IODP 355 Moratorium Proposal: Cenozoic evolution of the Asian Monsoon: tectonic-climate interactions

Lead Research Organisation: University of Birmingham
Department Name: Sch of Geography, Earth & Env Sciences

Abstract

The Asian Monsoon is one of the most dramatic climatic phenomena on Earth today. Almost two thirds of humanity live within regions influenced by the monsoon and the strength and variability of the annual rains are crucial to the prosperity of the region. Understanding what controls what controls the Asian monsoon and how it has changed in the past is important not only to scientists but also the general population.

The intensity of the modern monsoon likely reflects the fact that the HTP is the largest mountain chain seen on Earth for more than 500 million years. This huge tectonic forcing has correspondingly made a particularly large impact on the planet's atmospheric systems. However, this proposed relationship is the basis of a long-running debate. To confirm the relationship between the HTP and the strength of the Monsoon scientists need continuous geological sequences which have recorded the relatively slow growth of the plateau and monsoon strength dating back to the collision of the Indian and Asian plates around 50 millions years ago. Such records exist in the oceans around Asia and are now being drilled by the International Ocean Discovery Programme (IODP).

The onset and intensification of the monsoon allied with the tectonic evolution of the Himalayan-Tibetan Plateau (HTP) comprises perhaps the most significant processes affecting global climatic conditions during the Cenozoic, but the lack of explicit evidence for a causative relationships remains a major problem in Earth science. Demonstrating any linkage between climate and tectonics is impossible without a better understanding of when and how the monsoon developed. With this information, such developments can then be correlated, or not, to either tectonic uplift and extension, or other possible Cenozoic climate drivers. As an example, chemical weathering of the HTP and associated initiation of the monsoon has been invoked as a mechanism that draws down atmospheric CO2 , suggesting this weathering to be an integral part of the Cenozoic climate system. Studies have highlighted a significant climate change at ~8 Ma, and at ~23 Ma it has been argued these represent monsoon intensification. On the other hand, alternative models propose the retreat of shallow seas from Central Asia (Paratethys) is a crucial boundary condition influence, while other workers have argued the strengthening of the monsoon is linked to either; opening of the South China Sea, formation of the Western Pacific Warm Pool or global cooling.

Resolving such paleoclimatic questions is critical to answer questions over the future response of the Monsoon to anthropogenic warming. Specifically it is necessary to deconvolve the signals of: a) Monsoon response to baseline changes in relief and extent, driven by uplift and solid Earth process from: b) Monsoon response to key periods of elevated CO2 and global warmth during the late Cenozoic, e.g. the Mid-Pliocene Warm Period (MPWP) at ca. 3.5Myr; the Middle Miocene Climatic Optimum (MMCO) at ca. 18-15 Myr and Early Eocene at ca. 48-56 Myr.

Planned Impact

INDUSTRIAL IMPACT
An advantage of this project is the related CENTA NERC DTP PhD project, awarded to Kate Newton, includes a CASE placement with Isoprime. Compound specific (delta-D and delta-13C) and carbonate (delta-18O) stable isotope ratio mass spectrometry (IRMS) based analyses are the key analytical approaches for this project. Based in Manchester, Isoprime is solely dedicated to producing the most sophisticated IRMS systems in the world. The DR Kate Newton will work with Isoprime applications scientist Dr Rob Berstan to gain training, insights and experience of cutting edge IRMS capabilities, with the opportunity to apply the latest techniques to targeted samples from the project. The DR will also gain a broader appreciation of how their analytical skills can be relevant to a range of research or employment areas in geology, hydrology, food authentication, forensics, medicine and environmental sciences.

EDUCATIONAL and STAKEHOLDER IMPACT
Cenozoic palaeoceanographic research embodies international scientific collaboration and the deployment of specialized engineering and technological solutions against a backdrop of dramatic ocean environments. This strong aesthetic appeal gives scientists leverage for communicating their work to the public, including young people, educators and policy makers.

This moratorium proposal will fund a technician post to be shared by two individuals who have undertaken a number of Undergraduate Research Bursary (IODP-URB) with Bendle's lab in Birmingham. The aim of the IODP-URBs are to provide lab-based research experience for undergraduates aiming to develop research skills and have the potential to go onto postgraduate education. We wish to provide an additional opportunity via the technical post.

Lapworth Museum: We are planning to a new section dedicated to Cenozoic climaes hosted and an Eocene Climates workshop which will take place in the newly refurbished Lapworth museum (funded by National Lottery, alumni and donor contributions at a cost of ca.£3 million). Public outreach will be a central function of the new-look museum. Our workshop will provide a focus for public engagement.

Project website: We will develop a website for the project that provides details about our science objectives and discoveries, media articles, magazine articles for the public etc.

The above work will build on the PIs legacy of public engagement and outreach efforts to publicize their ocean Drilling related scientific work. For example PI Bendle led media impact in the UK, associated with the publication of Pross et al. 2012 in Nature, with "Palm Trees in the Antarctic" related stories being carried on the main BBC news science page, every major UK newspaper and interviews on BBC Radios 4 and 5. We are already working with the University of Birmingham Press Office to prepare a press pack for the media and policy makers to achieve a similar level of impact.

We plan a series of linked talks on 'Virtually University' (http://www.virtuallyuniversity.org.uk), which is a videoconferencing outreach program that helps to inform Higher Education choices of sixth form students around the country. Through Virtually University we aim to enable students to experience the type of multidisciplinary research and the diversity of study available at university.

To further maximise the potential impact of the proposed research on policy makers the investigators and PDRA will apply to the Royal Society Royal Society Pairing Scheme for MPs, civil servants and scientists.

Publications

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Description Main (shipboard) findings of IODP Expedition 355:
- A major submarine fan draining the western Himalaya and Karakoram since ~17 Ma.
- Heavy mineral assemblages indicate that the Greater Himalayan Crystalline Sequence was fully exposed to the surface by this time (incl. provenance from Indus Suture Zone).
- Pliocene sandy intervals at Site U1456 were deposited in lower fan "sheet lobe" settings, with intervals of basin plain turbidites separated by hemipelagic muddy sections deposited during the Miocene.
-No major active lobe appears to have affected the Laxmi Basin since the Middle Pleistocene (~1.2 Ma).
- < 1.2 Ma, continuous record, millennial scale variation over several glacial cycles can be examined.
- Recovered continuous hemipelagic sections spanning ca.6- 8.5 Ma capturing C4 plant expansion.
- Recovered sediment from a large mass transport deposit (larger than Storegga Slide) measuring ~330 and ~190 m thick at Sites U1456 and U1457, respectively.
Exploitation Route Numerous manuscripts are in prep for peer reviewed submission.
Future grant proposals.
Sectors Education,Environment

URL http://iodp.tamu.edu/scienceops/expeditions/arabian_sea.html