River of ice

Lambert - Fisher Glacier, Antarctica. Image from Google earth

 

 

Glacier is a moving mass of ice. It is different to iceberg in that, it moves over land and is much larger in size. The term “glacier” is from the French word ‘glace’, which has been taken from latin word ‘glacies’, both meaning ice.

Glaciers are formed due to snow fall and accumulation of ice over longer periods of time. With increasing snowfall, ice accumulates in glaciers. This leads to two different processes in a glacier formation. First is the process of compression within the glacier. It makes the glacier much denser and heavier. Secondly, increased weight of the glacier makes it move downwards, towards a lower area.

While moving down, glaciers erode and deposit, thus creating many features. Antarctica, Greenland, Alaska, Himalayas are some of the regions with glaciated landscapes.

Why are glaciers relevant?

Though, the relevance of a glacier may be mainly as a vacation spot for people not living in its vicinity. Glaciers are much more than that. It is relevant to human life economically, environmentally as well as socially.

It is very difficult to assess the tangible economic value of a glacier for a nation or state. But it a priceless resource with immense direct and indirect values. Its importance can be analysed from a 2014 report by U.S. Geological Survey economists Catherine Cullinane Thomas and Christopher Huber and National Park Service economist Lynne Koontz. The report is about the economic gains from Glacier national park in 2014. The report shows the one year benefits received from the glacier park to the economy, in form of income and the employment generated in the area. This study is not only the single example of the economic relevance of a glacier. In reality, there are immense benefits and gains which are still not explored.

Environmentally, glaciers provide nutrients to soils, rivers, lakes and oceans. They are a great source of fresh water and has an important role in maintaining the water balance in climate. They are also important in maintaining the salinity level of the oceans. Infact, if we realise, glaciers are a relevant part of the whole environmental balance of nature. A minor change in this natural equilibrium may disrupt the whole system.

Khumbu Glacier- Highest glacier in the world. Image from Google Earth

 

Glaciers are relevant socially as well as culturally. They are sites of powerful sacred and symbolic meanings for local communities (Allison 2015). A study by Allison (2015) shows the spiritual connection of the communities in the Peruvian Andes, the Nepalese Himalaya, and the Meili Snow Mountains of Yunnan, China to the glaciers. Glaciers are source of many important rivers which are considered sacred by its masses.

Some Facts about Glaciers -

Largest glacier in the world - Lambert-Fisher Glacier in Antarctica, 400 km long, and up to 100 km wide.

Highest glacier in the world - The Khumbu glacier in north-eastern Nepal. Its elevation is 4,900 m at its terminus to 7,600 m at its source.

Oldest glacier – The oldest glaciers ice can be found in Antarctica which is about 1,000,000 years old. In Greenland it is more than 100,000 years old.

References –

Allison, Elizabeth. (2015). The spiritual significance of glaciers in an age of climate change. Wiley Interdisciplinary Reviews: Climate Change. 6. 10.1002/wcc.354.

Decoding the satellite image - Baitarni Estuary, India.

LISS III image Baitarni Estuary, Odisha

The LISS III satellite image is acquired from Bhuvan portal by National Remote Sensing Centre, ISRO, Government of India, Hyderabad, India.

Decoding the Satellite image -

Google Earth Image of Baitarni Estuary, Odisha

The LISS III image is taken on February 2018. As you can see, it is not a natural colour image. A natural colour image of the same region will not have much brighter colours, like the Google Earth image given here. The hues of the features have the same shades as it is present in the nature. However, it is somewhat difficult to distinguish the features as all the colours merge into each other.

The colourful image i.e. the LISS III satellite image is a false colour composite (FCC). The regular RGB bands are not used in a FCC image, instead other band images are taken. In the FCC image here Red, Green and Infra-red band has been used. The FCC image highlights the features with bright shades which reveal lots of information. LISS III is a multi-spectral sensor employed in ISRO's Resourcesat satellites which capture images in visible and infra-red bands.

In this LISS III image, many distinguishable features in bright shades are visible. One can easily distinguish between the triangular landmass and surrounding water feature in the region by the tone and texture of the features. Another distinguishable feature here is the curvy, meandering bright blue Baitarni river dissecting the landmass. The dissimilar shades of blue in different section is due to presence of suspended particles and sediment brought by the river. As it falls into the Bay of Bengal, the extent of the suspended sediments is clearly visible in different shades of the sea.

Kanika sand island is visible in the Bay of Bengal as bright red patch, east of the main landmass. It is a densely vegetated mangrove forest confirmed by the bright red shade in the FCC. In the mainland, two major and many minor bright red patches are also discernible. The patches are in dissimilar shade/tone of red owing to type, health, and density of vegetation in the region. The two major patches are forested part of the Bhitarkanika national park and wildlife sanctuary. In the northern part of the mainland, cyan/turquiose toned small sized specks of land along the river are the settlements.

Monsoon Culture across the World.

What is Monsoon?

The word monsoon is derived from the Arabic mawsim (meaning “season”) and has come to mean a seasonal reversal of winds. In summer, the land get heated quickly as compared to water, resulting in general sea to land movement called onshore flow. Reverse happens in winters, as the land is cooler than the surrounding water bodies leading to general land-to-sea movement called offshore flow. The monsoon wind circulation also has a seasonal precipitation pattern with moist onshore flow in summer and dry offshore flow in winters.

Where is Monsoon found?

Monsoon are predominently associated with South Asian regions. However, it also occurs in east Asia, western Africa, northern part of Australia and Pacific coast of Central America.

Monsoon in Kerala, India. Image by Ambady Sasi, Pixaby

Monsoonal Character and Culture across the World

Meghalaya, India (South Asian Monsoon)

The name literally mean the land of the clouds. It has two of the most wettest places in the world. Monsoon starts here by mid of May and continues up to the month of September and October. The monsoons increase the natural beauty of the State. The stretches of valleys and highland plateaus becomes misty and cloudy making it analogues to Scotland. The State has many lakes, waterfalls, brooks and gardens. The tallest plunge waterfall in India, the Nohkalikai Falls, goes through a spectacular makeover during the monsoons. The residents of the region are not afraid by heavy rainfall but have adapted their lives with knups and living root bridges.

Knups are traditional Khasi umbrellas, made from bamboo and banana leaves, to continue living their lives and earning livelihood during incessant rain and strong winds.

Living root bridges found in many villages of Meghalaya are great examples of sustainable local architecture.

A double-decker living root bridge in Nongriat, Meghalaya. Photo courtesy Arshiya Urveeja Bose.

Kyushu Islands, Japan (East Asian Monsoon)

The climate of Japan is quite diverse ranging from temperate climate in northern Island to humid, tropical conditions in southern parts. Kyushu Island lies in Southernmost island of Japan. The monsoonal season in Kyushu Islands in Japan usually starts from end of May or start of June to mid July. The weather during the rainy season is unstable and unpredictable.

The Japanese word for rainy season is tsuyu, literally “plum rain” (梅雨), as it coincides with the season of plums ripening in Japan.  Another benefit of the rainy season is that many flowers bloom during this time. One of them is ajisai (hydrangea), which is a symbol of Japan's rainy season. A variety of irises also blooms during this season and can be seen on view in many gardens and parks.

Hydrangea, the flower of the Japanese rainy season. Image courtesy -Takuyo (Pixabay)

The rainy season is considered as a gloomy time in Japan, that's why this period is generally avoided for tourism. In the urban life like city of  Fukuoka, umbrella become a unavoidable companion. There are also many indoor activities to keep people occupied in gloomy tsuyu season. Rain, mudslide and floods also affect the life of people during heavy rainfall during monsoons.

Darwin, North Australia (Australian Monsoon)

Summer monsoon in Darwin, Australia is different from rest of the world. The region receives its major rainfall through monsoons from december to april. Thunderstorms and high relative humdity are common occurance in the season.

Monsoon play a major role in setting up the natural ecostystem of the place which is quite different to that of non-monsoonal southern regions. Extensive wetlands, natural savanna vegetation and native wildlife has assisted in establishing three national park and extensive parks and gardens in Darwin. Tourism is the major industry and employment sector in Darwin.

Escarpment and wetlands in Kakadu national park, Darwin. Image courtesy - Tourism NT

Liberia, West Africa (African Monsoon)

Liberia lies in the south facing coast of western Africa. The monsoon season in Liberia starts from May and continues up to the month of October. The climate during monsoon season is humid but not so hot. Main vegetation in the coastal parts of the region is mangroves. As one moves towards the inner parts of the country, tropical forests are found. In more interior dry parts of the country, grassland are found. The climate of Liberia is much moderate and humid as compared to the interior hot dry Sahara region because of monsoon.

Ross (1919) has written about the monsoons and its effect on Liberia in his research -

The rains have an important influence on the life of the country in relation to travel, transportation, communication and food supply.

Native Architecture of Liberia, Adapted to heavy monsoons. (Ross,1919)

He further writes about the life of the natives and the foreigner settlers during monsoon -

The season of rains is probably the most pleasant one for Europeans. There are few days during that season when the feeling is one of "stickiness" and great oppression, but such days are not common. The daily temperature range is from 3° to 10° F. A fire in an open grate, if a grate has been built into a house, as is infrequently the case, is a rather happy thing; its genial effect is more in drying out the house than in directly furnishing warmth. The natives are often sufferers from cold on rainy days and sit around the little fires that kept eternally going within their mud-walled houses.

Arizona, United State of America (Central American Monsoon) -

The summer monsoon in Arizona, USA is from July to mid of September. The monsoons here are charactersied by high temperatures, high winds and thunderstorms accompanied by gustnadoes, dust storms and sometimes tornadoes. Visibility is reduced because of dust storms. 

Dark Monsoonal clouds visible over Tuscon, Arizona. Image by Philip,Pixabay

Flash Flooding is also a common occurrence due to brief but heavy downpours. This can lead to dangerous circumstances and government has passed the Stupid Motorist Law, which may lead to charging the rescue cost from the motorist who has entered a flooded area of roadway.

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Reference

Ross, Emory. “The Climate of Liberia and Its Effect on Man.” Geographical Review, vol. 7, no. 6, 1919, pp. 387–402. JSTOR, www.jstor.org/stable/207671. Accessed 8 July 2020.