page_title: Glacier
section_title: Moraines
hierarchical_section_title: Glacier / Glacial geology / Moraines
caption_attribution_description: English: Glacial moraines above Lake Louise, Alberta, Canada.
context_page_description: A glacier is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. Glaciers slowly deform and flow under stresses induced by their weight, creating crevasses, seracs, and other distinguishing features. They also abrade rock and debris from their substrate to create landforms such as cirques and moraines. Glaciers form only on land and are distinct from the much thinner sea ice and lake ice that form on the surface of bodies of water.
  On Earth, 99% of glacial ice is contained within vast ice sheets in the polar regions, but glaciers may be found in mountain ranges on every continent including Oceania's high-latitude oceanic island countries such as New Zealand. Between latitudes 35°N and 35°S, glaciers occur only in the Himalayas, Andes, and a few high mountains in East Africa, Mexico, New Guinea and on Zard Kuh in Iran. With more than 7,000, Pakistan has more glaciers than anywhere except the polar regions. Glaciers cover about 10% of Earth's land surface.
context_section_description: Glacial moraines are formed by the deposition of material from a glacier and are exposed after the glacier has retreated.  They usually appear as linear mounds of till, a non-sorted mixture of rock, gravel, and boulders within a matrix of fine powdery material. Terminal or end moraines are formed at the foot or terminal end of a glacier. Lateral moraines are formed on the sides of the glacier. Medial moraines are formed when two different glaciers merge and the lateral moraines of each coalesce to form a moraine in the middle of the combined glacier. Less apparent are ground moraines, also called glacial drift, which often blankets the surface underneath the glacier downslope from the equilibrium line. The term moraine is of French origin.  It was coined by peasants to describe alluvial embankments and rims found near the margins of glaciers in the French Alps. In modern geology, the term is used more broadly and is applied to a series of formations, all of which are composed of till. Moraines can also create moraine-dammed lakes.
caption: Glacial moraines above Lake Louise, Alberta, Canada
exif: {"Image Make": "NIKON", "Image Model": "COOLPIX P90", "Image Orientation": "Horizontal (normal)", "Image XResolution": "300", "Image YResolution": "300", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "Adobe Photoshop CS Macintosh", "Image DateTime": "2009:08:15 09:40:37", "Image YCbCrPositioning": "Centered", "Image ExifOffset": "220", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "962", "Thumbnail JPEGInterchangeFormatLength": "5910", "EXIF ExposureTime": "365497/100000000", "EXIF FNumber": "28/5", "EXIF ExposureProgram": "Program Normal", "EXIF ISOSpeedRatings": "64", "EXIF ExifVersion": "0220", "EXIF DateTimeOriginal": "2009:08:07 13:46:05", "EXIF DateTimeDigitized": "2009:08:07 13:46:05", "EXIF ComponentsConfiguration": "YCbCr", "EXIF ExposureBiasValue": "0", "EXIF MaxApertureValue": "3", "EXIF MeteringMode": "Pattern", "EXIF LightSource": "Unknown", "EXIF Flash": "Flash did not fire, compulsory flash mode", "EXIF FocalLength": "23/5", "EXIF FlashPixVersion": "0100", "EXIF ColorSpace": "sRGB", "EXIF ExifImageWidth": "4000", "EXIF ExifImageLength": "2874", "Interoperability InteroperabilityIndex": "R98", "Interoperability InteroperabilityVersion": "[48, 49, 48, 48]", "EXIF InteroperabilityOffset": "836", "EXIF FileSource": "Digital Camera", "EXIF SceneType": "Directly Photographed", "EXIF CustomRendered": "Normal", "EXIF ExposureMode": "Auto Exposure", "EXIF WhiteBalance": "Auto", "EXIF DigitalZoomRatio": "0", "EXIF FocalLengthIn35mmFilm": "26", "EXIF SceneCaptureType": "Standard", "EXIF GainControl": "None", "EXIF Contrast": "Normal", "EXIF Saturation": "Normal", "EXIF Sharpness": "Normal", "EXIF SubjectDistanceRange": "0"}