Announcements:

Prof. Dr. Ali Polat

Title : How did the Earth form?

Absract:The Earth is one of four rocky planets in the Solar System and is located about 149 million km away from the Sun. The Earth is a unique planet in that it is the only planet possessing a large volume of liquid water (oceans), oxygen-rich atmosphere, life, plate tectonics, and continental and oceanic crust. Many scientists and philosophers attempted to explain the origin of our planet. It became clear in the 16th and 17th centuries that the Earth was part of the Solar System and formed approximately at the same time with the Sun and other planets. The currently accepted theory for the Solar System is the “nebular theory”, which is originally proposed by the German scientist Immanuel Kant (1724-1804) and the French scientist Pierre-Simon, marquis de Laplace (1749-1827). According to the present-day version of this theory, the Solar System was formed about 4.6 billion years ago by the collapse of interstellar nebula, consisting mainly of hydrogen and helium gases (98%) and dust (2%). When the gravitational balance of the nebula was disturbed, probably by a nearby supernova explosion, the gas and dust cloud began to collapse and rotate in an anti-clockwise direction turning into a disk shape. Because of the law of conservation of angular momentum, as the collapse and contraction continued the rotation of the disk became faster and faster, concentrating about 99.85% of the mass at the centre to form the proto Sun. The remaining 0.15% gas and dust condensed to form the planets, satellites, comets and asteroid belt. Because of the law of conservation of energy, the nebula heated up as it contracted. The solar winds from the proto Sun removed the reaming volatile molecules (mostly hydrogen compounds) from the inner to the outer parts of the Solar System. When the temperature reached 10 million degrees Celsius (°C) in the core of the proto Sun, nuclear fusion started by hydrogen burning to produce helium, and the Sun was born as a star. Composition of the planets depends on their distance from the Sun because condensation temperature of molecules decreases from inner to the outer Solar System. Because of high temperature (1300 – 100 °C) conditions inside the frost line, mostly refractory silicate particles and metal oxides could condense in the inner Solar System. These silicate particles and metal oxides collided to form planetesimals, and planetesimals, in turn, accreted to form the rocky planets including Mercury, Venus, Earth, Mars, and the asteroid belt. When the Earth was 40-50 million years old, a Mars-sized planet (Theia), sharing the same orbit with the Earth, collided with it, resulting in the formation of the Moon. Following its accretion, the Earth underwent chemical and physical differentiation processes, leading to the formation of the crust, mantle, core, hydrosphere and atmosphere. Volatile hydrogen, carbon and nitrogen compounds (H2O, CO2, CH4, HN3) condensed at lower temperatures (<-120°C) outside of the frost line, resulting in the formation of giant gas planets including Jupiter, Saturn, Uranus and Neptune.

Biography

Kanada Yerbilimleri Dergisi Başeditörü Bilim Akademisi Üyesi
Doğum yeri ve yılı:
• Elazığ, Keban ilçesi, Denizli köyü, 1963
Yüksek eğitim ve öğretim hayatı:
• 1984-1988: İstanbul Teknik Üniversitesi, Jeoloji Mühendisliği Bölümü
• 1988-1989: İngiltere’de İngilizce dil eğitimi
• 1990-1992: ABD, Houston Üniversitesi yüksek lisans (mastır) çalışması
• 1994-1998: Kanada, Saskatchewan Üniversitesi doktora çalışması
• 1998-2001: Almanya, Max-Planck Enstitüsü yerkimyası araştırmacısı
• 2002-2019: Kanada, Windsor Üniversitesi jeoloji profesörü
Aldığı ödüller
• 1998: Almanya Alexander von Humboldt Kurumu Genç Araştırmacı Ödülü
• 2000: Almanya Max-Planck Topluluğu Genç Araştırmacı Ödülü
• 2003: Ontario Eyalet Hükümeti Üstün Yetenekli Genç Bilim Adamı Ödülü
• 2010: Windsor Üniversitesi Fen Fakültesi Dekanlık Özel Ödülü
• 2011: Geology Dergisi En İyi Bilim Hakemliği Ödülü
• 2012: Geology Dergisi En İyi Bilim Hakemliği Ödülü
• 2013: Precambrian Research Dergisi En İyi Bilim Hakemliği Ödülü
• 2014: Kanada Jeoloji Birliği W.W. Hutchison Bilim Madalyası
• 2014: Çin Halk Cumhuriyeti Milli Eğitim Bakanlığı Üstün Yetenekli Yabancı Bilim Adamı (Changjiang) Ödülü
• 2015: Windsor Üniversitesi Fen Fakültesi Bilim Ödülü
• 2015: Windsor Üniversitesi Bilim Ödülü
• 2018: Çin Halk Cumhuriyeti Wuhan Yerbilimleri Üniversitesi Kürsü Profesörlüğü Ödülü
Bilimsel eserler
• Uluslararası dergilerde yayınlanmış 100’den fazla bilimsel makale
• Altı jeoloji kitabının yazımına katkı
• Uluslararası konferanslarda sunulmuş 70 tane bildiri
• 20 tane teknik rapor
Makalelerin aldığı atıf sayısı: 6400
Bilimsel araştırma kurumlarında bilirkişi olarak görev yaptığı ülkeler
• Kanada, ABD, Almanya, Avusturya, İsvicre, Belçika, Hollanda, Kazakistan ve Çin Halk Cumhuriyeti
Araştırma yaptığı ülkeler
• Kanada, Grönland, Almanya, Türkiye, ABD (Alaska), Çin Halk Cumhuriyeti, Mısır