What is an iceberg? Why are they blue or green? An iceberg is a large floating block of freshwater ice that has broken off the edge of a glacier and been carried out to sea; about 90% of its mass lies under the water. The bluish streaks of clear, bubble free ice often seen in icebergs results from the refreezing of melt water which fills crevasses formed in the glacier as it creeps over land. The ice is blue because of the natural light scattering characteristics of pure ice. Occasionally airborne dust or dirt eroded from land ends up on the glacier surface eventually forming a noticeably darkened brown or black layer (in any orientation) within the ice of a floating iceberg. What type of information can scientists obtain from polar ice? Polar Regions and some alpine areas are sufficiently cold that snowfall accumulates from year to year, building up as glaciers. As snow at the surface gets buried with time it gets compressed to form solid ice and this ice carries with it information about the climate when the snow originally fell. By drilling down into a glacier and recovering this old ice, the information can be used to help understand past climate. The information obtained from ice cores can be divided into three types. The first of these types of information comes from the solid and dissolved impurities in the snow. Usually snow that falls in those places is almost pure water, but it still contains traces of dust, and pollutants from human activities. This information can be used to detect major environmental changes in the circulation of the atmosphere. The second type of information obtained from ice cores comes from bubbles in the glacier ice. These bubbles are formed as snow becomes compressed and the air between the flakes gets trapped. The third type of information obtained from ice cores comes from the frozen water itself. In the oceans, one in about every 500 oxygen atoms is the heavy isotope, while one in about 70 hydrogen atoms is heavy. However as the water evaporates and is transported to polar regions, the mix of the heavy isotopes changes. These changes are mostly influenced by temperature and it turns out that by measuring water isotopes in ice cores researchers can infer temperatures when the snow originally fell. In the past 30 years, many ice cores have been drilled to study past climate.
In this essay, the author
- Explains that an iceberg is a floating block of freshwater water that has broken off the edge of the glacier and been carried out to sea; 90% of its mass lies under the water.
- Explains that a fathom is an unit of length equal to 6 feet (1.83 meters), used principally in the measurement and specification of marine depths.
- Explains the three types of information obtained from ice cores: solid and dissolved impurities, bubbles, and frozen water.
- Explains that bathymetry is the measurement of the depths of oceans, seas or other large bodies of water, typically using narrow swath acoustic systems.
- Explains the odor of ocean sediments, which is produced by bacteria below the surface of the marsh muds.
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- The Ablation Of The Greenland Ice Sheet Hydrologyexplanatory essayThe mass of the Greenland Ice Sheet is gained from snowfall and loss by melt and iceberg calving. Surface mass balance (SMB) refers to mass exchanges at the surface of the ice sheet. Accumulation of the SMB occurs through snowfall and also the refreezing of melt water. This upper region of mass surplus is known as the accumulation zone. Ablation of the SRB occurs when ice on the surface melts or is sublimated. This lower region of mass deficit is the ablation zone. The boundary between these two zones is defined as the equilibrium line.
In this essay, the author
- Explains that melting has been observed by automatic weather stations on the greenland ice sheet, as well as through remote sensing. the largest amount of melting occurred in the western region of the ice sheet rather than the eastern portion.
- Explains that the warming rate in the artic regions has been greater than other parts of the world. summit, greenland, is six times larger than the global average.
- Explains that the mass of the greenland ice sheet is gained from snowfall and loss by melt and iceberg calving. surface mass balance (smb) refers to mass exchanges at the surface.
- Explains that the accumulation zone can be categorized into three typical glacier facies with varying hydrologic processes.
- Concludes that the expansion of bare ice area and associated albedo changes farther into the greenland ice sheet interior can play a large role in meltwater production.
- Explains that mass losses in the greenland ice sheet have increased over the years due to dynamic changes to outlet glacier velocity, calving rates, and ice thickness.
- Explains that meltwater runoff is estimated to account for over half of the greenland ice sheet mass loss. there are complex pathways that transport it to the ice edge and ocean.
- Explains the increase in runoff from regional drainage basins over the last half-century, which has been mostly offset by increased precipitation according to mass balance estimates.
- Explains that changes in meltwater input to glacial environments are widely shown to be related to ice dynamics.
- Explains that meltwater produced on the ice surface is transported from its origin in a variety of ways. it can move through supraglacial stream networks and lakes.
- Explains that surface meltwater percolates through snow and firn and will later refreeze at a cooler depth. low lying areas will allow the melt water to accumulate and form slush zones and supraglacial lakes.
- Explains that over impermeable ice or dense firn, meltwater can pool up in depressions and establish supraglacial lakes. these lakes can appear over multiple years, and reform in the same area.
- Explains that lake location and size is driven by multiple factors such as the time of the season, elevation, and topography.
- Argues that monitoring lake development and drainage will become essential due to the changing climate, to assess supraglacial lakes importance in meltwater storage and its transport.
- Explains that modeling lake depth and volume is needed to assess the potential storage or influx of meltwater into the ice sheet through rapid drainage.
- Explains that supraglacial streams are different from terrestials streams because the lack of available sediment, rapid form adjustment, and thermal and frictional melting of a channel add to its discharge.
- Explains that supraglacial streams can form annual, each year, or perennial, forming in same channel for multiple years. perennial streams have a width between 1-30 meters.
- Explains that steam formation is initiated when down cutting by surface channels exceeds surface ablations rates. temperature difference between the ice and water, meltwater discharge, and slope of the channel drive channel incisions.
- Explains that crevasses and moulins are key to ice sheet hydrology because they connect the supraglacial and englacial environments together.
- Explains that moulins provide rapid drainage of large amounts of surface meltwater into englacial and subgalcial systems.
- Explains the theory of channelized englacial flow and how different drainage systems can form including fasts, large tunnels or slow, distributed networks of linked cavities.
- Explains that channels in the subglacial environment are affected by a debris layer on the bedrock. a large influx of meltwater can affect ice sheet dynamics.
2127 wordsRead More - Opposing Views of Glacial Age and History on Mt. Kilimanjaroanalytical essay...this information in a concise and understandable manner which can be used by resource managers and policy makers will be the challenge of scientists. The studies presented here illustrate the uncertainties that may arise when analyzing ice core data and the importance in adequately interpreting and analyzing information obtained from glacial deposits.
In this essay, the author
- Explains that the issue of climate change is becoming increasingly important worldwide, and scientists are looking into the climate history of the past to interpret what this planet may experience in the future.
- Explains how the first ice core-based climate history for africa was reconstructed by thompson et al.
- Explains the techniques used by thompson et al. in the reconstruction included aerial photographs, automatic weather stations, oxygen isotope (o18) and chemical analysis of pertinent elements, and historical information.
- Summarizes thompson et al.'s paper entitled "kilimanjaro ice core records: evidence of holocene climate change in tropical africa".
- Analyzes how the paper attempted to illustrate the effects of climate change while stressing the importance of information taken from ice core data.
- Analyzes kaiser et al's independent study entitled "is the decline on kilimanjaro unprecedented in the holocene?" and explains kaiser and his collogues present three different lines of evidence to support their claim.
- Analyzes the counter argument presented by kaiser et al., which attempted to persuade the audience to question the relevance of work done by thompson and stressed the importance of care when interpreting ice core data.
- Explains that s of both papers agree that mount kilimanjaro's ice fields are declining due to climate conditions. the disagreement between the two studies comes in analyzing the data obtained from
- Analyzes how thompson et al. presented their information in a highly technical manner that may be hard for someone without background in earth science or paleoclimatology to follow.
- Analyzes how kaiser et al.'s paper was organized with topic headings and gave a clear indication of what they were going to talk about.
- Explains that the need to evaluate the impacts of climate change on humans and ecosystems worldwide is important. the studies presented illustrate the uncertainties that may arise when analyzing ice core data.
- Explains that the decline of ice on kilimanjaro is unprecedented in the holocene.
1078 wordsRead More - Greenland Warmingexplanatory essayThe ice sheet extends from about 60° to 83°N over a distance of 2,400 km in the North Atlantic Ocean. The ice sheet covers 1.71 million km2 , or roughly 80% of the surface of Greenland. It consists of a northern dome and a southern dome, with maximum elevations of 3,230 m and 2,850 m, respectively, linked by a long saddle with elevations around 2,500 m. Its total volume is about 2.85 million km3, which, if it were to melt entirely, would raise global sea level by about 7.2 m. The ice sheet has an average thickness of 1,670 m and reaches a maximum of 3,300 m in the center. The bedrock surface below the ice sheet is an extensive flat area near sea level, which would rebound by as much as 1,000 m if the ice sheet were to be removed (Figure 1). Precipitation over Greenland generally decreases from south to north, ranging from about 2,500 mm per year in the southeast to less than 150 mm per year in interior northeastern Greenland. The southern high precipitation zone is largely determined by the Icelandic low and the resulting onshore flow which is forced to ascend the surface of the ice sheet. In contrast to Antarctica, summer temperatures on Greenland are high enough to cause widespread summer melting. This results in an ablation zone with negative mass balance all around its perimeter. Ablation rates are highest over the southwestern part of the ice sheet where...
In this essay, the author
- Explains that the greenland ice sheet is the second largest on earth and is about one-tenth the volume of the antarctic
- Explains that the ice sheet covers 1.71 million km2, or roughly 80% of the surface of greenland.
- Explains that greenland's ice sheet is sensitive to a warming climate due to its high albedo and elevated topography.
- Explains that glacial ice appeared first on greenland in the late miocene, but a continent-wide one didn't form until the pliocenic or early pleistocienic ages. the glacier retreated from its last glacial maximum position between 22,000 and 14,000 years ago.
- Explains the current evolution of the greenland ice sheet is dominated by continuing retreat from its little ice age maximum combined with a slower trend resulting from older climate changes and changes in basal-ice properties.
- Explains that the summers of 1998, 2003 and 2006 were record runoff years at levels not seen since an earlier warm period in the 1930s and 1940s.
- Argues that the short-term evolution of the greenland ice sheet is hard to predict.
- Explains that the ipcc ar4 predicts that greenland's contribution to global sea-level rise will be between 1 and 13 cm by 2090–2099.
- Explains that the greenland ice sheet survived the holocene interglacial because it created its own cold surface-climate because of its elevation.
2133 wordsRead More - How Does Warm Affect Glaciers And Ice Caps?opinion essayThe statistics point to one deduction; glaciers are melting. This is based upon the study done by Mernild on the Northern Hemisphere ice caps and glaciers. The overall average of mean change in surface
In this essay, the author
- Opines that glaciers and ice caps are deteriorating because of natural causes, predominantly, and human imposed causes.
- Explains that the greenland ice sheet has decreased by 650 meters squared in the last 16 years.
- Explains that the greenland ice sheet could melt if the air temperature rises by 1.6c, or more from pre-industrialization. ocean currents can redistribute heat or change precipitation patterns.
- Opines that the water cycle will be significantly impacted if gic persist in their reduction, and the influx of water will alter the ph level of the marine ecosystem.
- Explains that the ice that disappears is not a magic trick, and it won't reappear as solid water. the ice-albedo feedback and the mirroring effect contribute to the permanent loss of gic.
- Opines that humans need to take responsibility for the gic's frozen state by making big impact changes in how mankind lives.
- Argues that climates will never cease to change, and the amount of time that it changes for is not a definite.
- Explains that al gore's hockey stick diagram showed a consistent temperature range up until the late 1900s. the medieval warm period was completely deleted and the 1930s were altered to be cooler than recorded.
- Explains that the predictions of gic melting are simply predictions based on computer programs that admit to error. the new zealand climate science coalition found that niwa was incorrect with over half of their results.
- Argues that if glaciers and ice caps continue to lose mass at the same rate, they are in danger of receding to a point of extinction and the effects will influence the average person's life.
- Explains that glaciers and ice caps have a global impact on the planet that humankind inhabits. predictions have faults and may not incorporate enough natural variability into their calculations.
1765 wordsRead More - Hdn Jedccomparative essayThe Woods Hole Oceanographic Institution says, “Sea ice is frozen seawater floating on the ocean.” (para. 1) Even though it is made out of seawater, it contains almost no salt. This is because when saltwater freezes, most of ice is pushed down into the water below. Ice is melting at a faster rate than ever before due to increased co2 emissions and climate change.
In this essay, the author
- Explains that ocean acidification and sea ice melt have increased at astonishing rates since major co2 emissions started during the industrial revolution.
- Explains that sea ice is made out of frozen seawater floating on the ocean, but it contains almost no salt. ice is melting faster than ever before due to increased co2 emissions and climate change.
- Explains that ice melting could have serious consequences, such as rising sea levels and the destruction of endangered animals' habitats.
- Explains that ocean acidification is similar to climate change in that their major cause is manmade carbon dioxide emissions.
- Explains how sea ice melt and ocean acidification are connected in a couple of ways. colder water absorbs co2 more easily than hot water.
- Concludes that sea ice melt and ocean acidification are connected, and that we should decrease co2 emissions to stop the major consequences.
568 wordsRead More - Glaciers In Alaska Research Paperexplanatory essayThe majority of glaciers surveyed in Alaska are melting. Thinning rates in the last several years are more than twice those seen in previous years. Half the water flowing into the oceans, globally, due to the glaciers, is because of the ice melting in Alaska.
In this essay, the author
- Explains that glaciers in alaska and other parts of the united states have shrunk dramatically. if temperatures continue to rise, the ice will melt, and some glacier could disappear completely, which causes sea levels to increase.
- Explains that droughts, surges and sea level rise will put pressure on the tectonic plates and lead to frequent earthquakes.
- Explains that melting glaciers will release dangerous green house gases like methane back into the environment, which will bring rapid climate change.
- Explains that the majority of glaciers surveyed in alaska are melting. thinning rates in the last several years are more than twice those seen in previous years.
- Explains that glaciers in the tropics are receding rapidly and losses accelerated during the 1990s. glacier melting has become very rapid in europe's alps since 1980.
- Explains that the tropical glaciers in africa have decreased in size between 60% to 70% since the early 1900s, while the himalayans have been melting within the last 30 years.
- Explains that antarctica's center is cooling down, but coastal snow and ice sheets are still reducing. the melting of glaciers will cause higher sea levels.
550 wordsRead More - The Greenland Ice Sheetexplanatory essay). That means the deeper the snow and ice goes the more vertical compressed, and stretched horizontally it gets. In the uniformitarian model it shows, it is concluded that storms and short weather cycles would be smoothed and destroyed deeper in the ice by compression and diffusion. Dust bands, are inferred to be annual and can be found near the bottom of the GISP2 ice core. Glaciologists dated the GISP2 core by adding the newly formed layers every year, they have a date of about 85,000 years at the 2800-meter level by tallying the dust bands up. The Creationists made a point a lot of dust is known to have happened in the Ice Age part of the Greenland Ice Sheet. So when the atmosphere is loaded with dust, a storm can lay down multiple dust
In this essay, the author
- Explains that the deeper the snow and ice goes, the more vertical compressed, and stretched horizontally it gets. glaciologists dated the gisp2 core by adding the newly formed layers every year.
142 wordsRead More - The West Antarctic Ice Sheetexplanatory essayThere is evidence that the ice shelf has advanced and receded in the past from ocean floor markings that suggest the movement of ice. Evidence of marine sediments on the continental
In this essay, the author
- Explains that the melting of the west antarctic ice sheet would cause global sea levels to rise 4 to 6 meters and flooding of low lying coastal regions like florida.
- Explains that there is evidence that the ice shelf has advanced and receded in the past from ocean floor markings.
198 wordsRead More - Permafrost Melting and its Potential Impact on Northern Canadaexplanatory essayNorthern Canada, usually experiencing very low temperatures, are now receiving much warmer temperatures which has started to give rise to many issues. One of the main challenges facing Northern Canada due to the warmer weather is the melting of the Permafrost and the destruction that it is causing to both living and non-living organisms. The word ‘Permafrost’ refers to a ground that remains “at or below the freezing point for at least two consecutive years” (Bone, 52). In Canada, almost 76% of the land is occupied by the Arctic and Subarctic regions, which has a combination of continuous, discontinuous and sporadic permafrost (Bone, 52). Continuous permafrost is mostly seen in the Arctic and almost 80% of it remains frozen. On the other hand, discontinuous permafrost is mostly seen in the subarctic and approximately 30% to 80% of the ground is frozen and finally sporadic permafrost is seen in parts of Canada closer to the south and has less than 30% of the ground permanently frozen (Bone, 53). However, in the past few decades, geographers have noticed that the average temperature of the planet is rising faster than it normally used to, which is a direct consequence of global warming. The permafrost has started to degrade causing negative effects on greenhouse gas emissions, man-made structure, vegetation, wildlife, sea ice and the lifestyle of the Inuit people in the North.
In this essay, the author
- Explains that the melting of the permafrost is causing negative effects on greenhouse gas emissions, man-made structure, vegetation, wildlife, sea ice and the lifestyle of inuit people in the north.
- Explains that canada contributes approximately 2% of the world's greenhouse gas emissions. permafrost melting releases greenhouse gases, including co2 and methane.
- Explains that the melting of permafrost can have a significant effect on the amount of co2 and methane that is released to the atmosphere.
- Analyzes the effects of the melting of permafrost on the vegetation in the north.
- Explains that sea ice is also an important natural source of fresh drinking water.
- Explains that the melting of permafrost has a significant effect on the inuit people living in the north.
- Explains that the melting of permafrost is due to global warming, which is mainly a cause of human activities such as the burning of fossil fuels.
- Explains that permafrost thaw ponds in northeastern canada are in the canadian journal of fisheries and aquatic sciences.
- Explains the degradation on a road embankment at umiujaq in nunavik (quebec), canada.
- Describes the james bay area, northern quebec, canada. permafrost and periglacial processes 20.4 (2009): 383-9.
- Explains that cbc news is based on science and technology. arctic permafrost thaw will boost carbon emissions.
- Explains that the melting of permafrost has caused many structural issues due to the warming and cooling of the active layer.
- Explains that the melting of permafrost has put a lot of wildlife creatures' lives in danger.
1665 wordsRead More - How Does Climate Change Affects Glaciersexplanatory essayThe whitechuck glacier which is found in Washington has been retreating rapidly since the end of the "the little ice age" which was a period of colder weather but not a full blown ice a...
In this essay, the author
- Explains that the tasman glacier in mount cook national park has retreated about 180 meters a year and now is retreating even faster.
- Explains that glaciers have been around for millions of years and with the arrival of global warming the chance of a ice age has gotten much smaller.
- Explains that the whitechuck glacier in washington has been retreating rapidly since the end of the "little ice age" and has lost more than half its surface area.
- Explains that the fox glacier is one of the fastest moving glaciers in the world with a funnel shaped top pressuring the snow at the bottom.
1026 wordsRead More