Earthquakes today

Current and latest world earthquakes breaking news, activity and articles today

Geological news

Landsat Adds to World Memory


Landsat Adds to World Memory

A United Nations group established to preserve humanity’s documentary history has selected a portion of the U.S. Geological Survey (USGS) Landsat archive of Earth imagery to be added to the Memory of the World International Register. 

“During a span of almost 40 years, the Landsat series of Earth observation satellites has become a unique reference worldwide for advancing our scientific knowledge and our understanding of terrestrial systems,” said Anne Castle, Assistant Secretary for Water and Science, U.S. Department of the Interior.  “The inclusion of the Landsat data archive in the Memory of the World Register is recognition of the incredible value of this long term data collection, not only for its contribution to scientific research but also for its rich international cultural value.” 

A joint initiative between USGS and NASA, the Landsat program of Earth observation provides a vital information resource for applications in agriculture, geology, forestry, water resources, regional planning, mapping, emergency response, and global change research.

The Memory of the World Programme, administered through the United Nations Educational, Scientific and Cultural Organization (UNESCO), selected the Landsat Multispectral Scanner (MSS) dataset because it is a unique, irreplaceable record of the Earth’s land surfaces, shallow coastal regions, and reefs.  Compiled between 1972 and 1992, this collection of images from across the globe includes over 600,000 scenes, each covering approximately 100 by 100 miles.  The continuous data record reveals both gradual change, as in glacier movement or coastline erosion, and sudden change, as in forest clear-cuts, wild land fires, or seasonal floods. 

Remotely sensed Landsat images are not just pictures, but contain many layers of data collected at different points along the visible and invisible light spectrum. A single Landsat scene taken from 400 miles above the Earth can accurately detail the condition of hundreds of thousands of acres of grassland, agricultural crops, or forests. 

The award citation proclaims, “The inclusion of this documentary heritage in the Memory of the World Register reflects its exceptional value and signifies that it should be protected for the benefit of all humanity.” 

The full USGS archive holds over three million scenes obtained continuously from July 1972 to today by a series of six Landsat satellites. Since 2008, when the images became available free of charge and downloadable from the internet, there has been a burst of innovative science applications of Landsat data. 

“The universal availability of the Landsat data at no charge is a key to its unique capabilities and global scope,” Castle continued. “Scientists, land managers, and students everywhere can work with long term, accurate, unbiased, and freely accessible data to confront the most difficult challenges involving land use, natural resources, and the environment.”

Gallery of selected Landsat images: World Events as Seen from Space

Further information about Landsat

USGS Newsroom


More information

Parameter Value Description
Magnitude mb The magnitude for the event.
Longitude ° East Decimal degrees longitude. Negative values for western longitudes.
Latitude ° North Decimal degrees latitude. Negative values for southern latitudes.
Depth km Depth of the event in kilometers.
Place Textual description of named geographic region near to the event. This may be a city name, or a Flinn-Engdahl Region name.
Time 1970-01-01 00:00:00 Time when the event occurred. UTC/GMT
Updated 1970-01-01 00:00:00 Time when the event was most recently updated. UTC/GMT
Timezone offset Timezone offset from UTC in minutes at the event epicenter.
Felt The total number of felt reports
CDI The maximum reported intensity for the event.
MMI The maximum estimated instrumental intensity for the event.
Alert Level The alert level from the PAGER earthquake impact scale. Green, Yellow, Orange or Red.
Review Status Indicates whether the event has been reviewed by a human.
Tsunami This flag is set to "1" for large events in oceanic regions and "0" otherwise. The existence or value of this flag does not indicate if a tsunami actually did or will exist.
SIG A number describing how significant the event is. Larger numbers indicate a more significant event.
Network The ID of a data contributor. Identifies the network considered to be the preferred source of information for this event.
Sources A comma-separated list of network contributors.
Number of Stations Used The total number of Number of seismic stations which reported P- and S-arrival times for this earthquake.
Horizontal Distance Horizontal distance from the epicenter to the nearest station (in degrees).
Root Mean Square sec The root-mean-square (RMS) travel time residual, in sec, using all weights.
Azimuthal Gap The largest azimuthal gap between azimuthally adjacent stations (in degrees).
Magnitude Type The method or algorithm used to calculate the preferred magnitude for the event.
Event Type Type of seismic event.
Event ID Id of event.
Event Code An identifying code assigned by, and unique from, the corresponding source for the event.
Event IDS A comma-separated list of event ids that are associated to an event.

Leave a Reply