Mass Movement

Definition

Mass movements can be defined as as any type of downslope movement of earth materials, such as sediment, soil and rock material. Mass movements are processes of erosion, transport and accumulation of material that occur on both gentle and steep slopes mainly owing to gravitational forces (IRDR Glossary).

These movements are generally associated with other disasters such as earthquakes, floods, thunderstorms and heavy rainstorm. They can be also associated with manmade hazards like construction roads, buildings, structures, infrastructure facilities.

 

Facts and figures

Mass movements occur based on several factors and causes differ depending on different regions. Mass movements are affected by the slope gradient, climate, rock type and structure, physical setting and geological and geomorphological outlines (Advances in Geosciences).

Mass-wasting events come in many shapes, sizes and speeds. Typically, the steeper the angle of a slope, the faster will be the down-slope movement of rock and sediment.  Also, water can play a significant role in mass wasting, sometimes acting as the key component to a mass-wasting event, or serving as a lubricant within a mass of sediment and rock, enabling it to travel faster and further than it would otherwise.

 

One type of mass wasting can evolve into another type of mass wasting as the body of sediment/rock moves down a slope. This can make it difficult to classify a single event as being one type of mass wasting or another (Department of Geological Sciences, California State University).

A simple classification of the different types of mass wasting can be:

  • Falls  (rock fall and rock avalanche)        
  • Slides  (rock slide, landslide and slump)      
  • Flows  (rock avalanche, debris flow, earth flow and creep).

UN-SPIDER Regional Support Offices with hazard-specific expertise

Related content on the Knowledge Portal

  • Landsat 3 was launched on March 5, 1978, three years after Landsat 2.
    The Landsat program’s technical and scientific success together with political and economic pressures lead to the decision to commercialize an operational Landsat. To this end, responsibility was slated to shift from NASA (a research and development agency) to the National Oceanic and Atmospheric Administration (NOAA), the agency charged with operating the weather satellites. This was done via Presidential Directive/NSC-54 signed on Nov. 16, 1979 which assigned NOAA “management responsibility for civil operational land remote sensing activites.” (However, operational management was not transfered from NASA to NOAA until 1983).
    Landsat 3 carried the same sensors as its predecessor: the Return Beam Vidicon (RBV) and the Multispectral Scanner (MSS). The RBV instrument on-board Landsat 3 had…

    read more
    05/03/1978
  • Landsat 2 was launched into space onboard a Delta 2910 rocket from Vandenberg Air Force Base, California on January 22, 1975, two and a half years after Landsat 1. Originally named ERTS-B (Earth Resource Technology Satellite B), the spacecraft was renamed Landsat 2 prior to launch. The second Landsat was still considered an experimental project and was operated by NASA.
    Landsat 2 carried the same sensors as its predecessor: the Return Beam Vidicon (RBV) and the Multispectral Scanner System (MSS).
    On February 25, 1982 after seven years of service, Landsat 2 was removed from operations due to yaw control problems; it was offically decommissioned on July 27, 1983.

    Instruments:
    Return Beam Vidicon (RBV)
    Multispectral Scanner (MSS)
     

    read more
    22/01/1975
  • Landsat 1 was launched on July 23, 1972; at that time the satellite was known as the Earth Resources Technology Satellite (ERTS). It was the first Earth-observing satellite to be launched with the express intent to study and monitor our planet’s landmasses. To perform the monitoring, Landsat 1 carried two instruments: a camera system built by the Radio Corporation of America (RCA) called the Return Beam Vidicon (RBV), and the Multispectral Scanner (MSS) built by the Hughes Aircraft Company. The RBV was supposed to be the prime instrument, but the MSS data were found to be superior. In addition, the RBV instrument was the source of an electrical transient that caused the satellite to briefly lose altitude control, according to the Landsat 1 Program Manager, Stan Weiland.
    To help understand the data and to explore the potential applications of this new technology, NASA oversaw 300 private research investigators. Nearly one third of these were international scientists…

    read more
    23/07/1972
  • The National Research and Innovation Agency of Indonesia (BRIN, UN-SPIDER Regional Support Office in Indonesia) recently discussed the use of remote sensing technology in landslide mitigation.

    Landslides occur frequently throughout Indonesia, and at a much higher rate when compared to other natural disasters such as floods, windstorms and earthquakes, with 7024 incidents occurring in the last decade. The Head of the BRIN Geoinformatics Research Center spoke on how improvements in remote sensing technology have enabled the production of high resolution imagery that can be used to detect land cover changes and map hazards like landslide occurrences. Additionally, the accessibility of publicly available datasets and imagery has grown, making such practices more cost effective as well.

    With the continual developments in the field of remote sensing, BRIN and other research organizations will be able to to study the occurrences of…

    read more
    Regional Support Offices mentioned:
    09/05/2024
  •  

     

     

  • L'Institut Géographique Agustin Codazzi (IGAC) de Colombie et l'UNOOSA ont signé un accord de coopération pour établir un Bureau Régional de Soutien de UN-SPIDER en 2011. L'IGAC encourage l'utilisation d'informations spatiales en Colombie à diverses fins et soutient ONU-SPIDER dans les activités menées en Amérique Latine et dans les Caraïbes. En tant que BRA, l'IGAC continue de fournir des experts pour le soutien consultatif technique de ONU-SPIDER aux pays de la région et de contribuer aux efforts de renforcement des capacités dans la région.

  •  

     

     

Term Parents

UN-SPIDER Regional Support Offices with hazard-specific expertise