\u00a0<\/p>\n
[\/et_pb_text][et_pb_text _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d header_2_text_color=\u201d#334556\u2033 header_2_font_size=\u201d33px\u201d header_2_line_height=\u201d1.4em\u201d custom_padding=\u201d||40px||false|false\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d]<\/p>\n
It is an object of fascination for explorers, shelters unexpected living creatures and regulates our climate. But what do we really know about the icy skin<\/a> covering our polar oceans<\/strong>? Glaciologist and PONANT EXPLORATIONS naturalist guide Daphn\u00e9 Buiron shares the secrets of the pack ice<\/strong> with us and introduces us to a complex world that is bursting with far more life than we might imagine.<\/p>\n [\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row custom_padding_last_edited=\u201don|phone\u201d admin_label=\u201dMEA \u2013 classic\u201d _builder_version=\u201d4.16\u2033 _module_preset=\u201ddefault\u201d background_color=\u201d#f7f7f7\u2033 width_tablet=\u201d\u201d width_phone=\u201d100%\u201d width_last_edited=\u201don|phone\u201d max_width=\u201d1000px\u201d custom_margin=\u201d||50px||false|false\u201d custom_padding=\u201d|50px|50px|50px|false|true\u201d custom_padding_tablet=\u201d\u201d custom_padding_phone=\u201d|40px||40px|false|true\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d][et_pb_column type=\u201d4_4\u2033 _builder_version=\u201d4.16\u2033 _module_preset=\u201ddefault\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d][et_pb_text _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d header_2_font=\u201d|300|on||||||\u201d header_2_text_align=\u201dcenter\u201d background_enable_color=\u201doff\u201d custom_padding=\u201d|20px||20px|true|true\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d]<\/p>\n [\/et_pb_text][et_pb_divider show_divider=\u201doff\u201d _builder_version=\u201d4.16\u2033 _module_preset=\u201ddefault\u201d width=\u201d15%\u201d width_tablet=\u201d150px\u201d width_phone=\u201d150px\u201d width_last_edited=\u201don|phone\u201d module_alignment=\u201dcenter\u201d custom_margin=\u201d||40px||false|false\u201d custom_padding=\u201d||||false|false\u201d border_width_bottom=\u201d4px\u201d border_color_bottom=\u201d#26afc2\u2033 global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d][\/et_pb_divider][et_pb_text _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d]<\/p>\n [\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row _builder_version=\u201d4.16\u2033 _module_preset=\u201ddefault\u201d max_width=\u201d900px\u201d custom_padding=\u201d0px||0px||true|false\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d][et_pb_column type=\u201d4_4\u2033 _builder_version=\u201d4.16\u2033 _module_preset=\u201ddefault\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d][et_pb_text _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d header_2_font=\u201d|600|||||||\u201d header_2_font_size=\u201d23px\u201d header_2_line_height=\u201d1.2em\u201d custom_padding=\u201d0px||0px||false|false\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d]<\/p>\n [\/et_pb_text][et_pb_text _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d header_2_font=\u201d|300|||||||\u201d header_2_text_color=\u201d#334556\u2033 header_2_font_size=\u201d38px\u201d custom_padding=\u201d14px||21px||false|false\u201d hover_enabled=\u201d0\u2033 global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d sticky_enabled=\u201d0\u2033]<\/p>\n Pack ice<\/strong> has an official name which explains precisely what it is: \u201csea ice<\/strong>\u201d. It is literally frozen sections of the ocean which appear in winter as the cold takes hold. Saltwater doesn\u2019t freeze at 0\u00b0C (32\u00b0F); temperatures have to get as low as -1.8\u00b0C<\/strong> (28\u00b0F). When they do, ice crystals form on the surface and gradually start to fuse together. Small crystals<\/strong> emerge first, which get bigger until they thicken to form a solid layer<\/strong>.<\/p>\n [\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row _builder_version=\u201d4.16\u2033 _module_preset=\u201ddefault\u201d max_width=\u201d900px\u201d custom_padding=\u201d0px||0px||true|false\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d][et_pb_column type=\u201d4_4\u2033 _builder_version=\u201d4.16\u2033 _module_preset=\u201ddefault\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d][et_pb_text _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d header_2_font=\u201d|600|||||||\u201d header_2_font_size=\u201d23px\u201d header_2_line_height=\u201d1.2em\u201d custom_padding=\u201d0px||0px||false|false\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d]<\/p>\n [\/et_pb_text][et_pb_text _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d header_2_font=\u201d|300|||||||\u201d header_2_text_color=\u201d#334556\u2033 header_2_font_size=\u201d38px\u201d custom_padding=\u201d14px||21px||false|false\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d]<\/p>\n Pack ice formation is a seasonal phenomenon<\/strong>. In spring, as the sun and warm air return, the pack ice starts to break up, melt and finally disappear until the following winter. This is why it\u2019s known as annual pack ice<\/strong>. But in some sheltered areas of the High Arctic<\/strong>, such as north-east Greenland<\/a><\/u>, sometimes the pack ice survives the summer and lasts for one or more years. This particularly solid perennial pack ice<\/strong> can be as thick as six to seven metres<\/strong>, with pressure ridges included. It records climate history, making it particularly important to protect.<\/p>\n [\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row _builder_version=\u201d4.16\u2033 _module_preset=\u201ddefault\u201d max_width=\u201d900px\u201d custom_padding=\u201d0px||0px||true|false\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d][et_pb_column type=\u201d4_4\u2033 _builder_version=\u201d4.16\u2033 _module_preset=\u201ddefault\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d][et_pb_text _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d header_2_font=\u201d|600|||||||\u201d header_2_font_size=\u201d23px\u201d header_2_line_height=\u201d1.2em\u201d custom_padding=\u201d0px||0px||false|false\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d]<\/p>\n [\/et_pb_text][et_pb_text _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d header_2_font=\u201d|300|||||||\u201d header_2_text_color=\u201d#334556\u2033 header_2_font_size=\u201d38px\u201d custom_padding=\u201d14px||21px||false|false\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d]<\/p>\n When pack ice forms, the salt in seawater is mainly ejected via tiny fissures called brine drainage channels<\/strong>. As a result, pack ice is a lot less salty than its surrounding oceans.<\/p>\n [\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row _builder_version=\u201d4.16\u2033 _module_preset=\u201ddefault\u201d max_width=\u201d900px\u201d custom_padding=\u201d0px||0px||true|false\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d][et_pb_column type=\u201d4_4\u2033 _builder_version=\u201d4.16\u2033 _module_preset=\u201ddefault\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d][et_pb_text _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d header_2_font=\u201d|600|||||||\u201d header_2_font_size=\u201d23px\u201d header_2_line_height=\u201d1.2em\u201d custom_padding=\u201d0px||8px||false|false\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d]<\/p>\n [\/et_pb_text][et_pb_image src=\u201dhttps:\/\/escales.ponant.com\/wp-content\/uploads\/2026\/04\/Low-Resolution-110_0O5A7714_reperage_groenland_illulisat_baie_disko_icebergs_kullorsuaq_\u00a9ponant_julien_fabro-1.jpg\u201d alt=\u201dIcebergs stuck in the pack ice in Disko Bay, Greenland\u201d title_text=\u201dsecrets-pack-ice\u201d _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d custom_padding=\u201d||12px|||\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d][\/et_pb_image][et_pb_text _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d theme_builder_area=\u201dpost_content\u201d hover_enabled=\u201d0\u2033 sticky_enabled=\u201d0\u2033]<\/p>\n Icebergs stuck in the pack ice in Disko Bay, Greenland<\/span><\/span>\u00a0<\/span><\/p>\n [\/et_pb_text][et_pb_text _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d header_2_font=\u201d|300|||||||\u201d header_2_text_color=\u201d#334556\u2033 header_2_font_size=\u201d38px\u201d custom_padding=\u201d19px||21px||false|false\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d]<\/p>\n While icebergs often get trapped in pack ice in winter, they aren\u2019t made of seawater. Icebergs are formed on land, in that they are actually pieces of glacier<\/strong> (compacted snow turned into ice) which have come away and fallen into the sea. As such, icebergs are made of freshwater<\/strong>. Pack ice, on the other hand, is made in the sea, as it\u2019s frozen ocean water<\/strong>. It generally starts to form in sheltered areas such as bays and fjords<\/strong> by attaching itself to the coastline before extending out to sea.<\/p>\n [\/et_pb_text][et_pb_text _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d header_2_font=\u201d|300|||||||\u201d header_2_text_color=\u201d#334556\u2033 header_2_font_size=\u201d38px\u201d custom_padding=\u201d19px||21px||false|false\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d]<\/p>\n Visually, icebergs and pack ice are opposites. The latter is a thin layer of no more than a few metres<\/strong>, while an iceberg is a very hard, very much taller and thicker mountain of ice which might rise tens of metres<\/strong> above the surface and several hundreds of metres below.<\/p>\n [\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row _builder_version=\u201d4.16\u2033 _module_preset=\u201ddefault\u201d max_width=\u201d900px\u201d custom_padding=\u201d0px||0px||true|false\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d][et_pb_column type=\u201d4_4\u2033 _builder_version=\u201d4.16\u2033 _module_preset=\u201ddefault\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d][et_pb_text _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d header_2_font=\u201d|600|||||||\u201d header_2_font_size=\u201d23px\u201d header_2_line_height=\u201d1.2em\u201d custom_padding=\u201d0px||0px||false|false\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d]<\/p>\n [\/et_pb_text][et_pb_text _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d header_2_font=\u201d|300|||||||\u201d header_2_text_color=\u201d#334556\u2033 header_2_font_size=\u201d38px\u201d custom_padding=\u201d19px||21px||false|false\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d]<\/p>\n The Arctic is surrounded by land and the pack ice is more centralised, thicker (averaging two to three metres, compared with one to two in Antarctica) and permanent at the North Pole. It grows in winter, spreading down into lower latitudes<\/strong> as far as northern Greenland, Spitsbergen and Canada\u2019s Arctic islands.<\/p>\n [\/et_pb_text][et_pb_text _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d header_2_font=\u201d|300|||||||\u201d header_2_text_color=\u201d#334556\u2033 header_2_font_size=\u201d38px\u201d custom_padding=\u201d19px||21px||false|false\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d]<\/p>\n The opposite is true in the Antarctic, which is an immense continent ringed by an ocean. The pack ice forms around it<\/strong>, but not as far because it quickly reaches warmer latitudes. In both cases, we can see it pulse<\/strong> with the seasons, as the ice stretches out during polar night<\/strong>, thickening from underneath, and shrinks in summer. These dynamic environments never stop moving.<\/p>\n [\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row _builder_version=\u201d4.16\u2033 _module_preset=\u201ddefault\u201d max_width=\u201d900px\u201d custom_padding=\u201d0px||0px||true|false\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d][et_pb_column type=\u201d4_4\u2033 _builder_version=\u201d4.16\u2033 _module_preset=\u201ddefault\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d][et_pb_text _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d header_2_font=\u201d|600|||||||\u201d header_2_font_size=\u201d23px\u201d header_2_line_height=\u201d1.2em\u201d custom_padding=\u201d0px||18px||false|false\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d]<\/p>\n [\/et_pb_text][et_pb_image src=\u201dhttps:\/\/escales.ponant.com\/wp-content\/uploads\/2026\/04\/Low-Resolution-29_CC260924_North-Pole_Ice-Abstract\u00a9PONANT-Benjamin-Hardman-1.jpg\u201d alt=\u201dPancake ice in the Arctic\u201d title_text=\u201dsecrets-pack-ice\u201d _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d custom_padding=\u201d||11px|||\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d][\/et_pb_image][et_pb_text _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d theme_builder_area=\u201dpost_content\u201d hover_enabled=\u201d0\u2033 sticky_enabled=\u201d0\u2033]<\/p>\n Pancake ice in the Arctic<\/span><\/span><\/p>\n [\/et_pb_text][et_pb_text _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d header_2_font=\u201d|300|||||||\u201d header_2_text_color=\u201d#334556\u2033 header_2_font_size=\u201d38px\u201d custom_padding=\u201d13px||29px||false|false\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d]<\/p>\n This landscape is always changing<\/strong> and the ice\u2019s shape tells us how it formed. If the sea is rough when it freezes, little rings of ice crystals<\/strong> group together and collide with one another, so much so that their sharp edges might be worn smooth and curl upwards to make pancake ice<\/strong> (whose pieces will ultimately fuse together).<\/p>\n [\/et_pb_text][et_pb_text _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d header_2_font=\u201d|300|||||||\u201d header_2_text_color=\u201d#334556\u2033 header_2_font_size=\u201d38px\u201d custom_padding=\u201d13px||29px||false|false\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d]<\/p>\n Alternatively, in sheltered spots, the surface will set all of a sudden, forming an immense smooth sheet<\/strong> which looks dark, elastic and something like a window. This is called nilas ice<\/strong> and it is very thin at just two or three centimetres. It undulates with the waves without ever breaking and it is impossible to walk on, but it is fascinating to see nonetheless.<\/p>\n [\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row _builder_version=\u201d4.16\u2033 _module_preset=\u201ddefault\u201d max_width=\u201d900px\u201d custom_padding=\u201d0px||0px||true|false\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d][et_pb_column type=\u201d4_4\u2033 _builder_version=\u201d4.16\u2033 _module_preset=\u201ddefault\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d][et_pb_text _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d header_2_font=\u201d|600|||||||\u201d header_2_font_size=\u201d23px\u201d header_2_line_height=\u201d1.2em\u201d custom_padding=\u201d0px||18px||false|false\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d]<\/p>\n [\/et_pb_text][et_pb_image src=\u201dhttps:\/\/escales.ponant.com\/wp-content\/uploads\/2026\/04\/Low-Resolution-34_Paysage-du-bateau_banquise_CDT-Charcot\u00a9StudioPONANT-Olivier-Blaud-1.jpg\u201d alt=\u201dA pressure ridge on the pack ice in Greenland\u201d title_text=\u201dsecrets-pack-ice\u201d _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d custom_padding=\u201d||9px|||\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d][\/et_pb_image][et_pb_text _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d theme_builder_area=\u201dpost_content\u201d hover_enabled=\u201d0\u2033 sticky_enabled=\u201d0\u2033]<\/p>\n A pressure ridge on the pack ice in Greenland<\/span><\/span>\u00a0<\/span><\/p>\n [\/et_pb_text][et_pb_text _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d header_2_font=\u201d|300|||||||\u201d header_2_text_color=\u201d#334556\u2033 header_2_font_size=\u201d38px\u201d custom_padding=\u201d13px||29px||false|false\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d]<\/p>\n With the ocean moving beneath them, the pieces of ice<\/strong> are fused together to a greater or lesser degree, but they are always doing something. When two pieces collide, they form \u201cpressure ridges<\/strong>\u201d, or great blocks of ice that can rise several metres into the air<\/strong>. Their jagged surface makes the terrain extremely treacherous.<\/p>\n [\/et_pb_text][et_pb_text _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d header_2_font=\u201d|300|||||||\u201d header_2_text_color=\u201d#334556\u2033 header_2_font_size=\u201d38px\u201d custom_padding=\u201d13px||29px||false|false\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d]<\/p>\n Conversely, when pieces move apart<\/strong>, dark channels of water open up. These fissures can be hidden under the snow, which is why guides always test the ice during expeditions to mark out a completely safe route<\/strong>.<\/p>\n [\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row column_structure=\u201d2_5,3_5\u2033 admin_label=\u201dMEA \u2013 decalage\u201d _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d max_width=\u201d900px\u201d custom_padding=\u201d50px||50px||true|false\u201d locked=\u201doff\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d][et_pb_column type=\u201d2_5\u2033 _builder_version=\u201d4.16\u2033 _module_preset=\u201ddefault\u201d background_enable_color=\u201doff\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d][et_pb_text _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d header_2_font=\u201d|300|on||||||\u201d header_2_text_align=\u201dleft\u201d header_2_text_color=\u201d#ffffff\u201d header_2_line_height=\u201d1.4em\u201d background_color=\u201d#307f90\u2033 background_enable_image=\u201doff\u201d custom_margin=\u201d|-30%|||false|false\u201d custom_margin_tablet=\u201d|0%|||false|false\u201d custom_margin_phone=\u201d\u201d custom_margin_last_edited=\u201don|tablet\u201d custom_padding=\u201d30px|75%|30px|20px|true|false\u201d custom_padding_tablet=\u201d|20px|||true|false\u201d custom_padding_phone=\u201d\u201d custom_padding_last_edited=\u201don|tablet\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d]<\/p>\n [\/et_pb_text][\/et_pb_column][et_pb_column type=\u201d3_5\u2033 _builder_version=\u201d4.16\u2033 _module_preset=\u201ddefault\u201d background_enable_color=\u201doff\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d][et_pb_text _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d background_color=\u201d#f7f7f7\u2033 custom_margin=\u201d50px|||-25%|false|false\u201d custom_margin_tablet=\u201d0px|||0%|false|false\u201d custom_margin_phone=\u201d\u201d custom_margin_last_edited=\u201don|desktop\u201d custom_padding=\u201d40px|40px|40px|40px|true|true\u201d custom_padding_tablet=\u201d|20px||20px|true|true\u201d custom_padding_phone=\u201d\u201d custom_padding_last_edited=\u201don|tablet\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d]<\/p>\n To test how solid the ice is, guides use a traditional Inuit tool known as a tuuq<\/strong>. These long sticks have a metal point at the end. When they strike the ice, the sound it makes and the way it withstands impact<\/strong> tells us how thick it is. Thirty centimetres<\/strong> of consistent ice is considered solid enough to hold a group of people, and lorries can drive across pieces measuring 60 centimetres or more. In late winter, annual pack ice might get as thick as two metres<\/strong>.<\/p>\n [\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row _builder_version=\u201d4.16\u2033 _module_preset=\u201ddefault\u201d max_width=\u201d900px\u201d custom_padding=\u201d0px||0px||true|false\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d][et_pb_column type=\u201d4_4\u2033 _builder_version=\u201d4.16\u2033 _module_preset=\u201ddefault\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d][et_pb_text _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d header_2_font=\u201d|600|||||||\u201d header_2_font_size=\u201d23px\u201d header_2_line_height=\u201d1.2em\u201d custom_padding=\u201d0px||18px||false|false\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d]<\/p>\n [\/et_pb_text][et_pb_image src=\u201dhttps:\/\/escales.ponant.com\/wp-content\/uploads\/2026\/04\/Low-Resolution-IMGL9139_CC140525_commandant_charcot_groenland_Ammassalik_glace_sunset_banquise\u00a9ponant_julien_fabro-1.jpg\u201d alt=\u201dDrift ice off Greenland\u201d title_text=\u201dsecrets-pack-ice\u201d _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d custom_padding=\u201d||13px|||\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d][\/et_pb_image][et_pb_text _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d theme_builder_area=\u201dpost_content\u201d hover_enabled=\u201d0\u2033 sticky_enabled=\u201d0\u2033]<\/p>\n Drift ice off Greenland<\/span><\/span><\/p>\n [\/et_pb_text][et_pb_text _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d header_2_font=\u201d|300|||||||\u201d header_2_text_color=\u201d#334556\u2033 header_2_font_size=\u201d38px\u201d custom_padding=\u201d13px||29px||false|false\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d]<\/p>\n It all comes down to movement. Fast ice<\/strong> stays at the shore, stuck to rocks or islands. It\u2019s stable and safe for wildlife in springtime<\/strong>. In fact, it\u2019s here that seals birth their young and bears hunt. It\u2019s also used by Inuit to get around on dog sleds and set up hunting camps.<\/p>\n [\/et_pb_text][et_pb_text _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d header_2_font=\u201d|300|||||||\u201d header_2_text_color=\u201d#334556\u2033 header_2_font_size=\u201d38px\u201d custom_padding=\u201d13px||29px||false|false\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d]<\/p>\n However, once the ice comes away <\/strong>in the wind and starts floating off to sea, it becomes drift ice. It moves with the water currents, forming pieces of varying size. At this point, the ice has become unstable. If the pieces are huge, the visual difference between fast and drift ice<\/strong> is subtle, but when the latter starts to break up, the landscape is a lot more fractured.<\/p>\n [\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row _builder_version=\u201d4.16\u2033 _module_preset=\u201ddefault\u201d max_width=\u201d900px\u201d custom_padding=\u201d0px||0px||true|false\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d][et_pb_column type=\u201d4_4\u2033 _builder_version=\u201d4.16\u2033 _module_preset=\u201ddefault\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d][et_pb_text _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d header_2_font=\u201d|600|||||||\u201d header_2_font_size=\u201d23px\u201d header_2_line_height=\u201d1.2em\u201d custom_padding=\u201d0px||18px||false|false\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d]<\/p>\n [\/et_pb_text][et_pb_image src=\u201dhttps:\/\/escales.ponant.com\/wp-content\/uploads\/2026\/04\/Low-Resolution-4_Antarctica_Banquise_Fine-whale\u00a9StudioPONANT-Nath-Michel-1.jpg\u201d alt=\u201dA whale feeding in the water around the pack ice in Antarctica\u201d title_text=\u201dsecrets-pack-ice\u201d _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d custom_padding=\u201d||20px|||\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d][\/et_pb_image][et_pb_text _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d theme_builder_area=\u201dpost_content\u201d hover_enabled=\u201d0\u2033 sticky_enabled=\u201d0\u2033]<\/p>\n A whale feeding in the water around the pack ice in Antarctica<\/span><\/span>\u00a0<\/span><\/p>\n [\/et_pb_text][et_pb_text _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d header_2_font=\u201d|300|||||||\u201d header_2_text_color=\u201d#334556\u2033 header_2_font_size=\u201d38px\u201d custom_padding=\u201d13px||9px||false|false\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d]<\/p>\n Polynyas<\/strong> are hard to spot from the bridge of a ship because they\u2019re so huge, but they are very visible via satellite<\/strong>.\u00a0 They are a vast zone of water in the middle of the pack ice<\/strong> which never freezes, even in extremely cold temperatures<\/strong>, because of constant winds or water currents. Paradoxically, this is where most sea ice is \u201cmade\u201d, because it\u2019s always forming then being pushed out by the wind.<\/p>\n [\/et_pb_text][et_pb_text _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d header_2_font=\u201d|300|||||||\u201d header_2_text_color=\u201d#334556\u2033 header_2_font_size=\u201d38px\u201d custom_padding=\u201d13px||29px||false|false\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d]<\/p>\n Polynyas are vital for the ecosystem<\/strong>, in that the unfrozen water offers crucial breathing space. Sea mammals<\/strong> such as whales, narwhals and seals can come take some air and find food in the depths of winter without ice getting in the way.<\/p>\n [\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row _builder_version=\u201d4.16\u2033 _module_preset=\u201ddefault\u201d max_width=\u201d900px\u201d custom_padding=\u201d0px||0px||true|false\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d][et_pb_column type=\u201d4_4\u2033 _builder_version=\u201d4.16\u2033 _module_preset=\u201ddefault\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d][et_pb_text _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d header_2_font=\u201d|600|||||||\u201d header_2_font_size=\u201d23px\u201d header_2_line_height=\u201d1.2em\u201d custom_padding=\u201d0px||0px||false|false\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d]<\/p>\n [\/et_pb_text][et_pb_text _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d header_2_font=\u201d|300|||||||\u201d header_2_text_color=\u201d#334556\u2033 header_2_font_size=\u201d38px\u201d custom_padding=\u201d13px||29px||false|false\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d]<\/p>\n The pack ice isn\u2019t sterile<\/strong> and it has a crucial role to play as the basis for the entire polar food chain.<\/strong>\u00a0 In winter, during polar night, microalgae and bacteria<\/strong> shelter in cracks in the ice. In spring, sunlight shines on the now-thinner pack ice and the bloom takes place. Phytoplankton bursts into life<\/strong> below surface to form vast underwater meadows<\/strong>. These are the basis for the entire polar food chain. The algae nourish the krill, which nourish the fish, birds, penguins, seals and whales<\/strong>. Without the pack ice to protect the phytoplankton, the entire ecosystem would collapse.<\/p>\n [\/et_pb_text][\/et_pb_column][\/et_pb_row][et_pb_row _builder_version=\u201d4.16\u2033 _module_preset=\u201ddefault\u201d max_width=\u201d900px\u201d custom_padding=\u201d0px||0px||true|false\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d][et_pb_column type=\u201d4_4\u2033 _builder_version=\u201d4.16\u2033 _module_preset=\u201ddefault\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d][et_pb_text _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d header_2_font=\u201d|600|||||||\u201d header_2_font_size=\u201d23px\u201d header_2_line_height=\u201d1.2em\u201d custom_padding=\u201d0px||18px||false|false\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d]<\/p>\n [\/et_pb_text][et_pb_image src=\u201dhttps:\/\/escales.ponant.com\/wp-content\/uploads\/2026\/04\/Low-Resolution-No-2079_CC050425_navigation-ours-polaire\u00a9StudioPONANT_MorganeMonneret-1.jpg\u201d alt=\u201dA polar bear hunting on the pack ice in Greenland\u201d title_text=\u201dsecrets-pack-ice\u201d _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d custom_padding=\u201d||20px|||\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d][\/et_pb_image][et_pb_text _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d theme_builder_area=\u201dpost_content\u201d hover_enabled=\u201d0\u2033 sticky_enabled=\u201d0\u2033]<\/p>\n A polar bear hunting on the pack ice in Greenland\u00a0<\/span><\/span><\/p>\n [\/et_pb_text][et_pb_text _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d header_2_font=\u201d|300|||||||\u201d header_2_text_color=\u201d#334556\u2033 header_2_font_size=\u201d38px\u201d custom_padding=\u201d13px||29px||false|false\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d]<\/p>\n Pack ice is an essential environment for polar wildlife<\/strong>. Its first purpose is reproduction<\/strong>. Seals birth their young on the fast ice in spring, as their babies can\u2019t swim. The pack ice also provides seals with a dry place to sleep<\/strong> and shelter from ocean predators such as orcas after long periods of a week or more out fishing.<\/p>\n [\/et_pb_text][et_pb_text _builder_version=\u201d4.27.6\u2033 _module_preset=\u201ddefault\u201d header_2_font=\u201d|300|||||||\u201d header_2_text_color=\u201d#334556\u2033 header_2_font_size=\u201d38px\u201d custom_padding=\u201d13px||29px||false|false\u201d global_colors_info=\u201d{}\u201d theme_builder_area=\u201dpost_content\u201d]<\/p>\nKey information:<\/h2>\n
\n
What exactly is \u201cpack ice\u201d?<\/h2>\n
Can you see pack ice all year round?<\/h2>\n
Is pack ice salty?<\/h2>\n
What\u2019s the difference between an iceberg and pack ice?<\/h2>\n
How does pack ice spread out in the Arctic, as compared with the Antarctic?<\/h2>\n
Pack ice sometimes takes on extraordinary shapes\u2026<\/h2>\n
Why isn\u2019t the pack ice smooth?<\/h2>\n
![\"A](\"https:\/\/escales.ponant.com\/wp-content\/uploads\/2026\/04\/Low-Resolution-0O5A9934_CC140525_commandant_charcot_groenland_Ammassalik_guide%C2%A9ponant_julien_fabro-1.jpg\")
<\/h2>\nThe tuuq: an essential tool in a guide\u2019s kit<\/h2>\n
Ice can be described as \u201cfast\u201d or \u201cdrift\u201d. What\u2019s the difference?<\/h2>\n
A strange phenomenon called a polynya sometimes descends on these white landscapes. Can you tell us more about this?<\/h2>\n
Another life force is concealed under the ice\u2019s surface. What is phytoplankton bloom?<\/h2>\n
How does the wildlife use the pack ice physically, in addition to finding food?<\/h2>\n
![\"A](\"https:\/\/escales.ponant.com\/wp-content\/uploads\/2026\/04\/Low-Resolution-153_IMGL4154_reperage_groenland_kullorsuaq_inuits_chiens_traineau_glace_kullorsuaq_%C2%A9ponant_julien_fa-1.jpg\")
<\/h2>\n![\"\"](\"https:\/\/escales.ponant.com\/wp-content\/uploads\/2026\/04\/photo-Daphne-Buiron-350x240.jpg\")
<\/h2>\n