues outside on a project

We mourn the death of Egon Althaus (1933-2022)

A dry dam near Capetown, South Africa.

The challenge of unprecedented floods and droughts in risk management

Drawing of a fictional historical submersible.

Eleven short research stays with GFZ participation funded

Drilling platform on Lake Junin with several people on it

Tropical glaciers followed the rhythm of the ice sheet expansion in the northern…

Schematic representation of the VECTOR project: A large arrow with different levels - from the earth's surface to underground.

Improving the exploration efficiency in Europe

Hoby Razafindrakoto

Project from Dr. Razafindrakoto to create a seismological lab in Madagascar wins ARISE…

3D digital Earth at night

Open-Earth-Monitor getting started

The dam of the Steinbach Dam in the Eifel region, cut by flooding but not destroyed.

Flood risk management after the Eifel flood in July 2021

Group picture of the Cermak7 Conference in front of the Museum Barberini in Potsdam

International heat flow conference and workshop in Potsdam

Castor platform in the ocean. The sea is still.

Filling geological gas reservoirs: Causal research in the most important event of induced…

People sit on chairs in a circle in a room.

GFZ PhD Days

Jeffrey Perez in front of the Logo of the meeting

Two GFZ Researchers participate in the 71st Lindau Nobel Laureate Meeting

back to top of main content