Permafrost by permafrost. Of this area slightly more than half is underlain by continuous permafrost, around 20 percent by discontinuous permafrost, and a little less than 30 percent by sporadic permafrost. Most of this area is found in Siberia, northern Canada, Alaska and Greenland. Beneath the active layer annual temperature swings of permafrost become smaller with depth. The deepest depth of permafrost occurs where geothermal heat maintains a temperature above freezing. Above that bottom limit there may be permafrost, whose temperature doesn't change annually—"isothermal permafrost". Permafrost typically forms in any climate where the mean annual air temperature is less than the
Women in the military by country forces with the creation of the Army Nursing Service in 1899. On the 30th of June 2017, women were found to make up 16.5% of the Australian Defence Force (with 20.6% in the Royal Australian Air Force, 20.4% in the Royal Australian Navy and 13.2% in the Australian Army). However, up until 2016, only 74% of the total number of available roles in the Australian armed forces were available to women. Despite this, using 1998-99 figures, the ADF had the highest percentage of women in its employ in the world. In 1998, Australia became the fourth nation in the world