scholarly journals Insights into the recurrent energetic eruptions on Awu, one of the deadliest volcano on earth

2020 ◽  
Author(s):  
Philipson Bani ◽  
Syegi Kunrat ◽  
Devy Kamil Syahbana ◽  

Abstract. The little know Awu volcano is among the deadliest with a cumulative dead toll of 11048. In less than 4 centuries, 18 eruptions were recorded, including two VEI-4 and three VEI-3 with worldwide impacts. The regional geodynamic is controlled by a divergent-double-subduction and an arc-arc collision. In that context, the slab stalls in the mantle, undergoes an increase of temperature and becomes prone to melting, a process that sustained the magmatic supply. Awu also has the particularity to host alternatively and simultaneously a lava dome and a crater lake throughout its activity. The lava dome occurred passively through the crater lake and induced strong water evaporation from the crater. A conduit plug associated with this dome emplacement subsequently channeled the gas emission to the crater wall. However, with the lava dome cooling, the high annual rainfall eventually reconstituted the crater lake and creating a hazardous situation on Awu. Indeed with a new magma injection, rapid pressure buildup may pulverize the conduit plug and the lava dome, allowing lake water injection and subsequent explosive water-magma interaction. The past vigorous eruptions are likely induced by these phenomena, a possible scenario for the future events.

2020 ◽  
Vol 20 (8) ◽  
pp. 2119-2132 ◽  
Author(s):  
Philipson Bani ◽  
Syegi Kunrat ◽  
Devy Kamil Syahbana ◽  

Abstract. The little-known Awu volcano (Sangihe Islands, Indonesia) is among the deadliest, with a cumulative death toll of 11 048. In less than 4 centuries, 18 eruptions were recorded, including two VEI 4 and three VEI 3 eruptions with worldwide impacts. The regional geodynamic setting is controlled by a divergent-double-subduction collision and an arc–arc collision. In that context, the slab stalls in the mantle, undergoes an increase in temperature, and becomes prone to melting, a process that sustained the magmatic supply. Awu also has the particularity of hosting alternatively and simultaneously a lava dome and a crater lake throughout its activity. The lava dome passively erupted through the crater lake and induced strong water evaporation from the crater. A conduit plug associated with this dome emplacement subsequently channeled the gas emission to the crater wall. However, with the lava dome cooling, the high annual rainfall eventually reconstituted the crater lake and created a hazardous situation on Awu. Indeed with a new magma injection, rapid pressure buildup may pulverize the conduit plug and the lava dome, allowing lake water injection and subsequent explosive water–magma interaction. The past vigorous eruptions are likely induced by these phenomena, possible scenarios for future events.


2021 ◽  
pp. 147612702110120
Author(s):  
Siavash Alimadadi ◽  
Andrew Davies ◽  
Fredrik Tell

Research on the strategic organization of time often assumes that collective efforts are motivated by and oriented toward achieving desirable, although not necessarily well-defined, future states. In situations surrounded by uncertainty where work has to proceed urgently to avoid an impending disaster, however, temporal work is guided by engaging with both desirable and undesirable future outcomes. Drawing on a real-time, in-depth study of the inception of the Restoration and Renewal program of the Palace of Westminster, we investigate how organizational actors develop a strategy for an uncertain and highly contested future while safeguarding ongoing operations in the present and preserving the heritage of the past. Anticipation of undesirable future events played a crucial role in mobilizing collective efforts to move forward. We develop a model of future desirability in temporal work to identify how actors construct, link, and navigate interpretations of desirable and undesirable futures in their attempts to create a viable path of action. By conceptualizing temporal work based on the phenomenological quality of the future, we advance understanding of the strategic organization of time in pluralistic contexts characterized by uncertainty and urgency.


2002 ◽  
Vol 37 ◽  
pp. 117-132
Author(s):  
Hilary M. Carey

Time, according to medieval theologians and philosophers, was experienced in radically different ways by God and by his creation. Indeed, the obligation to dwell in time, and therefore to have no sure knowledge of what was to come, was seen as one of the primary qualities which marked the post-lapsarian state. When Adam and Eve were cast out of the garden of delights, they entered a world afflicted with the changing of the seasons, in which they were obliged to work and consume themselves with the needs of the present day and the still unknown dangers of the next. Medieval concerns about the use and abuse of time were not merely confined to anxiety about the present, or awareness of seized or missed opportunities in the past. The future was equally worrying, in particular the extent to which this part of time was set aside for God alone, or whether it was permissible to seek to know the future, either through revelation and prophecy, or through science. In the fourteenth and fifteenth centuries, the scientific claims of astrology to provide a means to explain the outcome of past and future events, circumventing God’s distant authority, became more and more insistent. This paper begins by examining one skirmish in this larger battle over the control of the future.


Philosophy ◽  
2009 ◽  
Vol 84 (2) ◽  
pp. 201-218 ◽  
Author(s):  
Tom Stoneham

AbstractThere are many questions we can ask about time, but perhaps the most fundamental is whether there are metaphysically interesting differences between past, present and future events. An eternalist believes in a block universe: past, present and future events are all on an equal footing. A gradualist believes in a growing block: he agrees with the eternalist about the past and the present but not about the future. A presentist believes that what is present has a special status. My first claim is that the familiar ways of articulating these views result in there being no substantive disagreement at all between the three parties. I then show that if we accept the controversial truthmaking principle, we can articulate a substantive disagreement. Finally, I apply this way of formulating the debate to related questions such as the open future and determinism, showing that these do not always line up in quite the way one would expect.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Hédi Ben Malek ◽  
Arnaud D’Argembeau ◽  
Mélissa C. Allé ◽  
Nicolas Meyer ◽  
Jean-Marie Danion ◽  
...  

Abstract People with schizophrenia experience difficulties in remembering their past and envisioning their future. However, while alterations of event representation are well documented, little is known about how personal events are located and ordered in time. Using a think-aloud procedure, we investigated which strategies are used to determine the times of past and future events in 30 patients with schizophrenia and 30 control participants. We found that the direct access to temporal information of important events was preserved in patients with schizophrenia. However, when events were not directly located in time, patients less frequently used a combination of strategies and partly relied on different strategies to reconstruct or infer the times of past and future events. In particular, they used temporal landmark events and contextual details (e.g., about places, persons, or weather conditions) less frequently than controls to locate events in time. Furthermore, patients made more errors when they were asked to determine the temporal order of the past and future events that had been previously dated. Together, these findings shed new light on the mechanisms involved in locating and ordering personal events in past and future times and their alteration in schizophrenia.


Philosophy ◽  
1983 ◽  
Vol 58 (226) ◽  
pp. 481-488
Author(s):  
Ralph W. Clark

Hume's sceptical arguments regarding induction have not yet been successfully answered. However, I shall not in this paper discuss the important attempts to answer Hume since that would be too lengthy a task. On the supposition that Hume's sceptical arguments have not been met, the empirical world is a place where, as the popular metaphor goes, all the glue has been removed. For the Humean sceptic, the only empirical knowledge that we can have is given to us in immediate perception. We have no reason to believe that the patterns of future events will in any way resemble patterns of events in the present or past. We have no reason to believe even that present events not observed resemble present events that are observed, or that knowledge of past and present can be any guide in making new discoveries about what took place in the past. What we have is an ideal setting for the calculation of a priori probabilities. We have a field of distinct events having no logical or evidential ties to one another. The attempt to justify induction that I wish to present is an appeal to a priori probability.


2019 ◽  
Vol 21 (8) ◽  
pp. 1520-1540 ◽  
Author(s):  
Ankit A Raut ◽  
J M Mallikarjuna

In-cylinder water injection is a promising approach for reducing NOx and soot emissions from internal combustion engines. It allows one to use a higher compression ratio by reducing engine knock; hence, higher fuel economy and power output can be achieved. However, water injection can also affect engine combustion and emission characteristics if water injection and injector parameters are not properly set. Majority of the previous studies on the water injection are done through experiments. Therefore, subtle aspects of water injection such as in-cylinder interaction of water sprays, spatial distribution of water vapor, and effect on flame propagation are not clearly understood and rarely reported in literature due to experimental limitations. Thus, in the present article, a computational fluid dynamics investigation is carried out to analyze the effects of direct water injection under various injector configurations on water evaporation, combustion, performance, and emission characteristics of a gasoline direct injection engine. The emphasis is given to analyze in-cylinder water spray interactions, flame propagation, water spray droplet size distribution, and water vapor spatial distribution inside the engine cylinder. For the study, the water-to-fuel ratio is varied from 0 to 1. Various water injector configurations using nozzle hole diameters of 0.14, 0.179, and 0.205 mm, along with nozzle holes of 4, 5, 6, and 7, are considered for comparison in addition to the case of no_water. Computational fluid dynamics models used in this study are validated with the available data in literature. From the results, it is found that the emission and performance characteristics of the engine are highly dependent on water evaporation characteristics. Also, the water-to-fuel ratio of 0.6 with 6 number of nozzle holes and the nozzle diameter of 0.14 mm results in the highest indicated mean effective pressure and the lowest NOx, soot, and CO emissions compared to other cases considered.


2019 ◽  
Vol 212 ◽  
pp. 121-134 ◽  
Author(s):  
Liping Tian ◽  
Mengyuan Wang ◽  
Xiao Zhang ◽  
Xiaoqiang Yang ◽  
Yongqiang Zong ◽  
...  
Keyword(s):  

1982 ◽  
Vol 15 (02) ◽  
pp. 180-186 ◽  
Author(s):  
Joseph LaPalombara

Political scientists are only now, and dimly, beginning to recognize that something called “political risk analysis” (PRA) is very much in vogue in the corporate and banking communities of this country. Any attempt to assess this uncommon development should begin with this question: Why would any banker or corporate manager wish to spend hard cash on anything political scientists might have to say about places overseas where banks and multinational corporations lend or invest their capital? After all, the profession is not exactly distinguished by its ability to make accurate forecasts. Indeed, Sartori has argued that political scientists ought to eschew forecasting entirely in that they are best able to explain what happened as opposed to what may come to pass.Sartori's assertion of course would make historians of us all—and burden us with the historian's smug claim that, if the history examined is too recent, the immediacy of events will distort our vision and bias our judgments. Thus, rather than try to foretell where, say, Germany will move politically next year we should expend (more!) of our resources to establish once and for all what really caused Weimar to collapse and Hitler to come to power.This is not the stuff of political risk analysis. Growing interest in this activity is little based on broad analyses of the past or on long-term forecasts of future events. The potential consumers of political assessments are intelligent, harried bankers and corporate managers who are pressed to make relatively short-term decisions that affect the viability of enterprise and investment-and, equally important, careers-in professions where tenure is unknown.


2016 ◽  
Vol 27 (4) ◽  
pp. 421-434 ◽  
Author(s):  
Prescott Breeden ◽  
Dorothea Dere ◽  
Armin Zlomuzica ◽  
Ekrem Dere

AbstractMental time travel (MTT) is the ability to remember past events and to anticipate or imagine events in the future. MTT globally serves to optimize decision-making processes, improve problem-solving capabilities and prepare for future needs. MTT is also essential in providing our concept of self, which includes knowledge of our personality, our strengths and weaknesses, as well as our preferences and aversions. We will give an overview in which ways the capacity of animals to perform MTT is different from humans. Based on the existing literature, we conclude that MTT might represent a quantitative rather than qualitative entity with a continuum of MTT capacities in both humans and nonhuman animals. Given its high complexity, MTT requires a large processing capacity in order to integrate multimodal stimuli during the reconstruction of past and/or future events. We suggest that these operations depend on a highly specialized working memory subsystem, ‘the MTT platform’, which might represent a necessary additional component in the multi-component working memory model by Alan Baddeley.


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