14 nautical raster charts updated
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Monday, October 17, 2016
How climate change triggers earthquakes, tsunamis and volcanoes
Bill McGuire on the influence of climate change on geological systems, the link between episodes of major climate transition and geohazards (2012).
Small changes in the Earth's crust can potentially trigger large hazards such as earthquakes and volcanoes.
Small changes in the Earth's crust can potentially trigger large hazards such as earthquakes and volcanoes.
From The Guardian byBill McGuire
Global warming may not only be causing more destructive hurricanes, it could also be shaking the ground beneath our feet
Devastating hurricane? More than 1,000 lives lost? It must be climate change! Almost inevitably, Hurricane Matthew’s recent rampage across the Caribbean and south-eastern US has been fingered by some as a backlash of global warming driven by humanity’s polluting activities, but does this really stack up?
The short answer is no.
Blame for a single storm cannot be laid at climate change’s door, as reinforced by the bigger picture.
The current hurricane season is by no means extraordinary, and the last few seasons have actually been very tame.
The 2013 season saw no major hurricanes at all and tied with 1982 for the fewest hurricanes since 1930.
This, in turn, is no big deal as there is great year-on-year variability in the level of hurricane activity, which responds to various natural factors such as El Niño and the so-called Atlantic Multidecadal Oscillation, as well as the progressive warming of the oceans as climate change bites harder.
The current consensus holds that while a warmer world will not necessarily mean more hurricanes, it will see a rise in the frequency of the most powerful, and therefore more destructive, variety.
This view was supported recently by Kerry Emanuel, a hurricane scientist at MIT, who pointed to Matthew as a likely sign of things to come.
Debate within the hurricane science community has in recent decades been almost as hostile as the storms themselves, with researchers, on occasion, even refusing to sit on the same panels at conferences.
At the heart of this sometimes acrimonious dispute has been the validity of the Atlantic hurricane record and the robustness of the idea that hurricane activity had been broadly ratcheting up since the 1980s.
Now, the weight of evidence looks to have come down on the side of a broad and significant increase in hurricane activity that is primarily driven by progressive warming of the climate.
For many, the bottom line is the sea surface temperature, which is a major driver of hurricane activity and storm intensification.
Last year saw the warmest sea temperatures on record, so it should not be a surprise.
As Michael Mann, an atmospheric scientist at Penn State University, says: “It isn’t a coincidence that we’ve seen the strongest hurricane in both hemispheres [western and eastern] within the last year.” As the Atlantic continues to heat up, the trend is widely expected to be towards more powerful and wetter storms, so that Matthew might seem like pretty small beer when looked back on from the mid-century.
As with hurricanes, Pacific typhoons and the mid-latitude storms that periodically batter the UK and Europe are forecast to follow a similar pattern in an anthropogenically warmed world.
Storm numbers may not rise, but there is likely to be an escalation in the frequency of the bigger storm systems, which tend to be the most destructive.
An additional concern is that mid-latitude storms may become clustered, bringing the prospect of extended periods of damaging and disruptive winds.
The jury is out on whether climate change will drive up the number of smaller, but potentially ruinous vortices of solid wind that make up tornadoes, although an apparent trend in the US towards more powerful storms has been blamed by some on a warming atmosphere.
Tornadoes, typhoons, hurricanes and mid-latitude storms – along with heatwaves and floods – are widely regarded as climate change’s shock troops; forecast to accelerate the destruction, loss of life and financial pain as planet Earth continues to heat up.
It would be wrong to imagine, however, that climate change and the extreme events it drives are all about higher temperatures and a bit more wind and rain.
The atmosphere is far from isolated and interacts with other elements of the so-called “Earth system”, such as the oceans, ice caps and even the ground beneath our feet, in complex and often unexpected ways capable of making our world more dangerous.
We are pretty familiar with the idea that the oceans swell as a consequence of the plunging atmospheric pressure at the heart of powerful storms, building surges driven onshore by high winds that can be massively destructive.
Similarly, it does not stretch the imagination to appreciate that a warmer atmosphere promotes greater melting of the polar ice caps, thereby raising sea levels and increasing the risk of coastal flooding.
But, more extraordinarily, the thin layer of gases that hosts the weather and fosters global warming really does interact with the solid Earth – the so-called geosphere — in such a way as to make climate change an even bigger threat.
Japan Earthquake: Helicopter aerial view video of giant tsunami waves
This relationship is marvellously illustrated by a piece of research published in the journal Nature in 2009
by Chi-Ching Liu of the Institute of Earth Sciences at Taipei’s
Academia Sinica.
In the paper, Liu and his colleagues provided
convincing evidence for a link between typhoons barrelling across Taiwan
and the timing of small earthquakes beneath the island.Their take on the connection is that the reduced atmospheric pressure that characterises these powerful Pacific equivalents of hurricanes is sufficient to allow earthquake faults deep within the crust to move more easily and release accumulated strain.
This may sound far fetched, but an earthquake fault that is primed and ready to go is like a coiled spring, and as geophysicist John McCloskey of the University of Ulster is fond of pointing out, all that is needed to set it off is – quite literally – “the pressure of a handshake”.
Perhaps even more astonishingly, Liu and his team proposed that storms might act as safety valves, repeatedly short-circuiting the buildup of dangerous levels of strain that otherwise could eventually instigate large, destructive earthquakes.
This might explain, the researchers say, why the contact between the Eurasian and Philippine Sea tectonic plates, in the vicinity of Taiwan, has far less in the way of major quakes than further north where the plate boundary swings past Japan.
In a similar vein, it seems that the huge volume of rain dumped by tropical cyclones, leading to severe flooding, may also be linked to earthquakes.
The University of Miami’s Shimon Wdowinski has noticed that in some parts of the tropics – Taiwan included – large earthquakes have a tendency to follow exceptionally wet hurricanes or typhoons, most notably the devastating quake that took up to 220,000 lives in Haiti in 2010. It is possible that floodwaters are lubricating fault planes, but Wdowinski has another explanation.
He thinks that the erosion of landslides caused by the torrential rains acts to reduce the weight on any fault below, allowing it to move more easily.
It has been known for some time that rainfall also influences the pattern of earthquake activity in the Himalayas, where the 2015 Nepal earthquake took close to 9,000 lives, and where the threat of future devastating quakes is very high.
During the summer monsoon season, prodigious quantities of rain soak into the lowlands of the Indo-Gangetic plain, immediately to the south of the mountain range, which then slowly drains away over the next few months.
This annual rainwater loading and unloading of the crust is mirrored by the level of earthquake activity, which is significantly lower during the summer months than during the winter.
And it isn’t only earthquake faults that today’s storms and torrential rains are capable of shaking up.
Volcanoes seem to be susceptible too.
On the Caribbean island of Montserrat, heavy rains have been implicated in triggering eruptions of the active lava dome that dominates the Soufrière Hills volcano.
Stranger still, Alaska’s Pavlof volcano appears to respond not to wind or rain, but to tiny seasonal changes in sea level.
The volcano seems to prefer to erupt in the late autumn and winter, when weather patterns are such that water levels adjacent to this coastal volcano climb by a few tens of centimetres.
This is enough to bend the crust beneath the volcano, allowing magma to be squeezed out, according to geophysicist Steve McNutt of the University of South Florida, “like toothpaste out of a tube”.
If today’s weather can bring forth earthquakes and magma from the Earth’s crust, it doesn’t take much to imagine how the solid Earth is likely to respond to the large-scale environmental adjustments that accompany rapid climate change.
In fact, we don’t have to imagine at all.
The last time our world experienced serious warming was at the end of the last ice age when, between about 20,000 and 10,000 years ago, temperatures rose by six degrees centigrade, melting the great continental ice sheets and pushing up sea levels by more than 120m.
These huge changes triggered geological mayhem.
As the kilometres-thick Scandinavian ice sheet vanished, the faults beneath released the accumulated strain of tens of millennia, spawning massive magnitude eight earthquakes.
Quakes of this scale are taken for granted today around the Pacific Ocean’s “Ring of Fire”, but they are completely out of place in Santa’s Lapland.
Across the Norwegian Sea, in Iceland, the volcanoes long buried beneath a kilometre of ice were also rejuvenated as the suffocating ice load melted away, prompting a “volcano storm” about 12,000 years ago that saw the level of activity increase by up to 50 times.
Now, global average temperatures are shooting up again and are already more than one degree centigrade higher than during preindustrial times.
It should come as no surprise that the solid Earth is starting to respond once more.
In southern Alaska, which has in places lost a vertical kilometre of ice cover, the reduced load on the crust is already increasing the level of seismic activity.
In high mountain ranges across the world from the Caucasus in the north to New Zealand’s southern Alps, longer and more intense heatwaves are melting the ice and thawing the permafrost that keeps mountain faces intact, leading to a rise in major landslides.
Does this all mean that we are in for a more geologically active future as well as a hotter and meteorologically more violent one? Well, no one is suggesting that we will see a great surge in the number of earthquakes and volcanic eruptions.
As always, these will be controlled largely by local geological conditions.
Where an earthquake fault or volcano is primed and ready to go, however, climate change may provide that extra helping hand that brings forward the timing of a quake or eruption that would eventually have happened anyway.
As the world continues to heat up, any geological response is likely to be most obvious where climate change is driving the biggest environmental changes – for example, in areas where ice and permafrost are vanishing fast, or in coastal regions where rising sea levels will play an increasing role.
Freysteinn Sigmundsson of the Nordic Volcanological Centre observes that the centre of Iceland is now rising by more than three centimetres a year in response to shrinking glaciers. Studies undertaken by Sigmundsson and his colleagues forecast that the reduced pressures that result will lead to the formation of significant volumes of new magma deep under Iceland.
Whether this will translate into more or bigger eruptions remains uncertain, but the aviation chaos that arose from the Eyjafjallajökull eruption in 2010 provides a salutary warning of the disruption that any future increase in Icelandic volcanic activity may cause across the North Atlantic region.
Volcanologist Hugh Tuffen, of Lancaster University, is worried about the stability of the more than 10% of active volcanoes that are ice-covered.
He says that “climate change is driving rapid melting of ice on many volcanoes worldwide, triggering unloading as ice is removed. As well as encouraging magma to rise to the surface, leading to increased volcanic activity, removal of ice can also destabilise steep volcano flanks, making hazardous landslides more likely.”
The potential for more landslides is also likely to be a problem in high mountain ranges as the ice cover that stabilises rock faces vanishes.
Christian Huggel of the University of Zurich has warned that “in densely populated and developed regions such as the European Alps, serious consequences have to be considered from [future] large slope failures”.
Looking ahead, one of the key places to watch will be Greenland, where recent findings by a research team led by Shfaqat Khan of Denmark’s Technical University reveal a staggering loss of 272bn tonnes of ice a year over the last decade.
GPS measurements show that, like Scandinavia at the end of the last ice age, Greenland and the whole of the surrounding region is already rising in response to the removal of this ice load.
Andrea Hampel of the University of Hannover’s Geological Institute, who with colleagues has been studying this behaviour, is concerned that “future ice loss may trigger earthquakes of intermediate to large magnitude if the crust underneath the modern ice cap contains faults prone to failure”.
More earthquakes in Greenland might not seem like a big deal, but this could have far wider ramifications.
About 8,200 years ago, an earthquake linked to the uplift of Scandinavia, triggered the Storegga Slide; a gigantic undersea sediment slide that sent a tsunami racing across the North Atlantic.
Run-up heights were more than 20m in the Shetlands and six metres along the east coast of Scotland, and the event has been blamed for the flooding of Doggerland; the inhabited Mesolithic landmass that occupied what is now the southern North Sea.
The submerged margins of Greenland are currently not very well mapped, so the likelihood of a future earthquake triggering a landslide capable of generating a major tsunami in the North Atlantic is unknown.
Dave Tappin, a tsunami expert at the British Geological Survey, points out that one large, undersea landslide has been identified off the coast of Greenland, but suspects that there may not be sufficient sediment to generate landslides as large as Storegga.
Nonetheless, the seismic revival of Greenland is certainly a geological response to climate change that we need to keep an eye on.
The bottom line in all of this is that as climate change tightens its grip, we should certainly contemplate more and bigger Hurricane Matthews.
However, when it comes to the manifold hazardous by-blows of an overheating planet, and especially those involving the ground we stand on, we must also be prepared to expect the unexpected.
Links :
- YouTube : Bill McGuire, author of 'Waking the Giant: How a changing climate triggers earthquakes, tsunamis, and volcanoes', discusses the topics raised in his book.
- Horizon Mag : Scientists investigate how to defend Europe against tsunamis
- The Guardian : Hurricanes will worsen as planet warms and sea levels rise, scientists warn
Sunday, October 16, 2016
Saturday, October 15, 2016
Guirec Soudée explores Greenland for 1 year on his sailboat
Twenty-four-year-old Frenchman Guirec Soudée set out to see the world from a different vantage point: his 30-foot sailboat.
Alone at sea with only his pet chicken, Monique, for company, he is sailing the oceans to fulfill a life-long dream.
Tag along, Monique won't mind.
Friday, October 14, 2016
The great explorers of Islam
Map of the world by Ottoman admiral Piri Reis, drawn in 1513.
Only half of the original map survives and is held at the Topkapi Museum in Istanbul.
The map synthesizes information from twenty maps, including one drawn by Christopher Columbus of the New World
From WorldBulletin (original : Aliomarermes)
The golden period of Muslim geography, travels and explorations involved a vast amount of travel with geographical literature being produced in the world of Islam paving the way for later explorations and discoveries by the Christian West
Arabia being a barren peninsula, its inhabitants had always to depend on foreign supplies for the necessities of life, hence they had to undertake trips to distant countries like Egypt, Abbysinia, Syria, Persia and Iraq.
It was an Arab caravan which brought Hazrat Yusuf (Prophet Joseph) to Egypt.
Moreover, the fertile areas in Arabia including Yemen, Yamama, Oman, Bahrein and Hadari-Maut were situated on the coast, and the Arabs being sea-faring people took sea routes in order to reach these places and fulfilling their commercial ventures.
The birth of Islam opened a new vista for their enterprises and the vast conquests of the Arabs during the early decade of Islamic history served as a fresh stimulus to their adventurous spirits.
The stories of the famous Arabian Nights including the one about Sindbad the Sailor, give a glimpse of the adventures of those fearless Arabs.
Sinbad the Sailor: "Having balanced my cargo exactly..."
Drawing by Milo Winter (1914)
Drawing by Milo Winter (1914)
The Haj or the holy pilgrimage to Mecca was another factor which added to their geographical and commercial knowledge by providing social contacts among the Muslims of various countries visiting Mecca every year.
This pilgrimage provided not only the means for promoting religious unity but also contributed to strengthening the commercial ties among Muslim countries and led to the exchange of views and news among people of far-flung countries.
In fact the Haj, which created an opportunity for a great international assembly each year, has paved the way for Muslim commercial and geographical enterprises.
An overview of the profound contributions to astronomy and navigation
by early Muslim astronomers and scientists
The invention of mariner’s compass opened vast oceans for their enterprising voyages.
Most European writers have credited the Chinese with inventing the mariner’s compass, but according to the famous Orientalist George Sarton, the Arabs were the first to make practical use of it, a fact which has been admitted by the Chinese themselves.
Another celebrated Orientalist, Philip K. Hitti, has endorsed the view expressed by George Sarton.
“According to a statement of Sir R.F. Burton, it even seems that Ibn Majid was venerated in the past century on the African coast as the inventor of the compass”.
l Any way, the practical use of the compass has immensely contributed to the undertaking of distant voyages by Arab sailors, who had hitherto been confined to coastal trips.
They now came out into the open ocean and roamed about in the Atlantic as well as in the Pacific, circled the African continent and touched even the shores of the New World.
The frail boats were replaced by larger sailing ships and Arabs with the help of compass and other marine instruments braved the stormy seas.
A kamal is a celestial navigation device that determines latitude.
It originated with Arab navigators of the late 9th century, and was employed in the Indian Ocean from the 10th century.
Writing in the Legacy of Islam J. H. Kramers says, “Europe ought to look upon them (Muslims) as its cultural ancestors in the domain of geographical knowledge of discovery and of world trade.
The influence which Islam has exercised on our modern civilization in the spheres of action can be seen in the many terms of Arabic origin which are to be found in the vocabulary of trade and navigation.
The measure of influence can only be proved by studying the historical development of the domain over which our actual geographical knowledge extends”.’
An illustration from al-Biruni's astronomical works (973-1048), explains the different phases of the moon.
Theorists
The works of Greek writers specially the Almagest, written by Ptolemy provided the starting ground for Arab geographers.
Al-Khwarizmi, the eminent Arab scientist, who flourished during the reign of the celebrated Mamun-ar-Rashid incorporated some of the ideas of Almagest in his geographical treatise Kitab Surat aL-arz.
The book which has been preserved in Strassburg was edited along with a Latin translation by Nallino.
Kart over Aserbajdsjan fra Ibn Ḵordāḏbehs Bok om veier og kongedømmer
(Kitāb al-Masālik wa l-Mamālik)
by Spruner and Menke - Hand-Atlas für die Geschichte des Mittelalters und die neueren Zeit
Adrabigan on the map of Spruner and Menke.
by Spruner and Menke - Hand-Atlas für die Geschichte des Mittelalters und die neueren Zeit
Adrabigan on the map of Spruner and Menke.
Based on: 1- The Book of Roads and Kingdoms (Arabic: كتاب المسالك والممالك, Kitāb al-Masālik w’al- Mamālik) by the Persian geographer Ibn Khordadbeh, pp. 118 & 119
The simple geographical descriptions of numerous countries including their physical features, climatic conditions and the life of the people formed the subject matter of treatises compiled by early Muslim geographers.
Ibn Khurdabaih wrote Kitabal-Masaalikwal-Mamaalik; Al-Yaqubi compiled Kitab al-Buldan; Ibn al-Faqih also wrote Kitab al-Buldan and Ibn Rusta named his work Kitab al-A’laq al-Nafisa.
These books contained simple facts about the countries in order to satisfy the practical necessities of travellers visiting such countries.
The foremost writer of such geographical treatises during this period was Abu Zaid Al-Balkhi who was an eminent scholar at the court of the ruler of Khorasan.
He has the distinction of being the author of as many as 43 books including his Suwarul-Aqaalim a geographical work of considerable value which is not available at present.
The book guided later writers on the subject.
An 18th Century Persian astrolabe – maker unknown
kept at the Whipple Museum of the History of Science in Cambridge, England.
The points of the curved spikes on the front rete plate, mark the positions of the brightest stars.
The name of each star being labeled at the base of each spike.
The back plate, or mater is engraved with projected coordinate lines.
Abu Yahya Zakariya Ibn Muhammad al-Qazwini (1203-83 A.D.) who wrote a book entitled Ajaib-ulMakhluqat wal-Gharaib-ul-Maujudat which is a very systematic cosmographical work, and which, according to M.
Streck, ‘must be deemed as a work of fundamental importance and is quite the most valuable book that the Arab middle ages have given us in the field’.
Al-Qazwini has dealt with the description of the earth together with its seven climatic regions in his other geographical treatise Athat al-bilad wa-akhbar al-‘ibad (Monument of Places and History of God’s Bondsmen).
The book also contains the climatic regions, physical features, life and history of the people of the countries dealt with.
The voluminous geographical work written by the Spanish author Al-Bakri (C. 1067), contained most elaborate information on ports and coasts.
Another geographer of repute is Hamdullah Mastaufi, the author of Nuzhat-ul-Qulub which deals with natural history, anthropology and geography.
It has helped Mr. G. L. Stange in writing his book entitled Lands of Eastern Caliphate.
Ibn Hawqal's Map of the World. 10th century.
Explorers, Travellers and Writers
Abul Qasim Ibn Hauqal is the first traveller worth mentioning who, starting from Baghdad in 943, A.D. made an extensive tour of the Islamic countries and on his return incorporated his experiences in his geographical treatise, Kitab al-Masaalik-wal Mamaa.
Another more famous traveller of the period is Shamsuddin Abu Abdullah al-Moqaddasi.
Excepting Spain and Sind, Moqaddasi too toured the length and breadth of the Islamic world.
He has put down his travel experiences in his celebrated geographical work Ahsan-al-Taqasim fi Marifat al-Aqaeim a rare book of its type.
A. Sprenger has acclaimed him as the greatest geographer of all ages.
The Asiatic Society of Bengal published the English translation of his famous work in 4 volumes between 1897 and 1910 A.D.
Abul Hasan Ali Ibn al-Husain al-Masudi is one of the great versatile figures of the Islamic world.
Working in the Galata Observatory founded near Istanbul in the late 16th century by the Turkish astronomer Takyuddin, astronomers had access to the best reference works and technology of the era.
Istanbul University library / Bridgeman art library (detail)
He is a well-known writer and explorer of the East.
He was still quite young when he travelled through Persia and stayed in Istakhar for about a year in 915 A.D.
Starting from Baghdad, he went to India, visiting Multan and Mansura, returned to Persia and after touring Kerman again went to India.
Travelling through Cambay, Deccan and Ceylon he along with some merchants sailed to Indo-China and China.
Al-Mas‘udi's atlas of the world
(reversed on the N-S axis to compare with modern geographical maps)
Masudi also visited the southern shore of the Caspian Sea and travelled through Central Asia and Turkistan.
Retiring to Fustat (old Cairo) he wrote his voluminous work Mirat-uz-zaman (Mirror of the Times) comprising 30 volumes in which he elaborately described the geography, history and life of the people of the countries he had visited.
He toured Gujrat in 303 A.H.
According to him, Chemur, a port of Gujrat was inhabited by more than 10 thousand Arabs and their descendants.
Among the great mariners of the 10th and 11th centuries A.D., Sulaiman al-Mahiri and Shahabuddin Ibn Majid occupy outstanding positions.
They not only roamed about in the Indian, Pacific and Atlantic oceans, but also toiled around the African continent and probably even touched the shores of the New World.
Sulaiman reached as far as the Behring Strait and has penned his valuable experiences in a number of books, of which Al-Umdat ae-Mahriya Ji Zabt-ieUlum-il-Bahriya is well -known.
The other mariner Ibn Majid was considered among the four sea lions of his time.
Allama Syed Sulaiman Nadvi in his book entitled The Navigation of Arabs has enumerated fifteen books written by Ibn Majid on Navigation.
According to a Western critic, Ibn Majid is one of the earliest writers of nautical guides and his elaborate geographical account of the Red Sea could not be surpassed even up to the present day.
Ibn Faldan was a traveller of the 10th century A.D., who led an embassy sent by the Abbasid Caliph Al-Muqtadir Billah in 921 A.D.
to the Bulgarian Monarch, and incorporated his experiences in Risalah which is one of the earliest regional accounts about Russia.
During the eleventh century A.D., Abu Rehan Beruni, the celebrated thinker of Islam visited India, stayed there for a number of years, learnt the Sanskrit language and described the geography and the life of India in his memorable work Kitab-al-Hiplel.
Regional geographics were also written during this period.
Famous among them were the description of the Arabian Peninsula by Al-Hamdani and of India by Al-Beruni.
The works of travellers like Ibn Jubayr, Al-Mazini and Ibn Batuta are store-houses of geographical knowledge.
Al-Mazini (1080–1170 A.D.) who visited Russia wrote Tuhfat-al-balad.
Tabula Rogeriana (composite of the 70 tableaux within "The Book of Roger"),
The Nuzhat al-mushtāq fi’khtirāq al-āfāq (also known by it’s Latin name,
Tabula Rogeriana) is a map of what was then the known world made in
1154 by Muhammad al-Idrisi.
In this map, al-Idrisi oriented
South at the top of the map, and the labels (which can be seen better
by clicking on the map and zooming in), are written in al-ʻArabiyyah (Arabic).
The Nuzhat al-mushtāq fi’khtirāq al-āfāq remained the most accurate world map for three centuries.
The most brilliant writer of the period is Al-Idrisi (2101–54 A.D.) who was employed at the court of the Christian king of Sicily.
His book Nuzhat-ul-Mushtag contained 70 maps.
In the second abridged edition of Idrisi’s book one comes across eight instead of seven climates which were to be found south of the equator.
The world map drawn by Idrisi is of the traditional round type and the first translation of his book was published in Rome in 1619 A.D.
Introductory summary overview map from al-Idrisi's 1154 world atlas
(note that South is at the top of the map)
Yaqut-al-Hamavi (1179–1229A.D.) compiled a big geographical dictionary named Mujam-al-Buldan which contains all geographical names in alphabetical order.
It was published in 6 volumes in Leipzig (Germany) between 1666–73 A.D.
Writing in the ‘Introduction to the History of Science; George Sarton remarks, “The Mujam al Buldan is one of the most important works of Arabic literature. It is a store house of information not simply on geography, but also on history, ethnography and natural history. It is preceded by an introduction dealing with mathematical, physical and political geography, the size of the earth, seven climates, etc.”‘
The Spanish traveller, Ibn Jubayr visited Mecca and Iraq in 1192 A.D.
He wrote his well-known book of Travels entitled Rihlat-ul-Kinani which is a unique book of its type in Arabic literature.
Abu Abdulla Muhammad (1304–78 A.D.), better known as Ibn Batuta was the greatest Muslim traveller.
Born in Tangiers, he started his travels at the age of 20, and returned home at the age of 51.
During these 31 years he covered about 75,000 miles which is equal to three trips round the globe.
No explorer or traveller during mediaeval times had traversed so many miles during a lifetime.
Starting from Tangiers he toured Egypt, Abbysinia, Northern and Eastern Africa including Mombassa.
He crossed the great Sahara (Desert) and reached Timbuktu.
He describes an oasis in the Sahara (Desert) where people constructed houses of rock-salt roofed with camel skins.
In Europe he visited Spain, the Eastern Roman Empire and Southern Russia and sailed in the Mediterranean and the Black Seas.
There hardly was a Muslim country in Asia, which Ibn Batuta had not seen.
He made many tours of the Arab countries and performed Haj (Holy pilgrimage to Mecca) four times.
In addition he travelled in Persia, Turkistan, Afghanistan, India, Maldives, Ceylon, East India, Indo-China and China.
According to him Aden was a great commercial centre in those days and had a good system of water-supply.
He travelled as far North as Bolghar (54 degrees N) in Siberia, in order to see the shortness of summer nights and desired to travel into the land of darkness (extreme North of Russia), but abandoned his visit due to certain reasons.
He stayed for eight years in India, as the State Qazi of Muhammad Tughlaq in Delhi, but had to flee to Deccan in order to save himself from the indignation of the Emperor.
He took part in the conquest of Goa and visited Mal dives where he was made Qazi and married four wives.
He relates interesting stories about India.
Hindus in those days drowned themselves in the sacred waters of the Ganges in order to gain Baikunth (Paradise).
On his first sight of Sati he was so overwhelmed with emotion that he almost fell off his horse.
He met a very old man in the Hindukush Mountains, who was said to be 358 years old and got a new set of teeth after every 180 years.
Explorers (English) from MOSTI
Explorations and Discoveries
Muslims may claim due share in the exploration of vast oceans and the discoveries of far off lands.
But the difficulty is that the achievements of Muslims in this sphere of human activity are not generally known to the world.
The largest collection of literary and artistic treasures accumulated during the five centuries of the Islamic rule, perished at the time of the fall of Baghdad.
The invaluable manuscripts were consumed to ashes by Hulagu Khan and his Mongol hordes.
The cream of Muslim civilization met a similar fate in Spain, at the hands of Christian conquerors.
Modern research has now begun to lift the veil from the face of mediaeval ages and the achievements of the Muslims now are revealed in all their glory.
Map of the Persian Gulf from a 8-9th century AH (14-15th century AD) Persian translation by al-Istakhri at the Central Library, Tehran University.
“At a time when Europe firmly believed in the flatness of the Earth,” says Ameer Ali, “and was ready to burn any foolhardy person who thought otherwise, the Arabs taught geography by globes”.
Their progress in mathematical geography was no less remarkable.
The works of Ibn Hauqal, Makrizi Istakhri, Masudi, Beruni, Idrisi, Qazwini, Wardi and Abul Fida contain store of geographical knowledge specially on this branch of science, called by them “Rasnul Ard”.
Rotation of the Earth
The rotation and sphericity of the earth were discussed and proved by the Muslim geographers of mediaeval times.
The Kitab Kalimat-ul-Ain deals with the rotation of the earth which causes day and night.
Muslim astronomers also proved that the earth is a sphere and has a shape like a peach.
Globes were commonly used in Arabic schools of mediaeval times which testifies to the contention of the sphericity of earth advanced by Muslims.
Geography of the world was also taught with the help of globes in Moorish Spain.
Knowledge of Seas
Arab Mariners and explorers had a very wide knowledge of seas and oceans.
The greatest discovery of the Arabs was that the oceans are connected with one another and form a compact oceanic world.
The first sea route described by Sulaiman al-h-Mahiri started from the Indian Ocean and passing through the Pacific Ocean, Behring Sea, Arctic Ocean and Atlantic Oceans entered the Mediterranean Sea through the Straits of Gibraltar.
The other route was easier.
Starting from the Indian Ocean and passing through the Abbysinian Sea, Mozambique channel and encircling the Cape of Good Hope it entered’ the Atlantic Ocean.
Passing through the Straits of Gibraltar it entered the Mediterranean Sea.
This was the route used by Vasco De Gama in 1498 A.D.
This shows that the Arabs were the masters of the seas and possessed maps of seas and oceans which they freely used in their voyages.
Ibn Khaldun has stated the length of the Red Sea, to be 1,400 miles, while according to current maps it is given as, 1,310 miles.
This shows that the speculations of Arab geographers came very close to modern research.
Behring Strait
The Behring Sea and Strait was known to the Arabs.
The route described by Sulaiman al-Mahiri went from the Pacific Ocean to the Arctic Ocean passing through the Behring Strait.
The celebrated explorer Al-Masudi has also mentioned the Behring Sea in his works.
Among the Arabs it was known as ‘Warang’ sea.
According to the Encyclopaedia of America the geography of equatorial Africa and the issuing place of the river Nile was known to the Arabs for a very long time.
Arab Pilot of Vasco De Gama
In 1498 A.D. Vasco De Gama discovered a new route to India by passing through the Cape of Good Hope.
Prince Henry of Portugal had established his nautical academy at Cape St. Vicent under the guidance of Arab and Jewish teachers which prepared the ground for the explorations of Vasco De Gama.
It is now a well-known fact that an Arab had piloted his ship to India.
Writing in Legacy of Islam, J. H. Kramers says, “when Vasco De Gama, after his circum-navigation of Africa in 11198, had reached Malindi on the East Coast of Africa, it was an Arab pilot that showed him the way to India.
According to Portuguese sources, this pilot was in possession of a very good sea-map and of other maritime instruments.
Arabic sources of that time also knew the story; they state that the Pilot, whom they knew under the name of Ahmad Ibn Majid, could only be induced to show the way to the Portuguese after having been made drunk”.
Reporting from Bares, a Portuguese who was a member of the party ofVasco De Gama, writes in the Encyclopaedia of Islam: “When Vasco De Gama reached Malindi a Moor (Arab Muslim) called on him.
Being much pleased in our company and with the idea of winning the favour of the king of Malindi who was in search of a pilot for the Portuguese ship, he (Arab Muslim) agreed to pilot our ship to India“.
According to the earned author of the Encyclopaedia Britannica, a local hand had piloted the ship of Vasco De Gama to India.
He is either shy of associating the name of a Muslim with the much advertised exploration of Vasco De Gama or is ignorant of such a vital fact which may hardly be expected from an author who has undertaken such a gigantic work.
The discovery of-America
Modern research has proved beyond doubt that the Arabs discovered America.
Muslim Geographers and astronomers believed in the sphericity of the earth.
The trigonometrical tables of Khwarizmi were translated by Adelard of Bath, Gerard of Cremona and Roger Bacon.
The famous book Image Mundi published in 1410 A.D. incorporated the Ain (or Arim) theory from the translations of Khwarizmi.
It was from this book that Columbus learnt that the earth was pear shaped and that there must be some elevated part on the other side of the earth which he decided to discover.
“Thus Islamic geographical theory”, observes J. H. Kramers, “may claim a share in the discovery of the new world”.
Modern research on the subject has gone a step further and has established that the Arabs discovered America five centuries before Columbus.
The following important news was published in leading Indian newspapers including the Delhi Express, dated 11th August 1952.
“A leading South African anthropologist says the Arabs, not Christopher Columbus discovered America. The Arabs scored a beat of nearly 500 years on Columbus, according to Dr. Jeffreys, Senior lecturer of Social Anthropology at Witwatersand University. Dr. Jeffreys based his claim on a discovery 18 months ago of Negro Hamitic skulls in the Rio, Grande River.”
The professor said, ‘Puzzling things previously inexplicable suddenly made sense and fitted a jigsaw puzzle’.
“Dr. Jeffreys thinks that by 1000 A.D. Arabs already commanded the Mediterranean, were established on the West coast of Africa and had settled in America. Columbus, too, found small colonies of Negroes in the Darian Isthumus who, according to Dr. Jeffreys, were descendants of Arab slaves.”
“He said the discovery of Hamitic skulls in caves in Bashama Islands and African root crops in the Caribbean lend credence to this theory.”
The celebrated anthropologist of South Africa, Prof M. D. W. Jeffreys’ article has been published in various journals of the world in which he has given weighty proofs that Arabs had discovered America and had settled in Caribbean islands long before the arrival of Columbus.
He says, “There is an old Portuguese tradition that when the Portuguese were exploring the coasts of Guinea (West Africa) under King John II, who died in 1495, these explorers brought maize, an American plant from Guinea to Portugal….
As maize must have reached Guinea from America to introduce it to Portugal before Columbus sailed from Spain, it is clear someone must have brought it from the Americas, and I claim it were the Arabs who did so”.
In the same way banana was carried by Arabs to Caribbean islands and American mainland.
Peter Martyr, a friend of Columbus, published his first Decade before 1504 A.D.
In it he describes the banana as it appeared in the West Indies when the Spaniards arrived.
He writes: “it (banana) was brought from a part of Ethiopia called Guinea, where it grows wild, as in its native country.” It was the Arabs who introduced the banana to Guinea (West Africa) and there from carried it to Caribbean islands and American mainland.
Reynold writes: “The Arabs were instrumental in distributing the banana across equatorial Africa, so that it was well-established on the Guinea coast when the Portuguese first explored there in the years 1469-1474 A.D.”
Moreover the Atlantic islands were known long before the discovery of Columbus.
The Arabic names of these islands in the geography published by a Franciscan Friar in 1350 A.D.
prove that most of these were inhabited by Arabs and their descendents, e.g. Lost Islands were named Kalidat, Teneriffe was named Elburd.
The word Brazil too has Arabic origin.
Armando Cortesao, formerly counsellor for the History of Science at UNESCO has published a book called The Nautical Chart of 1424, in which he has named several islands which have Arabic origin e.g. Antilia, Saya and Ymana.
The celebrated Geographer Idrisi had published his well-known geography Nuzhat-al-Mushtaq about 1151 A.D. : Idrisi in his geography gives a hint that the Arabs knew the Americas.
The Western Orientalist Glas, writing in 1764 A.D. of Idrisi, whom he -calls the Nubian geographer admits: “Anyone who reads with attention the first part of the Nubian Geographer’s Third Climate will be strongly inclined to believe that the Arabs had even some knowledge of America or West India Islands .
Links :
- Aquila : Islamic contributions to astronomy and navigation
- Kaust musum : contributions made by Muslim scholars to astronomy and navigation
- Islam in Indonesia : Muslim contribution to astronomy
- Aramco World : Arabic in the sky
- Cartography unchained : About Al-Idrisi; The Book of Roger 'Orphan' Circular World Map
- Muslim Heritage : Astronomical Observatories in the Classical Islamic Culture
- The Guardian : So Muslims beat Columbus to America? They had better get in line
- The History of the Discovery and Conquest of the Canary Islands
- The Pre-Columbian discovery of the American continent by muslim seafarers by Fuat Sezgin
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