Gravity Survey along the Mizuho Traverse Routes, East Antarctica: SEAL Seismic Exploration in 1999-2000

A gravity survey was conducted along the Mizuho traverse routes in austral summer of 1999-2000 by the 41st Japanese Antarctic Research Expedition (JARE-41). The main purpose of the survey was to obtain detail gravity anomaly along the traverse routes, where deep seismic exploration was simultaneously conducted in order to obtain a fine crustal structure of the Mizuho Plateau. By using SCINTREX (CG-3M) gravity meter, the survey was carried out at 160 sites with about 1 km interval in a distance of 190 km from S16 to Z20 on the traverse routes. Free-air and Bouguer anomalies were calculated using precise locations by GPS measurements, by taking into account an effect of the thick icesheet. The furrowed negative Free-air anomalies are identified around H192, where middle points of the whole traverse routes. Two bedrock elevation models derived both by seismic refraction analyses and radio-echo sounding might correspond to the bottom and the top of a mixture layer composed from ice-moraine rocks over the bedrock surface. Thickness of the crust estimated by Bouguer anomalies is 0.5 - 1 km larger toward inland at the terminal point of Z20 along the profile.

Gravity Survey on the Mizuho Plateau, East Antarctica: SEAL Seismic Exploration in 2001-2002

A gravity survey on Mizuho Plateau was carried out in austral summer of 2001-2002 by the 43rd Japanese Antarctic Research Expedition (JARE-43), as one of the geophysical measurements of deep seismic exploration. Gravity measurements were conducted at 151 points in approximately 1 km interval along the 150 km profile. Considering the gravity effect from the ice-sheet, Free-air and Bouguer anomalies were calculated by using precise GPS locations. Furrowed and basin-like negative Free-air anomalies were observed in middle and northern parts of the profile. Bouguer anomalies were calculated by two bedrock elevation data obtained from seismic refraction and radio-echo sounding. High resolution model for bedrock elevation by radio-echo sounding was applied in determining the crustal thickness.

Quantitative relationship between surface sedimentary diatoms and water depth in North-Central Bohai Bay,China

To study the quantitative relationship between surface sedimentary diatoms and water depth,67 surface samples were collected for diatom analysis on eight profiles with water depth variation from the muddy intertidal zone to the shallow sea area in North-Central Bohai Bay,China.The results showed that the distribution of diatoms changed significantly in response to the change in water depth.Furthermore,the quantitative relationship between the distribution of dominant diatom species,their assemblages,and the water depth was established.The water depth optima for seven dominant species such as Cyclotella striata/stylorum,Paralia sulcata,and Coscinodiscus perforatus and the water depth indication range of seven diatom assemblages were obtained in the study area above the water depth(elevation)of-10 m.The quantitative relationship between surface sedimentary diatoms and water depth provides a proxy index for diatom-paleo-water depth reconstruction in the strata in Bohai Bay,China.

Developing High-Precision Maps for Automated Driving in China:Legal Obstacles and the Way to Overcome Them

A high-precision map(HPM)is the key infrastructure to realizing the function of automated driving(AD)and ensuring its safety.However,the current laws and regulations on HPMs in China can lead to serious legal compliance problems.Thus,proper measures should be taken to remove these barriers.Starting with a complete view of the current legal obstacles to HPMs in China,this study first explains why these legal obstacles exist and the types of legal interests they are trying to protect.It then analyzes whether new technology could be used as an alternative to resolve these concerns.Factors such as national security,AD industry needs,and personal data protection,as well as the flexibility of applying technology,are discussed and analyzed hierarchically for this purpose.This study proposes that China should adhere to national security and AD industry development,pass new technical regulations that redefine the scope of national security regarding geographic information in the field of HPMs,and establish a national platform under the guidance and monitoring of the government to integrate scattered resources and promote the development of HPMs via crowdsourcing.Regarding the legal obstacles with higher technical plasticity,priority should be given to technical solutions such as“available but invisible”technology.Compared with the previous research,this study reveals the current legal barriers in China that have different levels of relevance to national security and different technical plasticity.It also proposes original measures to remove them,such as coordinating national security with the development of the AD industry,reshaping the boundary of national security and industrial interests,and giving priority to technical solutions for legal barriers that have strong technical plasticity.

Digital Soil Mapping Using Artificial Neural Networks and Terrain-Related Attributes

Detailed soil surveys involve costly and time-consuming work and require expert knowledge. Since soil surveys provide information to meet a wide range of needs, new methods are necessary to map soils quickly and accurately. In this study, multilayer perceptron artificial neural networks(ANNs) were developed to map soil units using digital elevation model(DEM) attributes. Several optimal ANNs were produced based on a number of input data and hidden units. The approach used test and validation areas to calculate the accuracy of interpolated and extrapolated data. The results showed that the system and level of soil classification employed had a direct effect on the accuracy of the results. At the lowest level, smaller errors were observed with the World Reference Base(WRB)classification criteria than the Soil Taxonomy(ST) system, but more soil classes could be predicted when using ST(7 soils in the case of ST vs. 5 with WRB). Training errors were below 11% for all the ANN models applied, while the test error(interpolation error) and validation error(extrapolation error) were as high as 50% and 70%, respectively. As expected, soil prediction using a higher level of classification presented a better overall level of accuracy. To obtain better predictions, in addition to DEM attributes, data related to landforms and/or lithology as soil-forming factors, should be used as ANN input data.