DESCRIPTION OF FIELDS IN THE MACKENZIE LANDSLIDE DATABASE Note: Not all fields appear in all databases. Column FIELD NAME AND DESCRIPTION. 1 LANDSLIDE IDENTIFICATION; Unique ID#: This is a unique identification number, applicable throughout all three databases (northern, central, and southern). This is the identification to use in any future reference. 2 LANDSLIDE IDENTIFICATION; NTS ID#: This is the landslide number assigned by the author during compilation of some portion of the database and is retained here as a connection to the original manuscript maps and photos. It is not recommended for use in any future reference. 3 LANDSLIDE IDENTIFICATION; NTS#: National Topographic Series (NTS) map sheet number (1:250 000 scale) for the area in which the landslide occurs. 4 LANDSLIDE LOCATION; Latitude: Latitude of the centre of the landslide scar, in degrees, minutes, and seconds north. A space separates the degrees, minutes, and seconds (i.e. 64 47 30). 5 LANDSLIDE LOCATION; Longitude: Longitude of the centre of the landslide scar, in degrees, minutes, and seconds west. A space separates the degrees, minutes, and seconds (i.e.132 33 30). 6 LANDSLIDE LOCATION; Location: A brief description of the location of the landslide (i.e. W bank, Liard R). 7 LANDSLIDE LOCATION; Site: A brief description of the site (i.e. valley slope, ravine, top of valley, river bank, lakeshore, coast, etc). 8 LANDSLIDE LOCATION; Scar elevation: Approximate elevation of landslide scar (usually estimated from topographic map). In the case of a cluster of landslides, a range of elevations may be indicated. 9 LANDSLIDE NATURE; S/M/C: Indicates whether the unique ID number represents a single (S) landslide, multiple (M) landslides, or a landslide complex (C). 'Single' (S) indicates that one distinct landslide feature is represented by the unique landslide number in the database. It is recognized that the single landslide may represent several distinct failures over time but it is still a distinct feature. (i.e. A retrogressive thaw-flow slide is subject to continual headward melting, enlarging over time. A rotational slide may consist of a number of retrogressive rotational blocks which may not have occurred concurrently.) 'Multiple' (M) indicates that a cluster of landslides is represented by the unique landslide number (i.e. where several distinct retrogressive thaw-flow slides are found in a relatively small area). Size measurements represent the average landslide in the cluster. In a few cases, the individual slides could not be separated and the size measurement refers to the size of the group; in this case, a note is made in 'comments' (field 24). 'Complex' (C) indicates an area of coalescing or overlapping landslides representing different events that can not be separated (i.e. a group of new flows inside a larger, old scar, or several flows that have grown laterally along a scarp into one big complex, or a series of adjacent and intersecting block failures representing individual, unrelated events of different times). 10 LANDSLIDE NATURE; # of landslides: Number or estimated number of landslides that are grouped as a 'multiple' or 'complex' (field 9) under one unique ID number. 11 LANDSLIDE NATURE; Class: Landslide class has 2 major categories, landslides in which the failure plane occurred in unconsolidated sediments" (Q) and those in which the failure plane occurred in bedrock (R). Class is then subdivided according to main failure mechanism. 'Flow' (F) has a fluid character, showing evidence of mobility throughout the failure. 'Slide' (S) shows evidence of rigid movement in that components of the slide move downslope in a more or less intact manner as a block or series of blocks. 'Topple' (T), the forward rotation of a mass due to gravity, is too small to be identified from airphotos and, although common in the field, is rarely included in the inventory. 'Complex' (Cplx) is assigned when more than one type of movement is present in the landslide and each movement makes up a significant volume of the present landslide. Two mechanisms of failure may be active at the same time in an individual landslide, or, as a landslide develops, one type of failure may evolve into another type. 'Unclassified' (U) is assigned when the failure mechanism is unknown. 12 LANDSLIDE NATURE; Type: Type is a further subdivision of the major failure mechanisms of Class (field 11) and the categories are described below in relation to the appropriate class. Types associated with melting of frozen ground and/or ground ice, and therefore unique to permafrost regions, are named following common permafrost terminology. Class: Flow: Types: Active layer detachment (ALDS) is a shallow version of earthflow unique to permafrost areas. The seasonal thaw layer (active layer), including the vegetation mat, flows downslope in a shallow, long, narrow tongue of water-saturated sediment on the underlying frozen sediment. It commonly follows disturbance of the insulating vegetation mat. Also known as skin flow. May develop into a retrogressive thaw flow or debris flow. Retrogressive thaw flow (RTFS) is an earthflow unique to permafrost areas. Flow morphology is bimodal, with a steep head scarp and low angle tongue. The retrogressive nature of the flow is due to continual melting of newly exposed ground ice and icy sediment in the headscarp. Also known as bimodal flow or ground ice slump. Debris flow (Debris flow) is a rapid flow of sediment downslope and is characterized by a long, narrow tongue with a fan-shaped terminus. Class: Slide: Types: Rotational slide (Rotational slide) involves the downslope movement of a rigid block of sediment along a curving failure surface, such that the toe of the block extends well beyond the original slope and the original upper surface of the block is generally back-tilted towards the scarp of the landslide. Such failures may occur as an individual block or as a stepped series of blocks associated with successive failures. Translational slide (Translational slide) involves the downslope movement of a rigid block of sediment along a planar failure surface, commonly a bedrock bedding plane. Active layer detachment (ALDS) is a special version of translational slide unique to permafrost areas. The seasonally active layer slides downslope in a relatively rigid manner on the underlying frozen sediment. Also known as an active layer glide. Not distinguished from the shallow earthflow in this database. Class: Topple: Types: No subdivision. Class: Complex: Types: Rotational slide-retrogressive thaw flow (Rotational slide-RTFS). This type of failure exhibits characteristics that are gradational between those of slides and those of flows. The movement may have originally failed as a series of rotational block slides, however, much or all of the ongoing movement then consists of flow associated with thawing of icy sediments. These features are commonly retrogressive. Active layer detachment-debris flow complex (ALDS-debris flow) is assigned when the failure exhibits characteristics that are gradational between shallow detachments and deeper debris flows. Active layer detachment flows or slides may evolve into debris flows ( or retrogressive thaw flows) when underlying icy sediment is exposed and melts following removal of the active layer. Class: Unclassified: Types: 1. Not examined, but its existence is known from published work or it is newly reported. 2. Unable to classify 3. Unable to distinguish feature on airphoto, but it is cited in published work. 13 LANDSLIDE DESCRIPTION; Width: Average width of landslide in metres 14 LANDSLIDE DESCRIPTION; Length: Average length from headscarp to toe of landslide in metres 15 LANDSLIDE DESCRIPTION; Area: Area includes the landslide scar and spoil areas and is a calculation of width x length (sq. m) 16 LANDSLIDE DESCRIPTION; Aspect (degrees): The direction that the scar faces in degrees relative to true north. In cases of clusters of landslides a range of directions are given. 17 LANDSLIDE DESCRIPTION; Aspect (direction): Descriptive direction that the scar faces i.e. SW. In cases of clusters of landslides a range of directions are given. 18 GEOLOGY; Genesis: Genetic class of pre-slide material, from GSC surficial geology map. (i.e. till, moraine, lacustrine, alluvial, glaciolacustrine, glaciofluvial, colluvial, rock) 19 GEOLOGY; Lithology: Texture characteristics of pre-slide unconsolidated sediment (in order of estimated volume if several texture sizes present), or lithology of bedrock in case of rockslides. (i.e. clay, sand, till, shale, dolomite) Bedrock lithology is derived from published geology maps.May be unknown and left blank. 20 GEOLOGY; map unit: This field contains the appropriate label, copied as printed, from the source unit on the Geological Survey of Canada surficial geology map. It is left blank if known to be not applicable or incorrect. With one exception, it is copied as shown on the map. Because Excel can not handle a label containing a horizontal line separating 2 parts, the meaning "over" is entered in the database as //. (i.e. sEr//Lp = sandy eolian dune over lacustrine plain) See appropriate map (listed in field 21) for label descriptions. 21 GEOLOGY; GSC Map #: The GSC map number of the published GSC surficial geology map used for fields 18, 19, and 20. 22 LANDSLIDE COMMENTS; Estimated age: Age is estimated as accurately as possible. Age may simply predate the earliest photos (i.e. pre-1948) or be bracketed by photos or publications (i.e. 1960-70), or, in rare instances, age is known (i.e. 27/6/90). 23 LANDSLIDE COMMENTS; Active/stable: Activity of landslide at time of most recent airphoto or report. Condition is reported as active (A) or stable (S). 24 LANDSLIDE COMMENTS; Comments: Any extra comments referring to characteristics of the landslide. 25-39 AIRPHOTO INFORMATION: These columns are a listing of airphoto information. Up to 3 different coverages are presented, if available. If more than 3 coverages exist, those flights which best illustrate the slide over time are selected. 25 Flight line #: National Airphoto Library airphoto flight line number 26 Frame #: Individual airphoto number 27 Flight date: Date of photography 28 Elevation: Elevation of flight line, in feet above sea level. 29 Scale: Scale of airphoto 30-39 Repeat fields 25-29 if additional coverage is available. 40 REFERENCE: Reference, if the landslide has been discussed in a publication.