Tectonic plates are pieces of Earth's crust and upper mantle called the lithosphere and are about 100 km thick. There are two main types of plates: oceanic and continental, each composed of different materials. The formation and movement of these plates generates everything from the shape and orientation of continents to the mountains and trenches on Earth. The plates layer shows major and minor plates. Microplates are not included in this map. This version of the tectonic plates and boundaries was derived from Peter Bird in Geochemistry Geophysics Geosystems, 4(3), 1027, [doi:10.1029/2001GC000252]. The full publication can be read here. Processing of the 2014 version of the data into GIS formats was done by Hugo Ahlenius.

The global tectonics data compilation is a set of raster and vector data that are useful for investigating tectonics past and present. The datasets are useful on their own or can be used in GIS software, which includes the QGIS project file for convenience. The datasets include our new models for tectonic plate boundaries and deformation zones, geologic provinces and orogens. Additional datasets include earthquake and volcano locations, geochronology, topography, magnetics, gravity, and seismic velocity.

The global tectonics collection is suitable for research and educational purposes.

The Earth’s lithosphere is made up of a series of plates that float on the mantle. Scientists think the convection of the mantle causes these plates to move triggering earthquakes, volcanoes, mountain-building events, or trench formation. These plates creep along at a rate of approximately five to ten centimeters (two to four inches) per year. These plates move in primarily three main ways. They slide past one another along transform (strike-slip) boundaries, they push against each other at convergent boundaries, or pull away in opposite directions at divergent boundaries. Each one of these interactions create different types of landforms. For example, the steady pressure of the Indian Plate and the Eurasian Plate built the Himalaya mountains and the Plateau of Tibet. The divergent boundary between the African Plate and the Arabian formed the Red Sea.Use this plate map layer to explore how the movement of the plates cause earthquakes, volcanoes, or shape Earth’s landscape.

This map layer features both major and minor plates, but excludes microplates. The data is from the scientific study by Peter Bird published in volume 4, issue 3 of Geochemisty, Geophysics, Geosystems and was translated into geospatial formats by Hugo Ahlenius and updated by Dan Pisut.

117 original plate boundaries from Esri Data and Maps (2007) edited to better match 10 years of earthquakes, land forms and bathymetry from Mapping Our World's WSI_Earth image from module 2. Esri Canada's education layer of plate boundaries and the Smithsonian's ascii file from the download section of the 'This Dynamic Planet' site plate boundaries were used to compare the resulting final plate boundaries for significant differences.

The surface of the Earth is broken up into large plates. There are seven major plates: North America, South America, Eurasia, Africa, India, the Pacific, and Antarctica. There are also numerous microplates. The number and shapes of the plates change over geologic time. Plates are divided by boundaries that are seismically active. The different plate boundaries can be described by the type of motion that is occurring between the plates at specific locations. Ocean basins contain spreading ridges where the youngest portions of the seafloor are found. At the spreading ridges magma is released as it pushes up from the mantle and new oceanic crust is formed. At subduction zone boundaries plates are moving toward each other, with one plate subducting or moving beneath the other. When this occurs the crust is pushed into the mantle where it is recycled into magma.Data accessed from here: https://www-udc.ig.utexas.edu/external/plates/data.htm

The NLWv3 Tectonic Plates layer contains features are produced based on assigning each NLWv3 landform feature the topmost tectonic plate and then using ArcGIS's Dissolve geoprocessing tool to create multipart polygons representing regions of each of the topmost plates.Tectonic plates are the building blocks of continents and comprise the Earth's crust. Tectonic plates float, moving slowly in the outer layers of the Earth's mantle. Tectonic plates cover the entire Earth's surface and their respective movements creates three types of boundaries: Divergent: The plates are moving away from each other causing new crust to emerge. Such boundaries are usually referred to as rift zones.Convergent: The plates are colliding in one of two ways. The first is when the edges of both plates uplift to cause mountains to rise and the second is subducting where one plate slides beneath the other, causing it to rise. Transform: These plates slide past each other in opposite directions.The boundaries of tectonic plates are where earthquakes, most volcanoes, and rough mountainous terrain are produced. We evaluated the most recently produced digital tectonic plate boundary datasets. The NLWv3 compilation is first based on Ahlenius and then we adjusted many of the boundaries to match more recent seafloor rift and landform boundaries. We also added the Sinai and Adriatic Sea plates. Ahlenius, H. 2014. World tectonic plates and boundaries. Accessed December 22, 2021. https://github.com/fraxen/tectonicplatesTectonic map of the world. Accessed April 5, 2022. https://www.datapages.com/gis-map-publishing-program/gis-open-files/global-framework/tectonic-map-of-the-world-2007.Bird, P. 2003. An updated digital model of plate boundaries. Geochemistry, Geophysics, Geosystems 4 (3):1–46. doi: 10.1029/2001GC000252.Gaba, E. 2018. Tectonic plates boundaries World Map Wt 180degE centered-en.svg. Accessed June 2, 2022. https://en.wikipedia.org/wiki/File:Tectonic_plates_boundaries_World_map_Wt_180degE_centered-en.svgHasterok, D., J. A. Halpin, A. S. Collins, M. Hand, C. Kreemer, M. G. Gard, and S. Glorie. 2022. New maps of global geological provinces and tectonic plates. Earth-Science Reviews 231:104069. doi: 10.1016/j.earscirev.2022.104069.

This layer shows the interpreted surface locations of active plate and microplate boundaries, in and around Te Riu-a-Māui / Zealandia. The layer was newly-compiled for, and is part of, the 'Tectonic map of Te Riu-a-Māui / Zealandia' 1:8 500 000 dataset.

A web application for use in explaining the global distribution of earthquakes and volcanoes and why they are located where they are - specifically designed for use with NCEA Level 1 Geography.Layers that can be turned on in this application:- Tectonic Plate Boundaries- Recent Earthquakes- Archived Earthquakes- Global VolcanoesStudents can export their maps to a PDF or screenshot their maps.You do not have to have an ArcGIS Schools Bundle to access this web application.

A seismotectonic map shows geologic, seismological, and other information that is pertinent to seismic hazards but previously was scattered among many sources. Afghanistan is part of the Eurasian plate. Afghan seismicity is driven by the relative northward movements of the Arabian plate past western Afghanistan at 33 mm/yr and of the Indian plate past eastern Afghanistan at 39 mm/yr or faster as both plates subduct under Eurasia. Afghanistan is laced with faults. Known faults large enough to have been mapped at a scale of 1:500,000 are least abundant in the stable North Afghan platform, more abundant in the accreted terranes of southern Afghanistan, and most likely to slip rapidly and generate earthquakes in eastern and southeastern Afghanistan in the broad transpressional plate boundary with the Indian plate. Crustal earthquakes are most abundant in and around northeastern Afghanistan as a result of the northward subduction of the Indian plate. Crustal earthquakes are somewhat less abundant in much of the transpressional plate boundary with India. Central and western Afghanistan are least seismically active. Beneath the Hindu Kush of northeastern Afghanistan and the Pamirs of adjacent Tajikistan, numerous mantle earthquakes occur within a steeply dipping, northeast-trending, tabular zone that is 700 km long and extends nearly to 300 km depth. Except for the Chaman fault that forms part of the western edge of the transpressional plate boundary in Pakistan and Afghanistan, published evidence for or against the activity of individual Afghan faults is sparse.

[Summary provided by the USGS.]

This layer identifies the location of plate boundaries and the corresponding names to the major tectonic plates of Earth.

The SAR4Tectonics project aims to provide open-access, global measurements of ground deformation in high-strain areas near tectonic plate boundaries. By leveraging the capabilities of the Persistent and Distributed Scatterer (PS/DS) technique with Sentinel-1 SAR images, the project seeks to deliver comprehensive and accurate data on ground deformation, which is crucial for understanding geological processes, assessing seismic risks in these regions, and advance our understanding of Earth's dynamic processes in general. The PS/DS technique offers significantly denser spatial coverage than GNSS, enabling the detection of more localized deformation signals. For the first time, such a vast and detailed dataset is made publicly available. By making this data openly accessible, the SAR4Tectonics project hopes to reduce the burden of SAR data processing for geoscientists, facilitating future studies.The project involved processing 6.5 years of SAR data, focusing on areas where the second invariant of strain exceeds 3 nanostrain per year. Various error corrections were employed, including tropospheric delay correction using ECMWF reanalysis data, ionospheric mitigation via CODE total electron content maps, and solid earth tide modeling. Additionally, the impact of vegetation and soil moisture on distributed scatterers was minimized through a full covariance matrix (phase linking) approach, and the results were calibrated using GNSS data. The final dataset includes line-of-sight average velocity maps, deformation time series, projection vectors, and reference plate modeled velocities.

The USGS presents an updated model of the Juan de Fuca slab beneath southern British Columbia, Washington, Oregon, and northern California, and use this model to separate earthquakes occurring above and below the slab surface. The model is based on depth contours previously published by Flück and others (1997). Our model attempts to rectify a number of shortcomings in the original model and to update it with new work. The most significant improvements include (1) a gridded slab surface in geo-referenced (ArcGIS) format, (2) continuation of the slab surface to its full northern and southern edges, (3) extension of the slab surface from 50-km depth down to 110-km beneath the Cascade arc volcanoes, and (4) revision of the slab shape based on new seismic-reflection and seismic-refraction studies. We have used this surface to sort earthquakes and present some general observations and interpretations of seismicity patterns revealed by our analysis. In addition, we provide files of earthquakes above and below the slab surface and a 3-D animation or fly-through showing a shaded-relief map with plate boundaries, the slab surface, and hypocenters for use as a visualization tool.

[Summary provided by the USGS.]

Named Landforms of the World version 2 (NLWv2) contains four sub-layers representing geomorphological landforms, provinces, divisions, and their respective cartographic boundaries. The latter supports map making, while the first three represent basic units, such as landforms, which comprise provinces, and provinces comprise divisions. NLW is a substantial update to World Named Landforms in both compilation method and the attributes that describe each landform. For more details, please refer to our paper, Named Landforms of the World: A Geomorphological and Physiographic Compilation, in Annals of the American Association of Geographers. July 2, 2025: We have made Named Landforms of the World v3 (NLWv3) available. Please explore this group containing all of the layers and data. NLWv2 will remain available. Landforms are commonly defined as natural features on the surface of the Earth. The National Geographic Society specifies terrain as the basis for landforms and lists four major types: mountains, hills, plateaus, and plains. Here, however, we define landforms in a richer way that includes properties relating to underlying geologic structure, erosional and depositional character, and tectonic setting and processes. These characteristics were asserted by Dr. Richard E. Murphy in 1968 in his map, titled Landforms of the World. We blended Murphy"s definition for landforms with the work E.M. Bridges, who in his 1990 book, World Geomorphology, provided a globally consistent description of geomorphological divisions, provinces, and sections to give names to the landform regions of the world. AttributeDescriptionBridges Full NameFull name from E.M. Bridges" 1990 "World Geomorphology" Division and if present province and section - intended for labeling print maps of small extents. Bridges DivisionGeomorphological Division as described in E.M. Bridges" 1990 "World Geomorphology" - All Landforms have a division assigned, i.e., no nulls. Bridges ProvinceGeomorphological Province as described in E.M. Bridges" 1990 "World Geomorphology" - Not all divisions are subdivided into provinces. Bridges SectionGeomorphological Section as described in E.M. Bridges" 1990 "World Geomorphology" - Not all provinces are subdivided into sections.StructureLandform Structure as described in Richard E. Murphy"s 1968 "Landforms of the World" map. Coded Value Domain. Values include: - Alpine Systems: Area of mountains formed by orogenic (collisions of tectonic plates) processes in the past 350 to 500 million years. - Caledonian/Hercynian Shield Remnants: Area of mountains formed by orogenic (collisions of tectonic plates) processes 350 to 500 million years ago. - Gondwana or Laurasian Shields: Area underlaid by mostly crystalline rock formations fromed one billion or more years ago and unbroken by tectonic processes. - Rifted Shield Areas: fractures or spreading along or adjacent to tectonic plate edges. - Isolated Volcanic Areas: volcanic activity occurring outside of Alpine Systems and Rifted Shields. - Sedimentary: Areas of deposition occurring within the past 2.5 million years Moist or DryLandform Erosional/Depositional variable as described in Richard E. Murphy"s 1968 "Landforms of the World" map. Coded Value Domain. Values include: - Moist: where annual aridity index is 1.0 or higher, which implies precipitation is absorbed or lost via runoff. - Dry: where annual aridity index is less than 1.0, which implies more precipitation evaporates before it can be absorbed or lost via runoff. TopographicLandform Topographic type variable as described in Richard E. Murphy"s 1968 "Landforms of the World" map. Karagulle et. al. 2017 - based on rich morphometric characteristics. Coded Value Domain. Values include: - Plains: Areas with less than 90-meters of relief and slopes under 20%. - Hills: Areas with 90- to 300-meters of local relief. - Mountains: Areas with over 300-meters of relief - High Tablelands: Areas with over 300-meters of relief and 50% of highest elevation areas are of gentle slope. - Depressions or Basins: Areas of land surrounded land of higher elevation. Glaciation TypeLandform Erosional/Depositional variable as described in Richard E. Murphy"s 1968 "Landforms of the World" map. Values include: - Wisconsin/Wurm Glacial Extent: Areas of most recent glaciation which formed 115,000 years ago and ended 11,000 years ago. - Pre-Wisconsin/Wurm Glacial Extent: Areas subjected only to glaciation prior to 140,000 years ago. ContinentAssigned by Author during data compilation. Bridges Short NameThe name of the smallest of Division, Province, or Section containing this landform feature. Murphy Landform CodeCombination of Richard E. Murphy"s 1968 "Landforms of the World" variables expressed as a 3- or 4- letter notation. Used to label medium scale maps. Area_GeoGeodesic area in km2. Primary PlateName of tectonic plate that either completely underlays this landform feature or underlays the largest portion of the landform"s area.Secondary PlateWhen a landform is underlaid by two or more tectonic plates, this is the plate that underlays the second largest area.3rd PlateWhen a landform is underlaid by three or more tectonic plates, this is the plate that underlays the third largest area.4th PlateWhen a landform is underlaid by four or more tectonic plates, this is the plate that underlays the fourth largest area.5th PlateWhen a landform is underlaid by five tectonic plates, this is the plate that underlays the fifth largest area.NotesContains standard text to convey additional tectonic process characteristics. Tectonic ProcessAssigns values of orogenic, rift zone, or above subducting plate. These data are also available as an ArcGIS Pro Map Package: Named_Landforms_of_the_World_v2.0.mpkx.These data supersede the earlier v1.0: World Named Landforms. Change Log:DateDescription of ChangeJuly 20, 2022Corrected spelling of Guiana from incorrect representation, "Guyana", used by Bridges.July 27, 2022Corrected Structure coded value domain value, changing "Caledonian/Hercynian Shield" to "Caledonian , Hercynian, or Appalachian Remnants". Cite as: Frye, C., Sayre R., Pippi, M., Karagulle, Murphy, A., D. Soller, D.R., Gilbert, M., and Richards, J., 2022. Named Landforms of the World. DOI: 10.13140/RG.2.2.33178.93129. Accessed on:

The PALEOMAP project produces paleogreographic maps illustrating the Earth's plate tectonic, paleogeographic, climatic, oceanographic and biogeographic development from the Precambrian to the Modern World and beyond.

A series of digital data sets has been produced consisting of plate tectonic data, climatically sensitive lithofacies, and biogeographic data. Software has been devloped to plot maps using the PALEOMAP plate tectonic model and digital geographic data sets: PGIS/Mac, Plate Tracker for Windows 95, Paleocontinental Mapper and Editor (PCME), Earth System History GIS (ESH-GIS), PaleoGIS(uses ArcView), and PALEOMAPPER.

Teaching materials for educators including atlases, slide sets, VHS animations, JPEG images and CD-ROM digital images.

Some PALEOMAP products include: Plate Tectonic Computer Animation (VHS) illustrating motions of the continents during the last 850 million years.

Paleogeographic Atlas consisting of 20 full color paleogeographic maps. (Scotese, 1997).

Paleogeographic Atlas Slide Set (35mm)

Paleogeographic Digital Images (JPEG, PC/Mac diskettes)

Paleogeographic Digital Image Archive (EPS, PC/Mac Zip disk) consists of the complete digital archive of original digital graphic files used to produce plate tectonic and paleographic maps for the Paleographic Atlas.

GIS software such as PaleoGIS and ESH-GIS.

This map service depicts the boundaries of the Earth's major tectonic plates and fault lines.Tectonic plates are large plates of rock that make up the foundation of the Earth's crust and the shape of the continents. The plates comprise the bottom of the crust and the top of the Earth's mantle. The plates are most famously known for being the source of earthquakes.A fault is a fracture or discontinuity in a volume of rock, across which there has been significant displacement as a result of earth movement. Large faults within the Earth's crust result from the movement of tectonic plates. Map Service published and hosted by Esri Canada © 2012. Content Source(s): Plates, United States Geological Survey (USGS)Fault Lines, United States Geological Survey(USGS) Coordinate System: Web Mercator Auxiliary Sphere (WKID 102100) Publication Date: January, 2012 Update Frequency: As Required REST URL for ArcGIS Web APIs: http://edumaps.esricanada.com/ArcGIS/rest/services/MapServices/TectonicPlates/MapServer WMS API URL: http://edumaps.esri.ca/ArcGIS/services/MapServices/TectonicPlates/MapServer/WMSServerKML (Google) URL: http://edumaps.esricanada.com/ArcGIS/rest/services/MapServices/TectonicPlates/MapServer/generatekml

The 'Major crustal boundaries of Australia' map synthesizes more than 30 years of acquisition of deep seismic reflection data across Australia, where major crustal-scale breaks have been interpreted in the seismic reflection profiles, often inferred to be relict sutures between different crustal blocks. The widespread coverage of the seismic profiles now provides the opportunity to construct a map of major crustal boundaries across Australia. Starting with the locations of the crustal breaks identified in the seismic profiles, geological (e.g. outcrop mapping, drill hole, geochronology, isotope) and geophysical (e.g. gravity, aeromagnetic, magnetotelluric) data are used to map the crustal boundaries, in map view, away from the seismic profiles. For some of these boundaries, a high level of confidence can be placed on the location, whereas the location of other boundaries can only be considered to have medium or low confidence. In other areas, especially in regions covered by thick sedimentary successions, the locations of some crustal boundaries are essentially unconstrained. The 'Major crustal boundaries of Australia' map shows the locations of inferred ancient plate boundaries, and will provide constraints on the three dimensional architecture of Australia. It allows a better understanding of how the Australian continent was constructed from the Mesoarchean through to the Phanerozoic, and how this evolution and these boundaries have controlled metallogenesis. It is best viewed as a dynamic dataset, which will have to be further refined and updated as new information such as seismic reflection data becomes available.

The Long Valley Caldera GIS Database provides an overview of the studies being conducted by the Long Valley Observatory in eastern California from 1975 to 2001. The database includes geologic, monitoring, and topographic datasets related to Long Valley caldera. The CD-ROM contains a scan of the original geologic map of the Long Valley region by R. Bailey. Real-time data of the current activity of the caldera (including earthquakes, ground deformation and the release of volcanic gas), information about volcanic hazards and the USGS response plan are available online at the Long Valley observatory web page (http://lvo.wr.usgs.gov). If you have any comments or questions about this database, please contact the Scientist in Charge of the Long Valley observatory.

[Summary provided by the USGS.]

This part of DS 781 presents data for faults for the geologic and geomorphic map of the Offshore of Fort Ross map area, California. The vector data file is included in "Faults_OffshoreFortRoss.zip," which is accessible from http://pubs.usgs.gov/ds/781/OffshoreFortRoss/data_catalog_OffshoreFortRoss.html. The Offshore of Fort Ross map area is cut by the northwest-trending San Andreas Fault, the right-lateral transform boundary between the North American and Pacific tectonic plates. The San Andreas extends across the inner shelf in the southern part of the map, then crosses the shoreline at Fort Ross and continues onland for about 75 km to the east flank of Point Arena (fig. 8-1). Seismic-reflection data are used to map the offshore fault trace, and reveal a relatively simple, 200- to 500-m wide zone typically characterized by one or two primary strands. About 1500 m west of the San Andreas Fault, the mid shelf (between water depths of 40 m and 70 m) in the southernmost part of the map area includes an about 5-km-wide field of elongate, shore-normal sediment lobes (unit Qmsl). Individual lobes within the field are as much as 650-m long and 200-m wide, have as much as 1.5 m (check with Steve) of relief above the surrounding smooth seafloor, and are commonly connected with upslope chutes. Given their morphology and proxmity to the San Andreas fault, we infer that these lobes result from slope failures associated with strong ground motions triggered by large San Andreas earthquakes. Movement on the San Andreas has juxtaposed different coastal bedrock blocks (Blake and others, 2002). Rocks east of the fault that occur along the coast and in the nearshore belong to the late Tertiary, Cretaceous, and Jurassic Franciscan Complex, either sandstone of the Coastal Belt or Central Belt (unit TKfs) or melange of the central terrane (unit fsr). Bedrock west of the fault are considered part of the Gualala Block (Elder, 1998) and include the Eocene and Paleocene German Rancho Formation (unit Tgr) and the Miocene sandstone and mudstone of the Fort Ross area (unit Tsm). This section of the San Andreas Fault onland has an estimated slip rate of about 17 to 25 mm/yr (Bryant and Lundberg, 2002). The devastating Great 1906 California earthquake (M 7.8) is thought to have nucleated on the San Andreas Fault about 100 kilometers south of this map area offshore of San Francisco (e.g., Bolt, 1968; Lomax, 2005), with the rupture extending northward through the Offshore of Fort Ross map area to the south flank of Cape Mendocino. Emergent marine terraces along the coast in the Offshore of Fort Ross map area record recent contractional deformation associated with the San Andreas Fault system. Prentice and Kelson (2006) report uplift rates of 0.3 to 0.6 mm/yr for a late Pleistocene terrace exposed at Fort Ross, and this recent uplift must also have affect the nearshore and inner shelf. Previously, McCulloch (1987) mapped a nearshore (within 3 to 5 km of the coast) fault zone from Point Arena to Fort Ross (Fig. 8-1) using primarily deeper industry seismic-reflection data. Subsequently, Dickinson and others (2005) named this structure the "Gualala Fault." Our mapping, also based on seismic-reflection data, reveals this structure as a steep, northeast trending fault and similarly shows the fault ending to the south in the northern part of the Offshore of Fort Ross map area. We have designated the zone of faulting and folding above this structure the "Gualala Fault deformation zone." Faults were primarily mapped by interpretation of seismic reflection profile data (see field activity S-8-09-NC). The seismic reflection profiles were collected between 2007 and 2010. References Cited Blake, M.C., Jr., Graymer, R.W., and Stamski, R.E., 2002, Geologic map and map database of western Sonoma, northernmost Marin, and southernmost Mendocino counties, California: U.S. Geological Survey Miscellaneous Field Studies Map 2402, scale 1:100,000. Bolt, B.A., 1968, The focus of the 1906 California earthquake: Bulletin of the Seismological Society of America, v. 58, p. 457-471. Bryant, W.A., and Lundberg, M.M., compilers, 2002, Fault number 1b, San Andreas fault zone, North Coast section, in Quaternary fault and fold database of the United States: U.S. Geological Survey website, accessed April 4, 2013, at http://earthquakes.usgs.gov/hazards/qfaults. Dickinson, W.R., Ducea, M., Rosenberg, L.I., Greene, H.G., Graham, S.A., Clark, J.C., Weber, G.E., Kidder, S., Ernst, W.G., and Brabb, E.E., 2005, Net dextral slip, Neogene San Gregorio-Hosgri Fault Zone, coastal California: Geologic evidence and tectonic implications: Geological Society of America Special Paper 391, 43 p. Elder, W.P., ed., 1998, Geology and tectonics of the Gualala Block, northern California: Pacific Section, Society of Economic Paleontologists and Mineralogists, Book 84, 222 p. Lomax, A., 2005, A reanalysis of the hypocentral location and related observations for the Great 1906 California earthquake: Bulletin of the Seismological Society of America, v. 95, p. 861-877. McCulloch, D.S., 1987, Regional geology and hydrocarbon potential of offshore central California, in Scholl, D.W., Grantz, A., and Vedder, J.G., eds., Geology and Resource Potential of the Continental Margin of Western North America and Adjacent Oceans -- Beaufort Sea to Baja California: Houston, Texas, Circum-Pacific Council for Energy and Mineral Resources, Earth Science Series, v. 6., p. 353-401. Prentice, C.S., and Kelson, K.I., 2006, The San Andreas fault in Sonoma and Mendocino counties, in Prentice, C.S., Scotchmoor, J.G., Moores, E.M., and Kiland, J.P., eds., 1906 San Francisco Earthquake Centennial Field Guides: Field trips associated with the 100th Anniversary Conference, 18-23 April 2006, San Francisco, California: Geological Society of America Field Guide 7, p. 127-156.

The World Stress Map (WSM) is the global compilation of information on the present-day stress field in the Earth's crust. The current WSM database release 2016 (Heidbach et al., 2016) has 42,870 data records, but the data are unevenly distributed and clustered.To analyse the wave-length of the crustal stress pattern of the orientation of maximum horizontal stress Shmax, we use so-called smoothed stress maps that show the mean SHmax orientation on regular grids. The mean SHmax orientation is estimated with the Matlab® script stress2grid (Ziegler and Heidbach, 2017) which is based on the statistics of bi-polar data. The script provides two different approaches to calculate the mean SHmax orientation on regular grids.The first is using a constant search radius around the grid point and computes the mean SHmax orientation if sufficient data records are within the given fixed search radius. This can result in mean SHmax orientations with a high standard deviation of the individual mean SHmax orientation and it may hide local perturbations. Thus, the mean SHmax orientation is not necessarily reliable for a local stress field analysis.The second approach is using variable search radii and determines the search radius for which the standard deviation of the mean SHmax orientation is below a user-defined threshold. This approach delivers the mean SHmax orientations with a user-defined degree of reliability. It resolves local stress perturbations and is not available in areas with no data or conflicting information that result in a large standard deviation.The search radius starts with 1000 km and is decreased in 100 km steps down to 100 km. Mean SHmax orientation is taken and plotted here for the largest search radius when the standard deviation of the mean SHmax orientation at the individual grid points is smaller than 25°. For the estimation of the mean Shmax we selected the following data: A-C quality data without PBE flag.Furthermore, only data records located on the same tectonic plate as the grid point is used to calculate the mean SHmax orientation. Minimum number of data records within the search radius is n = 5 and data records within a distance of d ≤ 200 km to the nearest plate boundary are not used. Plate boundaries are taken from the global model PB2002 from Bird (2003).Furthermore, a distance and data quality weight is applied; the distance threshold is set to 10% of the search radius. We provide the resulting smoothed stress data for four global grids (0.2°, 0.5°, 1°, and 2° grid spacing) using two fixed search radii (250 and 500 km) and the approach with variable search radii. Details on the format of the data files with the mean SHmax orientation are provided in the 2018-002_readme file.