Ionospheric disturbances over Japan due to the 18 May 1980 eruption of Mount St. Helens

The effects of the Mount St. Helens eruption at 1532 UT on 18 May 1980 on the ionosphere over Japan are examined using data on total electron content obtained at three closely-spaced stations and HF (5 and 8 MHz) Doppler recordings together with microbarograph data for the surface pressure perturbation. The results strongly suggest that ionospheric perturbations having a predominant period of about 9 min propagated from north to south approximately along the great circle path with a horizontal velocity of about 300 m s⁻¹. The observed time variations of perturbations can be well explained in terms of Lamb waves propagating through the atmospheric sound channel while launching up-going waves to produce the ionospheric oscillations.     

Origins of the St Helens Glass Industry

Abstract

‘No time for stirs in the Church’     

成都市商业街墓葬的问题

成都市商业街独木棺与船棺葬是近年的一个重要考古发现,现已公布为全国重点物保护单位。本对这次考古发现出土的葬具和器物作了深入考证和探析,对墓葬的年代和化内涵提出了一些独到的见解。     

Time evolution of the optical effects and aerosol characteristics of Mt. Pinatubo origin from ground-based observations

The time evolution of the perturbations in aerosol spectral optical depths associated with the Mt. Pinatubo volcanic eruption of June 1991 is investigated using a ground-based multiwavelength solar radiometer at the tropical station, Trivandrum. The spectral optical depths of the volcanic aerosols deduced from the radiometer data are inverted to retrieve the size distributions of the particles, from which the effective radius and columnar mass loading are estimated. Observations showed that during the initial phase (within one year after the eruption) the optical depths showed fluctuations with two peaks, one in November 1991 and another in February 1992 superposed over a very weak decreasing trend. During this period, the size distributions have been generally bimodal, with a secondary large particle mode occurring at ∼0.75 μm, and the columnar mass loading varied between about 170 and 110 mg m⁻². The optical depths and mass loading decreased with an e-folding time of about 15 months. The effective radius is found to increase from ∼0.35 μm in September 1991 to ∼0.60 μm in October 1992 and then remain rather steady, while the mass loading decreased to reach near-background levels (within error limits) by early 1993.     

成都商业街船棺出土漆器及相关问题探讨

商业街船棺出土漆器与楚漆器相比有相似之处,但区别是十分明显的。商业街船棺出土漆器的纹饰完全是模仿同时期中原式青铜器上的蟠螭纹和红铜镶嵌的龙纹。题材单一,缺少变化,从漆器的这些特征推测,战国早期前后的蜀国青铜器中应有较多中原风格的青铜器,说明蜀的上层统治向慕中原化。     

HF Doppler observations of gravity waves during the 16 February 1980 solar eclipse

Observations by the HF Doppier technique of the ionospheric effects of the 16 February 1980 solar eclipse in Africa are presented. Some oscillations which are detected at two stations can be attributed to a travelling coherent structure. Its characteristics are consistent with a gravity wave generated by the eclipse.     

Ionospheric electron content observations during the total solar eclipse of February 16, 1980

Observations on the Faraday rotation of a transionospheric VHF signal obtained from a network of four stations near the path of totality during the total solar eclipse of 16 February 1980 are reported. A small decrease of 3–4% in the total ionization has been obtained around the time of totality. Absence of any periodic structure following the eclipse indicates that the TIDs are not of significant amplitude in the present case to be detected by the Faraday rotation technique.     

Ionospheric and atmospheric disturbances around Japan caused by the eruption of Mount Pinatubo on 15 June 1991

The disturbances observed by the Japanese ionospheric observation network following the explosions of Mount Pinatubo on 15 June 1991, are presented. Remarkable ionospheric fluctuations with periods of about 20 min appeared in the records of HF Doppler and total electron content (TEC) data. Traveling wave fronts of ionospheric disturbances scaled from these data give a northward horizontal velocity of 290 m/s. The surface pressure fluctuations due to the passage of atmospheric waves were confirmed by the microbarograph chain data in Japan. There existed three kinds of northward traveling pressure fluctuations; short-period (2–5 min) fluctuations with a horizontal velocity of 290 m/s, long-period (8–10 min) fluctuations with 300 m/s, and 17-min fluctuations with 281 m/s. It is concluded that the ionospheric and surface pressure waves were caused by the eruption of Mount Pinatubo.     

A Village at the Foot of Mt.Meli

ＡＶｉｌｌａｇｅａｔｔｈｅＦｏｏｔｏｆＭｔ．ＭｅｌｉＺＨＯＵＺＨＥＮＧＳｋｉｒｔｅｄｂｙｔｈｅＬａｎ－ｃａｎｇｊｉａｎｇａｎｄＮｕ－ｊｉａｎｇｒｉｖ－ｅｒｓ,ＭｅｌｉＭｏｕｎｔａｉｎｓｔａｎｄｓｍａ－ｊｅｓｔｉｃａｌｌｙａｔｔｈｅｂｏｒｄｅｒｂｅｔｗ...     

A Multidisciplinary Study on the Seismic Vulnerability of St. Agostino Church in Amatrice following the 2016 Seismic Sequence

ABSTRACT

The big earthquake of August 24, 2016 and subsequent major shocks severely damaged many historic villages in Central Italy and dramatically showed the intrinsic vulnerability of the diffused architectural heritage. The St. Agostino church is one of the collapsed historical buildings, being inside the epicentre village of Amatrice. During the long seismic earthquake swarm, progressively the church was damaged and monitored. This multidisciplinary study of the damage of the church includes correlations of all the data derived from three steps geomatics surveys (3D aerial and terrestrial models): the archival drawings and images documenting previous events distressing the building, the previous strengthening intervention, and finally the seismic site response analysis (from Amatrice’s accelerometric station). Through a back analysis carried out by a finite elements model, it was possible to understand the seismic vulnerability of this historical building, in relation to the previous interventions and damage events. The proposed methodology, based on the interdisciplinary data analysis, provides useful information for the next strengthening projects of damaged historical monument.     

St. Leon and the culture of the heart

This essay reads Godwin's second novel, St. Leon (1799), as an attempt to counter the asperity he expresses towards the domestic affections in his political philosophy of the 1790s. In St. Leon, Godwin seeks to square his newfound interest in the affections as a topic for fiction with his commitment to an anti-establishment political agenda. Though it is presented as a ‘eulogium’ to ‘the affections and charities of private life’, the narrative persistently undercuts the potential for the affections to stimulate readerly curiosity. The focus of the novel constantly shies away from the domestic scene, and instead propels the momentum forwards to the alchemical adventures that precipitate the disintegration of the very affections the novel purports to eulogise. The novel thus plays out Godwin's complicated desire to embrace, and yet simultaneously to deny, the importance of private emotions in the pursuit of political justice.